Fraunhofer Institutefor Solar Energy Systems ISE

Agrivoltaics: Opportunities for
Agriculture and the Energy Transition
A Guideline for Germany | February 2024

Publishing notes

Published by
Fraunhofer Institute for Solar Energy Systems ISE
Heidenhofstrasse 279110 Freiburg, Germany
Phone +49 761 4588-0
www.ise.fraunhofer.deAuthors
Dr. Max Trommsdorff (Fraunhofer ISE)
Simon Gruber (Fraunhofer ISE)
Tobias Keinath (Fraunhofer ISE)
Michaela Hopf (Fraunhofer ISE)
Charis Hermann (Fraunhofer ISE)
Frederik Schönberger (Fraunhofer ISE)Charlotte Gudat (Fraunhofer ISE)
Alexa Torres Boggio (Fraunhofer ISE)
Moritz Gajewski (Fraunhofer ISE)
Adj. Prof. Petra Högy (University of Hohenheim)
Dr. Sabine Zikeli (University of Hohenheim)
Andrea Ehmann (University of Hohenheim)
Dr. Axel Weselek (University of Hohenheim)
Prof. Ulrich Bodmer (Weihenstephan-Triesdorf Universityof Applied Sciences)
Dr. Christine Rösch (Karlsruhe Institute of Technology, KIT)
Dr. Daniel Ketzer (Karlsruhe Institute of Technology, KIT)
Nora Weinberger (Karlsruhe Institute of Technology, KIT)
Dr. Stephan Schindele (BayWa r.e.)Jens Vollprecht, attorney, graduate of forest management studies(Becher Büttner Held PartGmbB)
APV-RESOLA project advisory board
Hans-Josef Fell (Energy Watch Group),
Chair APV-RESOLA project advisory board
Sylvia Pilarsky-Grosch (Bund für Umwelt- und Naturschutz, BUND)
Franz Pöter (Solar Cluster Baden-Württemberg e. V.)
Prof. Adolf Goetzberger (Fraunhofer ISE, Director; retired)
Ralf Ries (GLS Gemeinschaftsbank eG)
Manfred Oetzel (State Farmers’ Association
Baden-Württemberg)
Dr. Florian Brahms (attorney, energy law)
Dr. Winfried Hoffmann (Applied Solar Expertise, ASE)
Prof. Daniel Buhr (University of Tübingen)Special thanks to
Hofgemeinschaft Heggelbach
Solar Consulting GmbH
Forschungszentrum Jülich GmbH
inter 3 — Institute for Resource Management
Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e. V.
Hilber Solar GmbHAMA FILM GmbH
Design and typesetting
netsyn, Freiburg
Note
This guideline provides information on the potential ofagrivoltaics, including the latest technologies and regulatory
frameworks in this area. It also offers practical tips on how
agrivoltaics can be used by farmers, municipalities andcompanies. This guideline is not intended to be exhaustive.
All the application methods presented in this document should
be taken as examples. Great care has been taken in preparing
this guideline; nevertheless, those involved in its preparation
assume no liability for its contents. Each agrivoltaic project
must be examined on a case-by-case basis during its planningand implementation stages, with technical, economic and legal
advice sought if needed.
© Fraunhofer Institute for Solar Energy Systems ISE,
Freiburg, 2024

PDF version of theagrivoltaics guideline

Third edition, February 2024iForeword (2022)

Dear readers,
Crops need sun, and so do photovoltaic systems. We are allaware that renewable energies need to be expanded at a much
faster rate if we are going to meet our climate targets. We
need six to eight times more solar energy than we currently
produce, both on roofs and open land. In the past, this usuallymeant having to choose between agriculture or renewableenergies, but now we have an innovative solution to thisdilemma: agrivoltaics. With this promising technology, solar
cells positioned over a field can generate electricity while
grain, fruit and vegetable crops grow underneath. This enables
the dual use of land. Sharp technical expertise enables us toexpand photovoltaics without depriving farmers of valuable
land. And what’s more, this special photovoltaic system offers
them a new income stream, and it boosts resilience.
Farmers have been dealing with the effects of climate change
for many years now. The uptick in extreme weather has a huge
impact on agriculture more than virtually any other industry,
with conditions being too dry and hot at times, while at othertimes unexpected hailstorms can threaten crops. This is where
photovoltaic systems can help. They can slow hailstones
and provide shade, saving crops from dehydration causedby overexposure to the sun. These are the benefits that one
research project has documented.

As members of the German federal government, we will be
helping expand agrivoltaics with better support schemes. In
April there will be an innovation tender which will establish
Germany’s first feed-in tariff specifically for agrivoltaic systems
in accordance with the German Renewable Energy Sources Act(Erneuerbare-Energien-Gesetz, EEG). This includes the updated
implementing regulation for CAP direct payments. As a result,
we are helping farms that install agrivoltaic systems to continue
receiving 85 percent of the premiums for agricultural land use.
Although many of the basic issues around this new technology
have now been addressed, some questions remain unanswered:
Can agrivoltaic systems be effectively combined with thecultivation of specialty crops, such as berries? Are there
solutions for greenhouses? How do we establish broad public
support for agrivoltaics? A key research project run by the
Fraunhofer Institute for Solar Energy Systems ISE and its
partners started in 2022.

This updated guideline will give you the latest insights into thistechnology from research and real-life operations. It outlines theopportunities for agrivoltaics and reviews current developmentsin this area. In doing so, we are making key progress toward
standardizing these systems and thus ensuring quality.

Other countries have also identified the opportunities inagrivoltaics. Dual-use areas for agriculture and solar power
generation are now an integral part of the landscapes in some
Asian countries, while France is championing this technology
in Europe. We are focusing on the potential of innovations like
agrivoltaics in Germany, too. After all, the principle behind it isso simple and so compelling. Arable land stays arable land, andthe photovoltaic system stands over it, ensuring our basic needs
are covered for the future. As a result, the German federal
government is creating a win-win-win situation: for climate, theenvironment and our farming industry. Prepare to be inspired!

Bettina Stark-Watzinger

Cem ÖzdemirMember of the German Federal Parliament (Bundestag)Member of the German Federal Parliament (Bundestag)Federal Minister of Education and Research

German Federal Minister for Food and Agriculture

Photo: © German federal government / Guido Bergmann

Photo: © BMEL / Janine Schmitz / Phototek

1

Content

1

Resource-efficient land use with agrivoltaics ������������������������������������������������������������ 4

2

Agrivoltaics facts and figures �������������������������������������������������������������������������������������� 8
2.1 Agrivoltaics: A new approach to mitigate competing demands for land use �������������� 9
2.2 Precipitation and global radiation ���������������������������������������������������������������������������� 9
2.3 Definition and potential of agrivoltaics �������������������������������������������������������������������� 10
2.4 Research sites in Germany �������������������������������������������������������������������������������������� 13
2.5 Operational sites in Germany �������������������������������������������������������������������������������� 20
2.6 Research projects in Germany �������������������������������������������������������������������������������� 23
2.7 International development �������������������������������������������������������������������������������������� 26

3Agriculture ������������������������������������������������������������������������������������������������������������������ 30
3.1 Results from the APV-RESOLA research project ������������������������������������������������������ 31
3.2 Crop selection and cultivation �������������������������������������������������������������������������������� 32
3.3 Reports from farmers �������������������������������������������������������������������������������������������� 37

4

Profitability and business models ������������������������������������������������������������������������������ 38
4.1 Capital expenditure ���������������������������������������������������������������������������������������������� 39
4.2 Operating costs ������������������������������������������������������������������������������������������������������ 40
4.3 Levelized cost of electricity ������������������������������������������������������������������������������������ 41
4.4 Self-consumption and revenue from power generation ������������������������������������������ 41
4.5 Business models ���������������������������������������������������������������������������������������������������� 42

5

Technology ������������������������������������������������������������������������������������������������������������������ 44
5.1 Approaches to agrivoltaic system construction ������������������������������������������������������ 45
5.2 PV module technologies ���������������������������������������������������������������������������������������� 46
5.3 Mounting system and foundation �������������������������������������������������������������������������� 47
5.4 Light management ������������������������������������������������������������������������������������������������ 49
5.5 Water management ����������������������������������������������������������������������������������������������� 50
5.6 Size of the PV system �������������������������������������������������������������������������������������������� 50
5.7 Approval, installation and operation ���������������������������������������������������������������������� 512

6Society ������������������������������������������������������������������������������������������������������������������������ 54
6.1 Engaging citizens and stakeholder groups ������������������������������������������������������������ 55
6.2 Context-specific acceptance ���������������������������������������������������������������������������������� 55
6.3 Two examples for dialogue and engagement ���������������������������������������������������������� 56
6.4 Success factors ������������������������������������������������������������������������������������������������������ 58

7

Policy and legislation �������������������������������������������������������������������������������������������������� 60
7.1 EU direct payments ������������������������������������������������������������������������������������������������ 61
7.2 Requirements of public-sector construction law ���������������������������������������������������� 61
7.3 Inheritance tax, gift tax, property tax and land transfer tax �������������������������������������� 63
7.4 Renewable Energy Sources Act (Erneuerbare‑Energien-Gesetz) 2023 ���������������������� 64

8

Promoting agrivoltaics ���������������������������������������������������������������������������������������������� 70

9Bibliography and sources ������������������������������������������������������������������������������������������ 72
9.1 Sources ���������������������������������������������������������������������������������������������������������������� 72
9.2 List of figures �������������������������������������������������������������������������������������������������������� 74
9.3 List of tables ���������������������������������������������������������������������������������������������������������� 76
9.4 Acronyms �������������������������������������������������������������������������������������������������������������� 76
9.5 Links to further information ������������������������������������������������������������������������������������ 76

3

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

1

Resource-efficient land
use with agrivoltaics

The global population is growing — and demand for food is
growing along with it. At the same time, land for installing
more ground-mounted PV systems is urgently needed to tackle
the climate crisis.[1] There is growing competition for space,especially in densely populated areas.
The demand for space to build ground-mounted PV systems
is becoming an increasingly decisive factor as falling costs
have now made them economically viable, even withoutstate subsidies. The climate crisis is also presenting ever morechallenges to farming. Water scarcity, extreme weather andoverall rising temperatures necessitate new measures to protect
crops and soils from adverse conditions. Many farms are understrain from regulatory frameworks and economic uncertainty.
This significantly limits the scope for protecting water andwildlife on the one hand and stabilizing or even increasing crop
yields on the other.

Dual use of agricultural land
Agrivoltaics could mitigate competition in the future for space
through dual use of land. It offers the possibility of installing
large PV systems on open land while keeping the ground clear
for food production. This dual use of land for agriculture andphotovoltaics can be particularly beneficial for areas that aregood for farming due to their fertile soil and temperate climate
and are a suitable location for ground-mounted PV systems
because they receive high levels of solar radiation.
Solar energy is becoming an integral pillar of the energy supply
for the future alongside wind power, so there is seemingly anurgent need to integrate PV systems effectively into different
areas of human activity with good public backing. Calculations
by the Fraunhofer Institute for Solar Energy Systems ISE showthat the installed PV capacity in Germany needs to be increased
by a factor of six to eight by 2045 if the country’s energy
system is to become climate neutral[2].

Fig. 1: Agrivoltaic research site at Lake Constance© Fraunhofer ISE

3

2

Fig. 2: Illustration ofan agrivoltaic system

1© Fraunhofer ISE

Technical self-consumption in
future incl. energy storage system

Prof. Adolf Goetzberger, founder of Fraunhofer ISE, and
Dr. Armin Zastrow were the first to propose this kind of
dual land use with their 1981 article “Kartoffeln unter dem
Kollektor” (potatoes under the collector), which appearedin the “Sonnenenergie” journal[3]. In 2014, the innovationgroup APV-RESOLA (“Agrivoltaics: contribution to resourceefficient land use”) took this idea and expanded on it withfurther research. The German Federal Ministry of Education
and Research (BMBF) funded the project as part of the FONA
research program, which looks at sustainable development.
This resulted in a pilot project at Heggelbach farm near Lake
Constance. The project investigated the economic, technical,
social and environmental aspects of agrivoltaic technology inreal-world conditions, with the aim of demonstrating its basic
feasibility.
The project partners were: Fraunhofer ISE (management andcoordination), the University of Hohenheim, the Institute forTechnology Assessment and Systems Analysis (ITAS)[4] basedat the Karlsruhe Institute of Technology (KIT), BayWa r.e. Solar
Projects GmbH, Regionalverband Bodensee-Oberschwaben,
Elektrizitätswerke Schönau, and Hofgemeinschaft Heggelbach.

Direct marketing in local
residential neighborhoods

Power fed into electricity
grid and gas network

The system on the Heggelbach site is installed on arable land
covering one third of a hectare and features 720 bifacial
PV modules with a 5 m clearance, providing an installedcapacity of 194 kilowatt peak (kWp). The project showed thatwith the PV system, land-use efficiency rose 60 to 86 percent,and crops adapted more effectively during dry spells in 2017and 2018. Further research on the site is ongoing.
The purpose of this guideline
This guideline is based on the key outcomes from the
APV‑RESOLA research project, and this third edition
incorporates results from other studies and research projects.
It provides information on the benefits and opportunities
presented by agrivoltaics, gives an overview of its potential andcurrent state of the art, and offers practical advice for farmers,
municipalities and companies on how to use the technology.
It also presents case studies from successful projects, outlines
the challenges in using agrivoltaics in Germany and proposes
ways to promote agrivoltaics in Germany in future.

Fig. 3: Partners in the
APV-RESOLA project5

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

A brief history of agrivoltaics
Agrivoltaic technology has developed rapidly over the last
few years and is now available in most parts of the world.
Its installed capacity has increased exponentially from around5 megawatt peak (MWp) in 2012 to at least 14 gigawatt
peak (GWp) in 2021. Government funding programs in Japan(since 2013), China (around 2014), France (since 2017),
the USA (since 2018) and most recently in South Korea havemade these advances possible[5].

International
Annual “AgriVoltaics”
conference established

2020
Germany

France and Italy

China

USA

Adolf Goetzberger’s agrivoltaic
concept first publishedFirst large-scale agrivoltaic
systems in Europe

First large agrivoltaic
systems > 10 ha

First US program tosupport agrivoltaics
in Massachusetts

2011

1981

2004

2015

2013

Definition of agrivoltaics toensure primary agricultural use(DIN SPEC 91434)

2021

2023

2017

2021

Germany

Japan

Italy

First agrivoltaic system
in Germany

FranceGlobalFirst government
funding program

Government funding
for agrivoltaics

Installed capacity
estimated to beover 14 GWp

EU Commission
approves 1.7 billion
euros in funding
for agrivoltaics

Fig. 4: How agrivoltaics has developed since 1981 © Fraunhofer ISE

Opportunities for agrivoltaics
In addition to increasing land-use efficiency, agrivoltaics canboost resilience and crop yields if the systems have the righttechnical design. Research has demonstrated such effects, suchas in the APV-RESOLA project. Fruit and specialty crops that are
being increasingly damaged by hail, frost and drought can also
benefit from the protection offered by the PV modules, which
partially cover the crops[6].
More potential synergies between PV and agriculture can beharnessed, including:
reducing irrigation demand by up to 20 percent[7];collecting rainwater for irrigation;
reducing wind erosion;using the PV system’s mounting system to attach protective
nets or sheets;
optimizing the available light for crops by using solar
tracking PV systems, for instance;increasing PV module efficiency through improved
convective cooling;increasing the efficiency of bifacial PV modules, which
use light from both sides to generate electricity, thanks togreater distances between the ground and the adjacent PV
module rows.

6

2018

Germany

Agrivoltaics can create added value locally and benefit
rural development. It also gives farms the opportunity to
produce green, solar-generated electricity for their own local
consumption, reducing the need to purchase expensive
electricity from the grid and cutting their overall expenditure on
power. Agrivoltaics also enables farms to create another sourceof income if they sell the electricity that they generate.
Challenges: barriers to implementing agrivoltaics
Funding for market development and for more research
projects makes good sense, as this will allow researchers to
draw firmer conclusions about the possible synergies andacceptance issues for the different approaches to agrivoltaics.
This will also enable them to examine the non-technicaland social success factors and the economic and ecologicalrisks and opportunities in greater detail. At the same time,these projects can make investors more willing to invest andencourage stakeholders, citizens and commercial enterprises
to develop creative solutions. Section 7 discusses possible areas
for action in policymaking.

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

In recent years, a framework has been established inGermany that benefits agrivoltaic systems and gives thema realistic chance of being implemented. But if projects
are to be realized, it is not only the German Building Code(Baugesetzbuch, BauGB) that is relevant, but also the influenceof regional planning and land use policy. There are significant
differences between the federal states when it comes to the
responsible authorities and institutions. In addition to theconstruction law framework, it is also necessary to harmonize
feasible instructions for authorities, regional plans and statedevelopment plans, and to support the development ofsolutions so that the market launch is sustainable.

Requirements
Zoning plan: Classify agrivoltaic systems as “special area:
agrivoltaics” instead of an “electrical facility/commercialarea” on zoning plans to avoid them being wrongly
recorded as areas covered with an impervious surface
Extend areas that are classified for agrivoltaics use toinclude all agricultural land as part of the EEG
Run an agrivoltaics R&D program for Germany
Engage as many citizens and stakeholder groups as
possible at an early stage to analyze the non-technicalsuccess factors in building an agrivoltaic system, andidentify suitable locations

Overview of agrivoltaics
Global installed capacity of at least 14 GWp
Estimated potential for stilted, overhead agrivoltaic systems
in Germany is roughly 1700 GWp

Advantages
Combines agriculture and ground-mounted PV systems
Offers additional benefits for farming, including protection
against storm, hail, frost and drought damage
Has a lower levelized cost of electricity (LCOE) compared tosmall rooftop PV systems
Diversifies income for farmers
30 / 70(< 1% each)3840(13 %)
7470

7000
800

6000

600

17,940(hectares)(26 %)(61 %)

5866

5397

5000
(hectares)

3439

4000
3000
2091

904

2000

1538

1000
0

72
580

535
240

2004

2005

2006

2007

2008

	Land-use conversion, misc. physical structure	Arable land, less-favored area as of 2016
	German Institute for Federal Real Estate (BImA)

340

1100

795

523

2009

2010

	Area used fortransportation
	Other

2011

2012

2013

2014

207
823

2015

27
171
669

2016

35
140
302

18
33
140
467

260

358

2017

2018

Fig. 5: Land used for ground-mounted PV systems in Germany
since 2004; total land used and yearly expansion © Federal
Ministry for Economic Affairs and Climate Action BMWK [8]7Agrivoltaics: Opportunities for Agriculture and the Energy Transition

2

Agrivoltaics facts and figures

Solar PV and wind power will be cornerstones of the futureenergy supply. Photovoltaics is now the most affordable
renewable energy technology, with prices for PV modules
having fallen by around 90 percent between 2009 and2019. The levelized cost of electricity (LCOE) is currently
4–11 euro cents per kilowatt hour, depending on the sizeof the system.
Solar power also enjoys strong backing from the public.
However, solar PV needs a relatively large amount of spacecompared to wind power and fossil fuels, so it is usuallydifficult to find the right areas to build large PV systems.
One solution to this problem is integrating PV systems into
different areas of human activity, such as on buildings, lakes
and land with impervious surfaces, like areas for transportation.
Doing so can make the areas dual purpose, and in the caseof agrivoltaics, it significantly reduces land use. It does nothave to be a choice between photovoltaics or photosynthesis;
the two can complement each other well.
Fig. 6: Applications for integrated photovoltaics© Fraunhofer ISE

Germany had around 59 GWp installed PV capacity by the endof 2021, 75 percent of which came from rooftop systems, withthe rest from ground-mounted systems[9]. But this is not nearlyenough: Fraunhofer ISE has calculated that Germany needs
between 300 and 450 GWp of installed capacity by 2045.
Integrating PV technology into buildings, vehicles and transportroutes and using it on agricultural land, bodies of water and in
urban spaces could unlock huge yield potential.
Several factors determine how much of the technically feasible
potential can be tapped from a practical and commercial
point of view, including regulatory and economic contexts.
The LCOE with integrated PV is likely to be higher than withsimple, large‑scale ground-mounted PV systems, but integrated
PV eases competition for land use and can create synergies.
For instance, it can be a substitute for a building facade or
use the existing structure of a noise barrier. It can increase
the range of electric vehicles or make agricultural land dual
purpose. With all scenarios, the bigger a PV system’s added
value is, the more successful its integration will be.

Fig. 7: Typical ground-mounted PV system © Fraunhofer ISE

8

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Agrivoltaics: A new approach to mitigate
competing demands for land use

Ground-mounted PV systems can create competition
for the use of agricultural land. Although EEG-funded
ground‑mounted PV systems may only be constructed on landwith impervious surfaces, in conversion areas, on strips of landalong highways or railroad tracks and on land in (agriculturally)
constrained areas within the scope of the tender, large
PV systems are also being constructed outside the scope of
EEG‑compliant tenders due to the enormous reduction in the
LCOE for solar energy, negating the EEG’s aim to incentivize
the protection of valuable agricultural land.

Precipitation (mm / a)Considering the limited availability of arable land, the increasing
demand for space locally may exacerbate competition for land
use and trigger social, political, economic and environmental
conflicts. With this in mind, it would be prudent to discuss the
future importance of rural areas as sites for new technologies
so as to mitigate potential competing goals and inconsistencies
in valuation. Research and development in agrivoltaics is a key
undertaking with respect to the requirements of the High‑TechStrategy 2025 pursued by the German Federal Ministry of
Education and Research (BMBF).

2.2

Precipitation and global radiation

According to long-term measurements taken across Germany
since 1880, there has been an average annual increase inprecipitation of 8 percent. However, there has been a clear
downward trend in precipitation over the last 30 years. Data
from the Deutscher Wetterdienst (German meteorologicalservice, DWD)[10] shows a yearly decline in precipitation of
0.39 percent since 1991. The average amount of rainfall
has therefore fallen by almost 12 percent between then andnow (see figure 8, blue trend line). Weather conditions inspring, which are key for crop growth, have fundamentallychanged. Over the last 12 years, the amount of rainfall in
April has sometimes been up to 70 percent less than thehistorical average for the month. Warm weather in spring isincreasingly leading to soil moisture deficit early in the year,
which cannot be rectified later in summer[11]. Data analysis also
clearly shows that global solar radiation (the sum of direct anddiffuse radiation) increased by 0.28 percent yearly in the same
period (red trend line), which is a positive development for
PV yields. The combination of decreasing precipitation levels
and increasing global radiation suggests that as time passes
agrivoltaics will become an increasingly ideal solution to makeagricultural systems more resilient to climate change and turnclimate impacts to good account.

1,100

1,300

1000

1200

900

1100

800

1000

700

900

Global solar radiation (kWh / m2a)

2.1

800

600
1990

2000

2010
Precipitation

2020

Global solar radiation

Fig. 8: Precipitation and global solar radiation in Germany since 1991
Data: German Meteorological Service. © Fraunhofer ISE

9Agrivoltaics: Opportunities for Agriculture and the Energy Transition

2.3

Definition and potential of agrivoltaics

Agrivoltaics is a technology that allows land to be usedsimultaneously for farming and generating electricity withphotovoltaics[12]. This means that a field can be dual purpose:to grow crops (photosynthesis) and generate solar power(photovoltaics). Some PV modules that provide shelter toanimals are counted as agrivoltaics although their featuresare similar to those on a conventional PV roof.
The technical solutions for integrating PV into farming are
as diverse as farming itself. They can be broadly categorized
into open and closed systems (see figure 9). Closed systems
mainly cover PV greenhouses, while open agrivoltaic systems
can be broken down into ground-level, interspace PV andstilted, overhead PV. PV modules in overhead systems aremounted at least 2.1 meters above the ground (see section on
DIN SPEC 91434 on next page). With overhead systems, theland under the PV modules is used for farming, whereas withinterspace systems, it is usually the land between PV modules
that is farmed.

The main benefits of interspace systems are that they havelower costs and tend to impact the landscape less. Overhead
installations, on the other hand, use the land more efficiently
and can give crops greater protection against adverse
environmental effects. Certain interspace system concepts
can also provide protection against storm damage andexcessive evaporation.
Similar to ground-mounted PV systems, agrivoltaic systems
can be built either with a fixed mounting system or a single ordual-axis tilting construction (solar trackers). Tracking systems
allow for more flexible light management as their PV modules
can be tilted individually.
This guideline mainly looks at overhead PV systems in farming(> 2 m) and horticulture (approx. 2.5 m), including applications
for specialty crops such as those in viticulture and fruit andvegetable growing. It discusses ground-level, interspace
PV systems to a lesser extent and touches on their applications
in permanent grasslands and farming. The heights given here
for each of the applications should only be seen as a trend;
they serve to group the use cases from a technical andeconomic point of view. This guideline does not cover closed
systems such as PV greenhouses. Section 5 provides moredetailed information about the various technical solutions.

AGRIVOLTAICS

SystemExamplesClassification

Open

Interspace PV

Stilted, overhead

PV greenhouse

Opaquebuildings*

Fixed, single axis

Fixed, single axis,
dual axis

Fixed

Fixed

Structure
Typical PV module tilt tracking
Typical applications

Permanent
grassland

Arable farming

Horticulture

Aquaculture

Indoor farming*

Typical agricultural
products

Animal feed, meat

Staple foodFruit, vegetables

Fish, algae

Mushrooms*,
meat, dairy

GrazingAnnual crops

Perennials

Open pondaquaculture

Barns, stables*

HayingGrain,
oleaginous crops

Specialty crops

Closed pondaquaculture

Vertical farming*

Biodiversity PV*

Use of large
machinery

Orcharding,vineyards

Floating PV
aquaculture

Beekeeping*

Crop rotation

Protected
cultivation

Onshore, offshore

Typical crops
and agriculturalactivities*No agrivoltaic application in the strictest sense
Fig. 9: Classification of agrivoltaic systems© Fraunhofer ISE

10ClosedAgrivoltaics: Opportunities for Agriculture and the Energy Transition

Summary of DIN SPEC 91434: “Agri-photovoltaic
systems — Requirements for primary agricultural use”
Fraunhofer ISE and the University of Hohenheim have worked
with the German Institute for Standardization (DIN) anda consortium of partners in research and industry to develop
the standard DIN SPEC 91434. By outlining the requirements
for the primary agricultural use of agrivoltaics, the standard
aims to clearly distinguish agrivoltaic systems from conventional
ground-mounted systems, which is likely to be a key
prerequisite for ensuring agrivoltaic systems are successfully
brought to market. The DIN SPEC provides legislators, funding
bodies and regulatory authorities with a basis for testingand sets out quality criteria for constructing and operating
agrivoltaic systems. The DIN SPEC also aims to lay thegroundwork for the further development of a test method andthe possible certification of agrivoltaic systems.
15 institutions, mostly from the solar PV industry, participatedin the consortium that drew up the standard. The DIN SPEC
specifications mainly cover the agricultural aspects ofagrivoltaics as the relevant technical standards for solar PV
already exist and can therefore be adopted for this areaof application. Table 1 shows the key areas covered by the
DIN SPEC and how it categorizes agrivoltaic systems.
A core tenet that applies to all categories is that the land
used for agrivoltaics must continue to be used for agricultural
purposes. A more detailed description of the agriculturalactivities at each agrivoltaic area needs to be recorded inan agricultural cultivation proposal. The criteria and key
requirements for the agricultural cultivation proposal are:
The previous agricultural usability of the area shall bemaintained, and the planned form of land use shall be set
out in an agricultural usage proposal.
Land loss after installing the PV system must not exceed
10 percent of the total project area for category I and
15 percent for category II.
Light availability, light homogeneity and water availability
must be checked and adapted to the needs of the
agricultural products.
Steps should be taken to avoid soil erosion and damage
caused by PV system design, anchoring in the soil or thewater runoff from the PV modules.
It shall be ensured that the agricultural yield after
constructing the agrivoltaic system is at least 66 percent of
the reference yield. The reference yield is calculated using
the three-year average of yields from the same agriculturalland or using comparable data taken from the relevantpublications.
In addition to these key metrics and specifications, the
DIN SPEC lists further recommendations for designing andinstalling agrivoltaic systems effectively. The DIN SPEC canbe downloaded free of charge here: https://www.din.de/en/
wdc-beuth:din21:337886742

Table 01: Overview of categories and forms of land use as set out in DIN SPEC 91434
Agrivoltaic systems

Use

ExamplesCategory I:

1A: Permanent and perennial crops

Fruits, berries, viticulture, hops

Overhead PV with vertical clearance > 2.1 m

1B: Single-year and long-term crops

Arable crops, vegetables, alternating
grassland, fodder

Farming under the agrivoltaic system

1C: Permanent grassland with mowing

Intensive and extensive commercial
grassland(Image A)

1D: Permanent grassland with pasture

Permanent pasture, pasture rotation(e.g., cattle, poultry, sheep, pigs and goats)Category II:

2A: Permanent and perennial crops

Fruits, berries, viticulture, hops

Interspace PV with vertical clearance < 2.1 m

2B: Single-year and long-term crops

Arable crops, vegetables, alternating
grassland, fodder

Farming between the rows of agrivoltaic
systems

2C: Permanent grassland with mowing

Intensive and extensive commercial
grassland(Image B/C)

2D: Permanent grassland with pasture

Permanent pasture, pasture rotation(e.g., cattle, poultry, sheep, pigs and goats)11

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

A

B

AN
AL
AN
AL

C
LegendAL Cultivatable agricultural areas
AN Uncultivatable agricultural areas
h1 Clearance height below 2.10 m
h2 Clearance height above 2.10 m
1 Examples of PV modules
2 Mounting structure
3 Examples of crops

AN
AL

Fig. 10: Illustration of the categories and forms of land use as set out in DIN SPEC 91434 © Fraunhofer ISE
Image A: Illustration of a category I setup; Image B: Illustration of a category II setup, variant 1;
Image C: Illustration of a category II setup, variants 1 and 2.

Land use in Germany

Total area in Germany

Land used for agriculture
Animal feed andfoodstuffs 80 %Residential,
traffic, water,
miscellaneous
7.8 million ha
Land used for
agriculture
16.6 million ha
Forest area
11.4 million ha

Energy crops 13 %Industrial crops 2 %35.8 million ha
Other usage 5 %Fig. 11: Land use in Germany © Fachagentur Nachwachsende
Rohstoffe e. V. (2023)[13]12High potential
Out of all the applications for integrated PV, agrivoltaics holds
the greatest potential. This installed capacity would only
require approximately 4 % of Germany's available farmlands
to meet the country’s entire current electricity demand withoverhead agrivoltaic systems. Fraunhofer ISE conducted an
initial assessment to estimate the potential of agrivoltaics andfound that this was around 1700 GWp in Germany. It based its
estimates largely on shade-tolerant crops and those typicallyused in crop rotation. Even using just 10 percent of this1700 GWp capacity would almost triple Germany’s current
PV capacity. Interspace PV modules that are installed close
to the ground with wide gaps between rows allow crops tobe grown in the intervening strips. One hectare is needed
to generate 0.35 MWp, so growing fodder on permanent
grassland offers the potential to support another 1200 GWp
capacity. From the perspective of generating electricity, thedual use of agricultural land with agrivoltaics is considerably
more efficient than growing energy crops (e.g., it generates
32 times more power per hectare than growing maize asa biofuel). Energy crop cultivation takes up 13 percent ofagricultural land in Germany (see figure 11).

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

2.4

Research sites in Germany

There are at least eleven agrivoltaic systems in operation forresearch purposes in Germany. These are listed in table 2.
The key data and research questions for these locations aredetailed on the following pages along with summaries ofother research projects.

Table 02: Overview of agrivoltaic research sites in Germany to date
Installed
capacity

Year ofcommissioning

Tracking PV array

22 kWp2013

Vegetable growing

PV tubes

14 kWp2015

Heggelbach, Sigmaringen district,Baden-Württemberg

Arable farmingSouth-west facing,
fixed PV modules

194 kWp

2016

Gelsdorf, Ahrweiler district,
Rhineland-Palatinate

Fruit growing

Tracking and fixed semitransparent PV modules

258 kWp

2021

Alt-Morschenich, Düren district,
North Rhine-Westphalia

Farming/vegetable
growing

Tracking and fixed, with water
management

300 kWp

2021

Bavendorf, Baden-Württemberg

Fruit growing

Tracking and fixed PV modules

227 kWp

2022

Dresden-Pillnitz, Saxony

Arable farming

Vertical PV modules

134 kWp

2022

Heuchlingen, Heilbronn district,Baden-Württemberg

Fruit growing

Fixed PV modules

113 kWp

2023

Tuniberg, Munzingen,Baden-Württemberg

Viticulture

East-west aligned,
fixed PV modules

300 kWp

2023

Blankenhornsberg, Ihringen,Baden-Württemberg

Viticulture

Single-axis tracking andfixed PV modules

200 kWp

2023

Geisenheim,
Rheingau-Taunus district, Hesse

Viticulture

Single-axis tracking PV modules

94 kWp2023

Location

Type of land use

Technology

Weihenstephan/Freising, Bavaria

Vegetable growing

Weihenstephan/Freising, Bavaria

Weihenstephan 2013
Researchers at the Institute for Horticulture based in the
University of Weihenstephan-Triesdorf conducted the firstpreliminary tests on a small, dummy ground-mounted
PV system (south-facing) in 2011. They used roofing felt tosimulate the shade from PV modules and grew crops suchas lettuce underneath. Results showed that the differencesin shade and soil moisture caused considerable disparitiesin crop growth between the more/less shaded areas directly
under/north of the dummy PV modules, which would makeit unsuitable for real-world application. The first agrivoltaic
system with rows of east-west solar tracking PV modules(see figure 12) was constructed in 2013 as a way of preventing
excess shading on parts of the ground within the system.

13

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Mover deskPV module

Actuator< WestSteering unit
and inverter

East >
Barrier-free soil cultivation

Fig. 12: Cross-section view of the agrivoltaic system in Weihenstephan© 2020 B. Ehrmaier, M. Beck, U. Bodmer

Table 03: Damage to cabbage crops © 2020 B. Ehrmaier, M. Beck, U. Bodmer
Dense section of PV
module rows:
0 cm between
PV modules

Average weight of a headof Chinese cabbage grownwith agrivoltaic system(2014)

25 cm between
PV modules

66 cm between
PV modules

Grown without a PV system,
for comparison

1348 g1559 g1970 g2762 gAround 50 percent of theyield achieved without
agrivoltaics

Around 56 percent of theyield achieved without
agrivoltaics

Around 71 percent of theyield achieved without
agrivoltaics

Varying distances between PV modules within the rows aims tohelp determine how different amounts of shade affect the crop
yield and thereby identify the optimal row density. Tests with
Chinese cabbage showed 29 to 50 percent declines in yields.
The results differ depending on the amount of shade and areshown in table 3.
Soil compaction from constructing the PV system and damage
to crops positioned under the PV modules’ drip edge werepossible compounding factors explaining why crops in theagrivoltaic system produced reduced yields.
Technical data:
Area: 483 m²
Tracking: East-west; calendar controlled
PV modules: CSG 245 Wp (90 PV modules)
Installed capacity: 22 kWp
Use: Self-consumption

14

Weihenstephan 2015
Installing rain gutters on the drip edges of the PV modules of
the agrivoltaic system caused new problems, particularly in
winter. As an alternative, researchers examined how horizontal,
overhead tubular PV modules affected crop yields.
In 2015, the Weihenstephan-Triesdorf University of Applied
Sciences constructed a second German research site withthe company TubeSolar where researchers tested the viabilityof tube-shaped PV modules. This PV system has a capacityof 14 kWp, and potatoes and varieties of lettuce are grownunderneath. A test with lollo rosso lettuce showed that yields
for crops under the PV tubes were no more than 15 percent
lower than the yields achieved without the agrivoltaic system,
meaning such PV modules offer new opportunities foragrivoltaics in horticulture, at least for shade-sensitive crops.
For a comprehensive assessment, however, the LCOE needs
to be examined against the contribution margin from crop
production.

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Heggelbach 2016
The third agrivoltaics research site was constructed at the
Hofgemeinschaft Heggelbach farm near Lake Constance(Germany) in 2016 as part of the “APV-RESOLA” project.
This biodynamic mixed-farming business has been operating
for more than 30 years with 165 hectares of agricultural land.
Winter wheat, potatoes, celery and clover grass were planted
as test crops. Installing the bifacial double-glass PV modules
with five-meter ground clearance, south-west orientation anda larger gap between the rows of PV modules ensures that thecrops receive consistent amounts of sunlight. The clearance
height and distance between the supporting structures alsoenables the farmers to use large machinery, such as a combine
harvester, without any major restrictions. The rows are 9.5 m
apart with a row width of 3.4 m. The installed capacity of thistest system is enough to supply 62 four-person households
annually. Due to the increased distances between rows, thisinstalled capacity is around 25 percent lower per hectare
compared to conventional ground-mounted PV systems.

8m
5m

11.7

5m

18.4

m

Fig. 13: Illustration of the agrivoltaic system in Heggelbach© AGRISOLAR Europe GmbH

Results showed that the land-use rate rose to 160 percent
during the first year of the project (2017), demonstrating thepractical viability of agrivoltaics. The yields of crops grownunder PV modules remained over the critical 80 percent markcompared to reference areas without PV modules, allowing
them to be marketed as commercially viable.

Performance in kW

The agrivoltaic system generated 1266 kWh per installed kWp
in the first 12 months (September 2016–September 2017).

Feed-in from agrivoltaic system kW
Grid supply Heggelbach kW
Self-consumption Heggelbach kW

Hours
Fig. 14: The agrivoltaic system at Hofgemeinschaft Heggelbach enabled the farm to cover almost
all of its energy demand in summer 2017 using the power generated with the system © BayWa r.e.

15

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

This output is a third more than the average for Germany,
which is 950 kWh per kWp. One reason for this is the highsolar radiation in the region, while another is the additional
yields thanks to the bifacial PV modules. The electricity
generated over the day suits the farm’s load profile, meaningthat the farm consumes around 40 percent of the solar power
generated on site, such as for charging electric vehicles andprocessing agricultural products. The agrivoltaic system almost
covered the farm’s entire daily load in summer. Installinga battery storage device with 150 kWh capacity boosted thelevel of self-consumption to around 70 percent. Project partner
Elektrizitätswerke Schönau buys the surplus power.

potential of agrivoltaics in arid regions. Further tests will need
to be conducted in appropriate climate regions with additional
crops. The solar irradiance was 1319.7 kWh per square meterin 2018, an increase of 8.4 percent over the previous year. This
meant that solar power generation in the 2018 harvest year
rose by 2 percent to 249,857 kWh, resulting in an exceptionallyhigh specific yield of 1285.3 kWh per kWp. The outcomes ofthe Heggelbach pilot project suggest that agrivoltaics help
stabilize yields as crops benefit from the additional shade,especially during dry spells[5]. More information about the pilot’s
agricultural results is detailed in section 3.1. The “APV‑RESOLA”
project was successfully completed in 2021.

Yields during the 2018 summer heat waves significantly
exceeded the previous year’s results. The partial shade under
the PV modules increased crop yields while the high levels of
solar radiation increased solar power generation. This improved
land-use efficiency by 86 percent where the potato crops
were being tested. The crops were able to compensate forthe lack of rain in summer — possibly due to the additional
shade from the PV modules. This observation illustrates theTechnical data:

100 % potato cultivation and 100 % solar power generation

Area: 3400 m²
PV modules: bifacial double-glass PV modules, 270 Wp(720 PV modules)
Installed capacity: 194.4 kWp
Use: Self-consumption, feeding into grid

103 % potato cultivation and								83 % solar power generation

Fig. 15: The dual use of land for agrivoltaics and potato growing increased land-use
efficiency on the Heggelbach test site to 186 percent © Fraunhofer ISE

16° 186 % land-use efficiency

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Gelsdorf 2021
In the “APV-Obstbau” project, a pilot system with 258 kWp
capacity was installed at the Nachtwey organic fruit farm in
Gelsdorf (Ahrweiler district, Rhineland-Palatinate) in spring
2021. The research team used the agrivoltaic system on theorchard to look at light management, system design, landscapeesthetics, the system’s cost-effectiveness, its social acceptability
and the parameters of crop cultivation.
The project has four different pilot systems: (1) control fieldwith conventional hail-protection nets; (2) agrivoltaic system;(3) agrivoltaic system with reduced use of crop protection
product; and (4) sheet covering. The part of the project dealing
with public acceptance and social responsibility looks at
different possible areas of conflict (land use, distribution, fair
processes) in various stakeholder groups.
Technical data:
Area: 3552 m²
Tracking: 3 rows, single-axis
PV modules: semi-transparent double-glass PV modules,
225 Wp (1148 PV modules)
Installed capacity: 258 kWp
Use: Self-consumption, feeding into gridFig. 16: Agrivoltaic system at the Nachtwey organic fruit
farm (2021, 2023) © Fraunhofer ISE

Alt-Morschenich 2021
The agrivoltaic system was installed as part of the “AgriFEe”
project (formerly “APV 2.0”). Various solutions are
implemented in this system, such as bifacial tracking andnon‑tracking modules and different orientations (south-facingor east-west). This allows the various effects on growth andyield of the cultivated crops to be investigated. High-value
crops, fruit and vegetables are being cultivated in particular.
Research is also being conducted into innovative tracking
algorithms with a combined light simulation for PV and cropdevelopment and a smart irrigation system. In addition toagronomy and technical and economic considerations, issues
relating to social acceptance are also being investigated.

Technical data:
Area: 3766 m²
Tracking: East-west for some parts of the system, test
algorithms; static on two parts of the system
PV modules: bifacial PV modules, 370 Wp (810 PV modules)
Installed capacity: 300 kWp
Use: Phenotyping robots, irrigation system, buffer storage inbatteries

17

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Bavendorf 2022
At the Bavendorf site, the Kompetenzzentrum Obstbau
Bodensee (Competence Center for Fruit Production in the Lake
Constance Region) and Fraunhofer ISE are investigating theimpact of an agrivoltaic system on organic farming using four
different varieties of apple. The system comprises a static anda tracking section, as well as a reference area. Investigations
are focused on the extent to which changing the microclimate
under the PV modules could reduce the use of pesticides.

Heuchlingen 2023
The agrivoltaic system was constructed at the experimental
fruit farm of the State Education and Research Institute for
Viticulture and Pomology in Heuchlingen. It is intended to cover
over soft fruits and strawberries and have a positive impact
on the microclimate through its closed design. Thanks to theroof structure with drainage system, it is possible to collect andstore rainwater all year round and use it for irrigation purposes.
In addition, a circulating water management system is intended
to prevent nitrate leaching.

Technical data:
Technical data:
Area: 5000 m²
Tracking: single-axis tracking with east-west orientation(central part of system), fixed mounting structure(northern part of system)
PV modules: semi-transparent double-glass PV modules,
300 Wp (756 PV modules)
Installed capacity: 227 kWp
Use: 100 percent fed into the grid

Dresden-Pillnitz 2022
In 2022, the University of Applied Sciences Dresdenconstructed an agrivoltaic system with vertical modules at theDresden-Pillnitz site using grants from the State of Saxony.
The system is used for research and student education
purposes. Investigations are primarily focused on issues
relating to agricultural production and the environment. The
topics covered include the factors influencing crop yields, themicroclimate in the system, groundwater and evaporation,
insect protection and the development of the agricultural
technology used in agrivoltaic systems.
Technical data:
Area: 4500 m2
PV modules: bifacial double-glass PV modules, 430 Wp(320 PV modules)
Installed capacity: 134.4 kWp
Use: electric (autonomous) vehicles, machinery andequipment, feeding into the grid18

Area: 2000 m²
PV modules: semi-transparent double-glass PV modules,
200 Wp (384 PV modules)
Installed capacity: 113 kWp
Use: partly self-consumption

Tuniberg 2023, Blankenhornsberg 2023
and Geisenheim 2023
The effects of climate change are becoming apparent inviticulture and are causing crop losses, e.g., due to heatdamage, heavy rain, hail and late frosts. The PV systems(also known as viti-PV) installed directly over the vines atthe sites in Tuniberg, Blankenhornsberg and Geisenheim
are intended to protect the vines, delay grape ripening andprovide a more consistent climate in general so that crop
losses can be prevented. It is not just the crops but also theindividual PV modules that benefit from the synergy, as they
can be cooled by the high position and water evaporation(transpiration) of the crops. The combination of moreconsistent crop yields and additional income from the sale ofelectricity gives the farmer greater financial security, even intimes of increasing extreme weather events.
Technical data for Tuniberg:
Area: 5000 m2
PV modules: semi-transparent PV modules, 220 Wp(1577 PV modules)
Installed capacity: 300 kWp
Use: 100 percent fed into the grid

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Technical data for Blankenhornsberg 2023:
Area: 1400 m2
Tracking: single-axis tracking (rows running east-west)
for one part of the system
PV modules: semi-transparent double-glass PV modules,
550 Wp (78 PV modules), 415 Wp (200 PV modules), 300 Wp(474 PV modules)
Installed capacity: 268 kWp
Use: 100 percent fed into the gridTechnical data for Geisenheim 2023:
Area: 1650 m2
Tracking: single-axis tracking with east-west orientation
PV modules: semi-transparent double-glass PV modules,
170 Wp (550 PV modules)
Installed capacity: 94 kWp
Use: primarily self-consumption, feeding into gridFig. 17: Agrivoltaic system in Blankenhornsberg, 2023

Fig. 18: Agrivoltaic system in Geisenheim© Jona Pillatzke, WBI© HS Geisenheim

19Agrivoltaics: Opportunities for Agriculture and the Energy Transition

2.5

Operational sites in Germany

In addition to the following descriptions of operational systems,
there are other agrivoltaic systems in Germany that are
implemented or planned.
Table 04: Overview of specified operational systems and certain other operational systems in Germany
Location

Type of land use

Technology

Installed
capacity

Year ofcommissioning

Warmsried, Bavaria

Arable farming, vegetable
growing, livestock farming

Fixed PV arrays

70 kWp2008

Eppelborn-Dirmingen, Saarland

Fodder

Vertical PV modules

2000 kWp

2018

Büren-Steinbach,North Rhine-Westphalia

Berry bushes, fruits

Tracking PV modules

740 kWp

2020

Aasen, Donaueschingen,Baden-Württemberg

Animal feed, farming

Vertical PV modules

4100 kWp

2020

Althegnenberg, BavariaCorn, oats, spelt, clover

Single-axis tracking PV modules

1890 kWp

2020

Lüptitz, Saxony

Livestock farming,
vegetable growing

Single-axis tracking PV modules

1045 kWp

2021

Kressbronn am Bodensee,
Baden-Württemberg

Fruit

Fixed PV modules

239 kWp

2022

Merzig-Wellingen, Saarland

Arable farming

Vertical PV modules

5200 kWp

2023

Fig. 19: Module row with bifacial
PV modules on the agrivoltaic
system in Heggelbach© Fraunhofer ISE

20

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Büren-Steinbach 2020
Farmers Fabian Karthaus and Josef Kneer began constructing
an operational agrivoltaic system at their organic soft fruit
farm in Büren (North Rhine-Westphalia) in 2019. They applied
for a building permit to construct the system, classifying it
as a greenhouse for specialty crops, and it was approved asa special project in line with section 35 BauGB.
The mounting system was built in the “venlo” greenhouse styleand comprises a total of 20 gabled roofs. The structure is madefrom steel and aluminum profiles. The mounting system isembedded in the ground using driven piles. The spacing in thesystem (3.5 m x 4.2 m) and a clearance height of 3.2 m enable
the farmers to use standard agricultural machinery to maintaintheir crops. The actual roof is made of the bifacial PV modules.
They generate electricity and protect the crops underneathfrom the sun and the elements. The cabling runs only in theroof construction to ensure that the farmers can work on theland under the PV modules without any problems.

Community solar park, Aasen, Donaueschingen 2020
Next2Sun constructed a vertical agrivoltaic system near
Aasen, north of Donaueschingen, in partnership withthe energy cooperative Solverde Bürgerkraftwerke
Energiegenossenschaft eG as its operator. The system
has a capacity of around 4.1 MWp and can supply power
to 1400 homes [15]. As part of the project, arable land wasconverted into extensively farmed grassland. The overall shareof land taken up by the module rows is minimal with a 10 m
gap between rows, allowing the land in between to be farmed.
Technical data:
Area: 140,000 m²
PV modules: bifacial double-glass PV modules, 370–380 Wp(10,960 PV modules)
Installed capacity: 4100 kWp
Use: 100 percent fed into the gridBeneath the installation, blueberries, raspberries and apples areplanted in ridges around the supporting structure, with eachroof apex covering a ridge. A sensor-supported drip irrigation
system regulates the watering of the ridges. The wateringsystem takes into account the current temperature, the wind,
sun intensity and the forecast rainfall. The drip edge foreach roof panel is positioned between each ridge. Rainwater
infiltrates the facility and is captured in drains where it is thenprepared for reuse.
The farmers report that they were impressed by the highblueberry yields in the first few years. They recorded slightly
lower strawberry yields in the first year. There has not been any
yield information regarding the apples and grapes yet.
Technical data:
Area: 4200 m²
PV modules: bifacial PV modules, special production,
320 Wp (2320 PV modules)
Installed capacity: 740 kWp
Use: 50 percent self-consumption, 50 percent fed into the
gridFig. 20: Vertical agrivoltaic system in Aasen, Donaueschingen© Solverde Bürgerkraftwerke

21Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Community solar park, Lüptitz 2021
Solverde Bürgerkraftwerke Energiegenossenschaft eG also
operates another agrivoltaic system in Lüptitz near Leipzig.
This involved dismantling an existing ground-mounted
PV system and replacing it with a more efficient, moreadvanced interspace PV system. Data from the operator
shows that the “Repowering Lüptitz” project is profitable
despite the costs to dismantle the first system. The PV system
was constructed in a commercial area and put into operationin June 2021.

Merzig-Wellingen 2023
The vertical agrivoltaic system in Merzig-Wellingen comprises
an operational system as well as a research area, which isthe focus of the “VAckerPower” and “VAckerBio” research
projects. The entire area is used for farming. The purpose of
the investigations is to complete a comprehensive analysis oftechnical issues and agronomy considerations. The use of theresearch area for farming purposes is supplemented by the useof the maintenance strips under the PV modules for biodiversity
measures and the performance is analyzed.

Technical data:

Technical data:

Area: 16,500 m²
PV modules: bifacial PV modules, 415 Wp (2520 PV modules)
Installed capacity: 1045.80 kWp
Use: 100 percent fed into the grid
Kressbronn 2022
The agrivoltaic system in Kressbronn am Bodensee is the firstsuch system to be constructed, inaugurated and connected to
the grid as part of the “Model Region Agri-PV BaWü” project.
It is also Germany’s first electricity-generating system in thefield of apple cultivation to be integrated into a plantation witha full harvest (Obsthof Bernhard). The system offers varying
shading of modules with two transparency levels (51 and40 percent); the effects of these on the ecophysiology of theapples will also be investigated, along with potential effects ofpesticides on the PV modules.
Technical data:
Area: 4000 m²
PV modules: Type 1: semi-transparent double-glass PV
modules,170 Wp (552 PV modules); type 2: semi-transparent
double-glass PV modules, 260 Wp (469 PV modules)
Installed capacity: 239 kWp
Use: 100 percent fed into the grid

22

Area: 140,000 m², of which 17,000 m² research area
PV modules: bifacial PV modules 420–460 Wp
Installed capacity: 5200 kWp, of which 500 kWp on the
research area
Use: 100 percent fed into the grid

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

2.6

Research projects in Germany

Table 05: Overview of some research projects in Germany
Project

Duration

APV-Obstbau April 1, 2020
(Orcharding) to March 1,
2025

ClientProject partners

BMEL*1,MKUEM*2

Nachtwey organic fruit farm,
BayWa r.e. Solar Projects GmbH, DLR-RLP*11,
EWS*12, Vertriebs GmbH, AGCO GmbH*13,
Fraunhofer ISE
Fraunhofer IMW*14, DBFZ*15,
Stiftung Kulturlandschaft Sachsen-Anhalt,
UFZ*16Agri4PowerMay 1, 2020
BMWK*3to June 30, 2021

Landgewinn

September 1,
2021
to August 31,
2024
January 1, 2022
to December 31,
2026

AgriFEe

More information
https://s.fhg.de/Orcharding

https://s.fhg.de/Agri4PowerGER

BMWK,
Projektträger
JülichOffenburg University of Applied Sciences,
Fraunhofer ISE, KIAF*17, IÖW*18

https://s.fhg.de/LandgewinnGER

BMBF*4

Forschungszentrum Jülich, Fraunhofer ISE

https://s.fhg.de/AgriFEe20EN

Model
RegionAgri‑PV
BaWü

January 1, 2022
to November 1,
2024

MLR*5, UM
BW*6

Kehl University of Applied Sciences, LVWO*19,
LTZ*20, KOB*21, Obsthof Bernhard, RWB*22,
Obsthof Vollmer, Fraunhofer ISE

https://s.fhg.de/ModelregionEN

SynAgri-PV

July 1, 2022
to June 1, 2025

BMBF*4

ZALF*23, University of Hohenheim,
Elysium Solar GmbH, BBH PartGmbB*24,
Stiftung Umweltenergierecht,
Bosch und Partner GmbH, Fabian Karthaus,
Hofgemeinschaft Heggelbach, Fraunhofer ISE
Next2Sun Technology GmbH, Fraunhofer ISE

https://s.fhg.de/SynAgriPVEN

University of Hohenheim,
Next2Sun Technology GmbH, Fraunhofer ISE

https://s.fhg.de/VAckerBioENG

VAckerPower November 1,
2022
to October 1,
2025

BMWK

https://s.fhg.de/VAckerPowerEN

VAckerBio

October 1, 2022 DBU*7
to September 1,
2023

VitiVoltaic

July 1, 2020
ERDF*8,Hochschule Geisenheim University
to June 30, 2025 ERDF‑REACT*9,HMUKLV*10

https://s.fhg.de/VitvoltaicEN

VitiCult-

January 1, 2023
to December 1,
2025

sbp sonne GmbH*25,
Hochschule Geisenheim University,
Fraunhofer ISE

https://s.fhg.de/VitvcultEN

WFG*26, ZG Raiffeisen eG,
ZG Raiffeisen Technik GmbH,
Intech GmbH & Co. KG, HEG*27,
Sick AG, WBI*28, KIAF, Fraunhofer ISE,
BürgerenergieKaiserstuhl, etc.

https://s.fhg.de/Weinbau40GER

PVmobil
Weinbau 4.0

BMBF

May 15, 2023
MLR, ERDF
to December 31,
2027*1 	German Federal Ministry for Food and Agriculture(BMEL)*2 	Ministry for Climate Protection, Environment, Energy
and Mobility of the State of Rhineland-Palatinate(MKUEM)*3 	German Federal Ministry for Economic Affairs andClimate Action (BMKW)*4 	German Federal Ministry of Education and Research(BMBF)*5 	Ministry of Food, Rural Affairs and Consumer
Protection Baden-Württemberg (MLR)*6 	Ministry of the Environment, Climate Protection andthe Energy Sector Baden-Württemberg (MU BW)*7 	German Federal Environmental Foundation (DBU)*8 	European Regional Development Fund (ERDF)*9 	Recovery Assistance for Cohesion and the Territories
of Europe (REACT)*10 	Hessian Ministry of the Environment, Climate
Protection, Agriculture and Consumer Protection(HMUKLV)*11 	Center for Rural Services, Rheinpfalz Region(DLR RLP)*12 	Elektrizitätswerke Schönau (EWS)*13 	Allies-Gleaner Cooperation (AGCO GmbH)*14 	Fraunhofer Center for International Management
and Knowledge Economy IMW*15 	Deutsches Biomasseforschungszentrum gGmbH(DBFZ)*16 	Helmholtz-Zentrum für Umweltforschung GmbH
(UFZ)
*17 	Kehl Institute for Applied Research (KIAF)*18 	Institute for Ecological Economic Research (IÖW)*19 	State Education and Research Institute for Viticulture
and Pomology (LVWO)*20 	Center for Agricultural Technology Augustenberg(LTZ)*21 	Competence Center for Fruit Production in the Lake
Constance Region (KOB)*22 	Regionalwerk Bodensee (RWB)*23 	Leibniz Centre for Agricultural Landscape Research(ZALF)*24 	Becker Büttner Held Rechtsanwälte Wirtschaftsprüfer Steuerberater PartGmbB*25 	Schlaich bergermann partner — sbp sonne GmbH
*26 	Wirtschaftsförderung des Landkreises Emmendingen
mbH (WFG)*27 	Heidelberger Energiegenossenschaft eG (HEG)*28 	State Institute of Viticulture Freiburg (WBI)

23

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

APV-Obstbau (Orcharding)Fraunhofer ISE joined its partners in research and industry forthe “APV-Obstbau” (Agrivoltaic Orcharding) project, where
they examined the extent to which agrivoltaic systems canreplace nets and sheets to protect apple orchards from hail,
which system design would be most useful and how much the
PV system affects harvest yields.
Agri4Power
Researchers at Fraunhofer IMW ran the “Agri4Power”
project between 2020 and 2021. The project looked at how
sustainable synergies could be created by combining vertical,
bifacial solar PV systems with flower strips, which foster
biodiversity, alongside agricultural production at the sametime. They examined the economic and environmental aspects,
as well as questions of social acceptance.[14]Landgewinn
The three-year joint project “Landgewinn” is researching the
agricultural sector by carrying out an energy system analysis.
The team includes the Energy Systems and Energy Economy
research group and the Photovoltaic Technology and Biochar
research group from the Institute of Sustainable Energy
Systems at Offenburg University of Applied Sciences, as well
as Fraunhofer ISE, Kehl University of Applied Sciences and theInstitute for Ecological Economic Research (IÖW).
As part of this research project, the team is generating
a comprehensive analysis of three decarbonization technologies
in order to implement an energy system analysis. This aims
to highlight the available potential and the range of actions
that could be taken to reduce CO2 in agriculture. In addition
to pyrolysis for producing biochar and the decarbonization offarming machinery, Fraunhofer ISE is focusing on investigating
agrivoltaic technology from an economic and ecologicalperspective. Kehl University of Applied Sciences is also
investigating the legal framework.
The motivation behind the project partners’ work is toharmonize the energy supply and emissions in the agricultural
sector with energy and climate goals in the medium and longterm. Many agricultural businesses — as well as the German
agricultural sector in general — are under increasing pressure
since emissions and energy consumption in the agricultural
sector have remained at the same level for many years. The
purpose of an integrated assessment of the agriculture andenergy sectors as part of the energy system analysis is to open
up new opportunities for achieving energy and climate goals.
The project will incorporate technologies such as agriculturale-mobility, the transition to flexible electricity demand or
agroforestry systems.

24

AgriFEe
The “Coupling of photovoltaics and crop production” project(“AgriFEe,” formerly “APV 2.0”), led by Forschungszentrum
Jülich, has been further developing linked radiation andsimulation models, allowing both PV and crop production to
be optimized together. To assess how this affects the crops,
researchers are developing and deploying an in-situ phenotypicmonitoring system to collect and analyze quantitative
phenotypic data about the crops. They are also developing
innovative tracking algorithms, rainwater collection systems
and smart irrigation strategies. The test system was constructedin December 2021 in Morschenich-Alt, Germany.
Model Region Agri-PV Baden-Württemberg
The first implementation phase of the “Model Region
Agri-PV Baden-Württemberg” project aims to drive theexpansion of agrivoltaic technology in Baden-Württemberg.
The 13 project partners, including Fraunhofer ISE, intend to
focus their research on pomaceous fruits and berries in the first
implementation phase. Agrivoltaic systems with a total capacityof up to 1700 kWp are being constructed at five locations in
Baden-Württemberg. Three of these systems were successfully
installed in Kressbronn, Bavendorf and Heuchlingen in 2022.
In order to network the projects and make use of synergies,
a framework program has been established and is being
jointly managed by Kehl University of Applied Sciences andFraunhofer ISE. The program looks at a range of issues relating
to the implementation potential at other sites, as well asother research topics such as crop-specific system design anda more differentiated approach to the legal framework. The
agricultural investigations are being conducted by the Center
for Agricultural Technology Augustenberg, the CompetenceCenter for Fruit Production in the Lake Constance Region and
the State Education and Research Institute for Viticulture andPomology. The project is being funded by the Ministry of theEnvironment, Climate Protection and the Energy Sector as wellas the Ministry of Food, Rural Affairs and Consumer Protection
Baden-Württemberg.

Fig. 21: Agrivoltaic system in Kressbronn (2022)© Fraunhofer ISE

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

SynAgri-PV
The research project “Synergetic Integration of Photovoltaics
in Agriculture as a Contribution to a Successful Energy
Transition — Networking and Accompanying the Market
Take‑off of Agrivoltaics in Germany” (“SynAgri-PV”) was
launched in July 2022 with a project duration of three years
and is being funded by the German Federal Ministry of
Education and Research (BMBF).
The overarching goal of the project is to describe and assess
the central technical, legal, economic and social conditions
and requirements for establishing agrivoltaics in the Germanmarket and to develop proposals relating to the widespread
establishment of agrivoltaics. Under the coordination of
Fraunhofer ISE and the Leibniz Centre for AgriculturalLandscape Research (ZALF), the market launch of agrivoltaics
in Germany is being accompanied by project partners the
University of Hohenheim, Kanzlei Becker Büttner Held, Stiftung
Umweltenergierecht, Elysium Solar GmbH and Bosch & Partner
GmbH from an interdisciplinary and academic perspective. This
involves evaluating data from existing agrivoltaic systems acrossGermany, with the two associated farms — Fabian Karthaus
near Paderborn and Hofgemeinschaft Heggelbach by Lake
Constance — gaining experience of using the prototypes inpractice and incorporating this directly into the project.
The goal is to develop social objectives relating to the
expansion of agrivoltaics in Germany, specify the actions
required for implementation, propose some potential solutions
and identify additional fields of research. This will be achievedby taking an evidence-based approach and involving as manyof the relevant parties as possible. The project will involve
developing participation models i.e. participation models,evaluating the findings and making them accessible to thewider public and to policymakers.

VAcker projects
The “VAckerPower” and “VAckerBio” projects involve extensive
investigations into vertical, bifacial agrivoltaic systems in farming.
The combination of the two projects enables a comprehensive
analysis to be made of the vertical approach in farming,
both in relation to agriculture and to photovoltaic operation.
The aim of the “VAckerPower” project is to investigate theimpact of the vertical agrivoltaic system on land use forfarming purposes. The project is accompanying the initial
implementation of the vertical systems in a farming context
in Germany from a technical perspective. At the same time,
the project will investigate the operational reliability of thesystems, including under operational conditions (soiling,use of pesticides and fertilizers, etc.), and identify potential
for optimization. It will also consider social acceptance andsustainability aspects of these and other systems in a farming
context. Ultimately, the project will identify appropriate
locations through a potential study.
The “VAckerBio” project focuses on the influence of theagrivoltaic system on land use for farming purposes andon biodiversity. In order to investigate the development ofcrop cultivation, a microclimate monitoring system will be
implemented and soil quality and crop growth will be observed.
Usage concepts that promote biodiversity on uncultivatedstrips of land under the PV modules will also be developedand implemented. An important part of the investigations
will take place on the testing area of the agrivoltaic system
in Merzig-Wellingen.
VitiVoltaic
This project at Hochschule Geisenheim University aims to findout whether PV modules can alleviate the effects of climatechange on viticulture. The agrivoltaic system for the research
project was constructed in 2022 in Geisenheim. The projectis being funded by the European Regional Development Fund(ERDF) (“APV-Weinbau4Real”), ERDF-REACT (equipment) andthe Hessian Ministry of the Environment, Climate Protection,
Agriculture and Consumer Protection (“VitiVoltaic4Future”).

Fig. 22: Vertical agrivoltaic system in Merzig-Wellingen, 2023
© University of Hohenheim

25Agrivoltaics: Opportunities for Agriculture and the Energy Transition

VitiCult-PVmobil
This project aims to develop a mobile agrivoltaic system foryoung vines. The project partners are sbp Sonne, Fraunhofer
ISE and Hochschule Geisenheim University. The goal is todevelop a flexible system that can be adapted to the needsof winegrowers. Young vines require special protection.
The investigations are focused on the extent to which thissystem can be implemented from a technical and economic
perspective and the agronomic impact. A prototype is being
developed as part of the research project. The German Federal
Ministry of Education and Research (BMBF) is funding the
project.
Weinbau 4.0
The RegioWIN project “Weinbau 4.0” (“Viticulture 4.0”)
includes two sub-projects: “Agri-PV im Weinbau” (“Agrivoltaics
in Viticulture”) in Oberkirch and Ihringen-Blankenhornsberg
and “Agri-PV im Weinbau / Bürger-Viti-PV” (“Agrivoltaics
in Viticulture / Citizens’ Viticulture PV) in Riegel. The State
Institute of Viticulture Freiburg aims to investigate the impactof agrivoltaics on viticulture in the Southern Upper Rhine-High
Rhine region. “Weinbau 4.0” is a flagship project that wasawarded a prize as part of the state competition RegioWIN
2030 (“Regional Competitiveness through Innovationand Sustainability”). It is being funded by grants from
Baden‑Württemberg and the European Regional Development
Fund (ERDF).
The project focuses on the technical implementation ofagrivoltaics in viticulture as well as on investigating vines asa partner crop. The first step is to address issues relating tovine development and the extent to which agrivoltaics protect
the vines, as well as to clarify the cultivation options. It is also
seeking to answer questions relating to yields as well as grape
and wine quality. The cooperation partners include IntechGmbH & Co. KG, HEG Heidelberger EnergiegenossenschafteG and the Wirtschaftsförderungsgesellschaft des Landkreises
Emmendingen mbH as the project contact for “Weinbau
4.0.” Project partners such as the State Institute of Viticulture
Freiburg, the Kehl Institute for Applied Research (KIAF) and
Fraunhofer ISE are also involved.
The impact of agrivoltaics on viticulture is being investigatedat three sites in and around Freiburg: Blankenhornsberg,
Riegel and Oberkirch. The pilot system in Riegel is still in thedevelopment phase.

2.7International development

With over 14 GWp of installed agrivoltaic capacity worldwide(as estimated by Fraunhofer ISE), China has the largest share of
installed capacity with 12 GWp (as of July 2021). The country
also has the world’s largest agrivoltaic facility on the edgesof the Gobi Desert. Its PV modules have an installed capacityof 700 MWp, and berries are grown underneath them. Thisfacility also helps to combat desertification. Japan and South
Korea are two more countries in Asia that have identified theopportunities offered by agrivoltaics. However, they both use
smaller PV systems. At present, Japan has over 3000 systems.
In South Korea, where there is a huge migration away fromrural areas to urban areas, the government is planning to build
100,000 agrivoltaic systems on farms as a form of retirement
provision for farmers (selling electricity can earn them a monthly
income of around 1000 US dollars) and to combat the decline
in farming.
Agrivoltaics has multiple uses, so it can bring major benefitsto (semi) arid areas in emerging and developing countries thatreceive a high level of solar radiation. In addition to protecting
crops and livestock from the sun, agrivoltaic systems also provide
power to collect and treat water, which can stem desertificationand soil degradation trends. In combination this is a very
appealing prospect for future, agrivoltaics could help crops togrow in areas with dry, hot climates and high levels of solar
radiation, conditions in which they would otherwise not grow.
Generating power locally is another benefit of agrivoltaics forvillages that are usually far away from centralized grids. This
technology could give people access to education, information(e.g., by allowing them to charge radio and cellphone batteries)
and improved medical care (e.g., by powering refrigeration for
vaccines and medicines) and enable them to tap new sourcesof income. This also reduces rural populations’ reliance on fossil
fuels, such as diesel for generators. Electricity generated fromagrivoltaics can also go straight into powering refrigerationand processing equipment for the agricultural products. This
gives them a longer shelf life, makes them more marketable
and allows farmers to continue selling them beyond the harvest
season, which in turn brings higher revenues. Many countries
still face political and economic barriers to realizing the huge
potential for development cooperation. Political instability andlimited capital reserves in particular make technology transferdifficult and hinder long-term investment in agrivoltaics.
A preliminary study conducted by Fraunhofer ISE at a site
in the Indian state of Maharashtra suggests that shade andreduced evaporation under agrivoltaic systems can lead to up
to 40 percent yield increase of tomatoes and cotton[16]. In thisparticular case, Fraunhofer ISE researchers expect the land-use
efficiency for this region to double.

26

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

As part of the EU’s Horizon 2020 program, Fraunhofer ISE
worked with partners in Algeria on the “WATERMED 4.0”
project to find out how agrivoltaics impact the water regime.
In addition to reduced evaporation and lower air and soil
temperatures, using PV modules to harvest rainwater also plays
a role here. This rainwater collection is an appealing prospectfor many countries, including parts of Germany, especially inview of the increasing frequency of dry spells [17].

2.7.1

Chile

An agrivoltaics project in cooperation with Fraunhofer Chile,which was completed in spring 2018, saw three systems
with 13 kWp capacity constructed in areas surrounding
Santiago city, in the municipalities of El Monte, Curacaví andLampa. This region has high annual solar radiation and low
precipitation levels. An ongoing drought in what is alreadya dry and sunny climate has reduced precipitation by 20 to40 percent over the last ten years. These climatic conditions
have led farmers to actively seek out shade-giving installations
to help stop their crops from drying out and becoming
sunburned. This is where the use of agrivoltaics offers major
potential for synergies.
This project was backed by the local government, and its
participants researched which crops could benefit fromhaving slightly less solar radiation. The participating farms had
different profiles. One farm that grew broccoli and cauliflower
used the solar power generated by the agrivoltaic systemfor post-harvest processes, such as cleaning, packing andrefrigeration. Another pilot system was set up by a familyrun business specializing in herb growing. A third PV system
was constructed in a remote area with poorly developed
infrastructure and an unreliable power supply, providing sevenfamilies there with a secure supply.
These three sites in Chile are the first of their kind in Latin
America. The researchers looked at how agrivoltaics could be
adapted to suit the climatic and economic conditions in theregion and optimized overall. Due to initial positive results,
there are plans to build on this research by Fraunhofer Chile
with the support of local government. Researchers continue
to monitor the three pilot systems in field operation [18].
Fig. 23: Pilot PV systems in Curacaví and Lampa where
the Fraunhofer Chile Research Institute is investigating
which crops benefit from slightly less solar radiation© Fraunhofer Chile

27

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

2.7.2

FranceThere have been separate tenders for agrivoltaics in France
since 2017, and there are plans for 15 MWp of installedcapacity per year. Contracts are awarded partly based on theoffered price and partly based on how innovative the project is.
The maximum project size is 3 MWp of installed capacity. Only
greenhouse projects won tenders in the first tendering roundin 2017. In the second and third rounds, tenders for 140 MWp
each are awarded for systems with a capacity between
100 kWp and 3 MWp.
Successful projects are guaranteed a feed-in tariff over 20 years.
In March 2020, 40 MWp was secured for agrivoltaic projects,
especially for systems with solar tracking PV modules. Europe’s
largest PV facility with solar tracking PV modules to date wasconstructed at a vineyard in Tresserre (Pyrénées-Orientales,
Occitania) in 2018.
However, there are problems with the acceptance ofagrivoltaics in France. The first round of tendering did not
clearly outline the criteria for agrivoltaics, so some projects
have little to no agricultural production. This kind of
bandwagon effect from the PV industry has caused someresistance to agrivoltaics, especially in the agricultural sector
in France. In 2022, the French Environment and Energy
Management Agency (Agence de l’environnement et de lamaîtrise de l’énergie, ADEME) published a classification for
agrivoltaics (“Caractériser les projets photovoltaïques sur
terrains agricoles et l‘agrivoltaïsme”).

Fig. 24: Study with various types of lettuce at the agrivoltaics
research site run by the University of Montpellier in France© INRAE / Christian Dupraz

2.7.3

USA

An agrivoltaics research site in Massachusetts has successfully
demonstrated dual land use for growing crops and generating
electricity. On the back of this project, the state beganproviding funding for dual use solutions in 2018. This financial
support comes with specific requirements, stipulating that it is
only awarded to PV systems that are built on agricultural landand do not exceed 2 MW. The bottom edge of the PV modules
must be at least 2.4 meters high when installed in fixed rows;
this must be at least 3 meters in the case of systems withmodule tracking. In addition, no point in the field can be morethan 50 percent shaded during the main cultivation season[5].
The US Department of Agriculture also provides funding forsolar PV systems in rural areas as part of the Rural Energy
Advancement Program (REAP).
Arizona, Colorado, Indiana and Oregon are also home
to agrivoltaic facilities. Systems that focus on promoting
biodiversity rather than agricultural use are particularly popular.
Several universities and research institutions are working on
developing sustainable business models to make agrivoltaic
systems with an emphasis on agricultural use more attractive.

2.7.4

Mali and The Gambia

Mali and The Gambia are two of the world’s hardest hit
regions when it comes to the climate crisis. Extreme weather
events such as droughts will occur more frequently in future.
The “APV-MaGa” research project aims to improve food andenergy security and strengthen the stability of the agricultural
sector in the two countries by examining the extent to which
agrivoltaic systems with integrated rainwater collection canboost agricultural resilience.
The international consortium comprising Mali, The Gambia
and Germany brings together R&D activities in agronomics,socioeconomics and solar energy. It aims to demonstrate
the challenges and opportunities presented by agrivoltaics
and develop a deeper understanding of the synergies andinterrelationships at the water-energy-food nexus. The project
also looks at the socioeconomic aspect of this technology andseeks to promote the sustainable development of rural areas in
the partner countries.

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

2.7.5

TurkeyThe goal of the “SusMedHouse” project is to improve theproductivity, cultivation efficiency and agricultural sustainabilityof greenhouses in the Mediterranean region. The greenhouse
is located in Ankara and comprises several areas in which
the effects of innovative cultivation methods on agricultural
productivity are investigated.
The project is made up of the following components: artificial
intelligence to optimize processes, early detection of anomalies
and economic forecasting, decision support system (DSS) thatuses a mobile app to provide support when implementing therequired measures, integrated pest and pathogen management(IPPM) to guarantee food safety and reduce the use of chemicalfertilizers, development of biodegradable growth media fromcircular waste streams to increase eco-friendliness, optimizationof sunlight and lighting using a special greenhouse material
coating (sun protection with lower emissions), an agrivoltaic
system to protect crops and generate PV energy and thedevelopment of biosensors to analyze water quality.
Fraunhofer ISE is responsible for light management in thegreenhouses. The PV system has been designed so that it
can be integrated into an existing greenhouse. This design
puts the focus on the needs of the crops. The effects ofdesign parameters such as PV coverage, PV arrangement andgreenhouse orientation on light availability and distribution
have been investigated. A pilot greenhouse was constructed
and put into operation in July 2022. The PV pilot greenhouse
is being used to test tomatoes, bell peppers and lettuces.

Fig. 25: PV greenhouse © Fraunhofer ISE

29

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

3

Agriculture

Extreme weather events over the last few years have shownthat global warming is not an abstract threat — it is alreadyhaving a major impact on Germany’s agriculture. Springtime
precipitation is particularly crucial for crop growth, and it has
decreased significantly over the last 30 years[19]. Extra irrigation
can make up for these dry spells and protect yields. However,many places have restrictions on drawing ground and surface
water, therefore more options for adaptation need to befound. Drought is not the only extreme weather event tothreaten crops — hail, strong winds and heavy rainfall can also
harm crop growth.
Farms are increasingly using crop protection measures to copewith challenges posed by climate change, water conservationand the demand to counteract yield losses. Such measures
include growing crops in greenhouses and polytunnels andusing anti-hail netting in orchards. Anti-frost and anti-hailprotection measures are used especially for high-value specialty
crops and range from heating cables, anti-frost candles andstatic gas and oil burners to helicopters and cloud seeders that
disperse fine particles of silver iodide under the cloud base.
These technical and mechanical crop protection measures are
expected to grow in importance over the next few decades asclimate change impacts agriculture more and more.

The dual use of agricultural land for growing food andgenerating solar power gives farmers the opportunity toaddress many of these problems at the same time. Agrivoltaics
offers farms the option to diversify their income and maketheir internal processes circular. Reduced evaporation rates andprotection against hail and frost are also key aspects. Moreprotection systems can be integrated in a cost-effective manner
if farms harness existing structures, boosting productivity andadding value to agricultural land.
Using agrivoltaics does, however, present challenges for
agricultural production, including changing light conditions anddifficulty in tending crops due to the system’s structures. In thiscase, the right crops and a suitable system design should bechosen to minimize the risks and optimize synergies.

Fig. 26: Crops from the research site in Heggelbach (celery, potatoes,
wheat and clover grass) © University of Hohenheim/Andrea Bauerle

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

3.1

Results from the APV-RESOLA
research projectAs part of the APV-RESOLA research project, a sequence ofseveral crops comprising celery, potatoes, winter wheat andclover grass were successfully grown under the pilot system in
Heggelbach using a biodynamic approach. The results showedthat weather conditions are a significant factor in how theagrivoltaic system impacts the yield. For instance, differences inyields for potato crops growing under the facility compared toa reference plot varied from minus 20 percent in 2017 to plus
11 percent in 2018 when it was dry and hot.
Depending on the geographic location and local climate,growing crops under an agrivoltaic system can reduce
evaporation and protect against intense solar radiation.
This will become ever more important given the increasing
frequency of heat waves in Central Europe and Germany[20].
Research with potatoes has also shown that using agrivoltaics
can increase the proportion of sellable tubers.
Researchers at the University of Hohenheim collected data on
crop development, crop yield, harvest quality and microclimaticconditions, both under the agrivoltaic system and on
a reference plot without PV modules (see figure 27). This data
showed that photosynthetically active solar radiation under
the agrivoltaic system was 30 percent lower on average thanon the reference plot. Besides solar radiation, the agrivoltaic
system primarily affected the soil temperature and distributionof precipitation. The temperature of the soil under theagrivoltaic system was lower than that of the reference plotin spring and summer, although the air temperature remainedlargely the same. During the hot, dry summer of 2018, thewheat field had more soil moisture than the reference plot.
The initial yields from the test site in 2017 were promising:
The clover grass yield was only slightly below that on thereference plot, producing 5.3 percent less, but the reduced
yields of potatoes, wheat and celery caused by shading wereslightly more pronounced at 18 to 19 percent.
During 2018, which was a dry year, the winter wheat, potato
and celery crops produced higher yields than the referenceplot with no PV modules. Celery benefited most from these
conditions with 12 percent yield increase; potato and winterwheat crops increased their yield by 11 and 3 percent
respectively. The clover grass yield was 8 percent lower than
the yield on the reference plot. Calculations for the total yield
loss also need to account for the 8 percent loss as a result of
not being able to use the strips of land between the supporting
pillars for growing crops.
Results from 2019 showed reductions in yields for crops
growing under agrivoltaic systems amounting to 19 percent forclover grass, 28 percent for wheat and 33 percent for celeriac.
Wheat grown with agrivoltaics produced 2 percent more inyields in 2020.

Grass/clover mixture
Potatoes

Fig. 27: Field plan for the 2017 research site,
showing monitoring stations. Areas where
samples were taken are shown as boxes, and the

Celerypositions of the microclimate stations are shownas circles © BayWa r.e., modified by Axel Weselek/
University of Hohenheim.

Winter wheat31Agrivoltaics: Opportunities for Agriculture and the Energy Transition

3.2

20

Crop selection and cultivation

15

Cultivation under or between PV modules is not the same as
farming on “open fields.” There are differences in tilling (3.2.1),
crop management (3.2.2) and crop selection (3.2.3).

Yield difference (%)

10
5
0

3.2.1

5

Reconciling mounting systems and farming
machinery

-10
-15
-20
Winterwheat

Potatoes

CeleryGrass / clover
mixtureFig. 28: Crop yield differences under agrivoltaics compared
to reference plots, 2017 (blue) and 2018 (red) in Heggelbach(excluding land lost due to supports). Data: University of
Hohenheim, © Fraunhofer ISE

Fig. 29: Impact protection for the supports ofthe system in Heggelbach to protect against
possible damage from farming machinery© AGROSOLAR Europe GmbH

32

When planning a system, practical requirements need tobe taken into account before cultivation takes place. One
important requirement is that the system needs to be alignedwith the direction of tilling, and the distances between themounting system supports need to be suitable for the widths
and heights of the machines used. The machine operator needs
to get used to maneuvering between the pillars, especially atthe outset. In the APV-RESOLA project, the pillars are equippedwith impact protection to prevent damage to the system. The
actual land lost due to the pillars and impact protection in
Heggelbach was less than one percent of arable land. Because
it is often not practical to cultivate the strips between the
supports using machinery, around eight percent of the arable
land was not usable in the case of the research system in
Heggelbach. With manual cultivation or cultivation in rows,
the area lost is reduced to cover only the area that is actually
sealed. Innovative cabling techniques can also help to reduce
the number of supports to allow the largest possible area tobe cultivated (section 5.3). The use of precision farming andautomated track guidance systems makes cultivation easier.

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

3.2.2

Changes to the microclimate

Shading of the agricultural land changes the microclimate
below the PV modules. As well as the investigations in
Heggelbach described above, research has also been done
into possible effects on the microclimate at sites in the UnitedStates[21] and France[7]. Depending on the location and designof the system, the researchers were able to identify various
changes in the microclimate.

Partial covering of the agricultural land leads to an uneven
distribution of precipitation on the drip edges of the PV
modules. Measures should be taken in these areas tocounteract soil erosion due to run-off of nutrient-rich topsoil,
capping, washing out of seedlings or nutrient discharge andeutrophication of surface water. Some possible options can befound in the technology section (section 5).

In combination with the findings from APV-RESOLA, thefindings can essentially be summarized as follows:

These findings play an important role in agricultural practice.
For example, with systems that offer no protection or only
partial protection from rain, it is necessary to take into accountpossible changes in air circulation, humidity and risks of fungal
infections when choosing crop varieties. It is also important tokeep in mind that the decrease in solar radiation and canopy
temperature can prolong development time.

1.	 The solar radiation available to the crops can vary dependingon the technical design (e.g., the distance and orientationof the PV modules). As a guideline, a reduction in radiationof around a third can be considered acceptable for arable
farming in Germany.
2. The lower the height of the supports, the greater the
microclimatic changes.
3.	 On particularly hot days, the ground temperature decreases,
as does the air temperature to a lesser extent.
4. The wind speed can decrease or increase depending on theorientation and design of the system. Wind channel effects
and their impact on crop growth should therefore be taken
into account when planning the system.
5.	 Less groundwater is lost under an agrivoltaic system. The
hotter and drier the climate, the stronger the tendency
for soil moisture to increase compared to reference plots
without agrivoltaics.

Aside from practical considerations, knowledge of the
microclimatic effects of agrivoltaics also serves as a basis forselecting suitable crops. The partial shade underneath thesystem determines the suitability of individual crops.

Fig. 30: Illustration of an agrivoltaic apple orchard© Fraunhofer ISE

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

3.2.3

Suitable crops

Based on current knowledge, all types of crops are generally
suitable for cultivation under an agrivoltaic system, withdifferent effects on yields to be expected as a result of theshade provided. Highly shade-tolerant crops such as leafy
vegetable species (e.g., lettuce), field forage species (grass/clover mixture), various pomaceous and stone fruit and berry
species and other specialized crops (e.g., wild garlic, asparagus,hops) appear to be particularly suitable.

Fig. 31: Agrivoltaic system with solar tracking
PV modules in France © Sun’Agri

Permanent and specialized crops
Agrivoltaics is likely to offer the greatest potential for synergy
effects in the case of specialized crops from viticulture andfruit and vegetable growing. This is because the high added
value to area ratio and the often relatively sensitive crops
entail a greater need for protective measures. A sensibly
designed agrivoltaic structure can ensure direct protection
from environmental influences such as rain, hail and wind.
The supports can also be used to integrate additional protective
elements such as hail protection nets and polytunnels.
Agrivoltaics can help to reduce the amount of plastic used
so that less of it leaches into the soil. It also lowers the costsof conventional protective measures and the yield risk at thesame time.
Leafy vegetable cultivation with lettuce produced positive
results under an agrivoltaic system. The crops responded to the
reduction in light of approximately 30 percent with increased
leaf surface area growth[22], in a similar way to the celery in
Heggelbach.

Fig. 32: Weather protection for raspberries provided
by agrivoltaics. 300 kWp test system by BayWa r.e.
in the Netherlands © BayWa r.e.

34

In viticulture, on some types of vine the increased solar
radiation and temperature change caused by the climate crisis
have had a marked effect on yields, leading to sunburn as wellas water shortage. Greater solar radiation increases the sugar
content of the grapes, which in turn increases the alcohol
content of the wine and can impair its quality. A shifting ofcultivation regions and changes in harvest times can alreadybe clearly observed in many regions. In high temperatures, thepartial shade therefore has a positive effect on growth while
also preventing early ripening[23]. Compared to other types ofagriculture, in viticulture the agrivoltaic system only needs to
be two to three meters high, which significantly lowers thecosts of the mounting system. There are also potential cost
reductions to be achieved from integrating the agrivoltaic
system into existing protective structures. In France, agrivoltaic
systems are being increasingly promoted and implemented in
viticulture (section 2.7.2).

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Systems associated with pomaceous fruits such as apples arealso showing promise. Reducing the effects of the climate crisison the quality of the apples and harvest yields in Germany
often requires costly protective systems. Agrivoltaics can reducethese costs. For many types of apple, just 60 to 70 percent of
the available light is sufficient for optimum apple yields[24]. In
Rhineland-Palatinate, Fraunhofer ISE has set up a pilot system
on an organic orchard to investigate the effects of the PV
modules on pest infestations and yields compared to those of
conventional protective measures. Synergy effects are expectedin hop production as well: The mounting system can be usedboth as a climbing aid for the hops and as a fitting for the PV
modules. This can substantially lower the costs of a hop yard.
On the other hand, crops and cultivation systems that aresusceptible to moisture-related fungal infestations that cannot
be reduced with accompanying cultivation techniques appear
to be less suitable.
Another area of application among specialized crops is theprotected cultivation of berry bushes. Here, PV modules
could take on part of the function performed by polytunnels,
providing protection against rain and hail. Other advantages ofsystems installed above permanent and specialized crops relate
to cost-effectiveness (section 4), societal acceptance (section 6)
and regulatory feasibility (section 7).

Arable farming
The results from Heggelbach with various agriculturally relevant
crops show that, especially in dry areas, these crops can clearly
benefit from the shade of stilted, overhead agrivoltaic systems.
The positive effect on yields in hot and dry years is particularly
worth emphasizing. In years of high precipitation, on theother hand, crops such as potatoes, wheat and other grains(barley, rye or triticale) under fixed mounting systems should be
expected, as in the case of Heggelbach, to suffer yield losses of
up to 20 percent. In temperate latitudes, corn is not well suited
to cultivation in partial shade because of its characteristics
as a C4 crop (higher heat and light demand). There is little
experience so far with other popular crops such as canola,
turnips and legumes. It is recommended — including in viewof achieving broad acceptance among the population and in
farming — that total yield losses should not exceed 20 percent.
The findings from Heggelbach show that this is achievablefor some relevant arable crops in Germany through suitable
light management, which involves having a lower density of
PV modules and adjusting the orientation of the PV modules.
Movable, stilted, overhead agrivoltaic systems can reduce losses
in crop yields because the available light can be increased in
critical growth phases.

Fig. 33: Demo project in berry cultivation shows high value

Fig. 34: Harvesting wheat with a combine harvester

creation in agriculture © BayWa r.e.

© Fraunhofer ISE

35

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Light saturation point
Crops need light for photosynthesis. The ability tomake use of incident light differs from crop to crop.
The rate of photosynthesis stagnates after a certain
level of light intensity depending on the species ofcrop (see figure 35). An important criterion in deter‑mining the suitability of crops for agrivoltaics is thelight saturation point. After this point, crops cannot
convert any more light into photosynthesis output,
and can even become damaged. The lower the point
at which a crop reaches light saturation, the better
suited that crop is for cultivation under an agrivoltaic
system.[21]Grassland
Dual agricultural use for ground-mounted PV systems andsheep farming is common practice in Germany. These systems
are typically optimized purely on the PV side. The expectedsynergy effects and the agricultural added value to area ratio
are relatively low compared to other agrivoltaic applications.
However, concrete research findings are still needed in this area.
A new approach, which allows the land to still be farmed
over at least 90 percent of the area even when the stilts areclose to the ground, is the installation of vertical agrivoltaic
systems (see figure 36). In Germany, there are already several
reference systems, such as those in Donaueschingen (BadenWürttemberg) and Eppelborn-Dirmingen (Saarland). The main
advantages for crop growth are expected to be in windy areas
such as those close to coastlines, where the PV modules canact as wind barriers to prevent wind erosion.

Photosynthesis rate

Sun Loving Crops

Light saturation point

Shade Tolerant Crops

Intensity of sunlight
Fig. 35: Graph of the rate of photosynthesis against intensity ofFig. 36: Vertically deployed, bifacial PV modules used within

sunlight for sun loving and shade tolerant crops[24]the agrivoltaic system in Eppelborn-Dirmingen, Saarland, with

© ASPS, modified by Fraunhofer ISE

2 MWp of capacity, built by Next2Sun © Next2Sun GmbH

36

3.3

Reports from farmers

The farmers in Heggelbach report chiefly positive effects,
but also clearly note the limitations due to the existing
regulatory framework in Germany. In an interview, Thomas
Schmid and Florian Reyer explain why they have chosenan agrivoltaic system, how practically feasible it is and how
they think the legal regulations should be changed. Thomas
Schmid is a co-founder of the farming community DemeterHofgemeinschaft Heggelbach, founded in 1986. Since then,he has withdrawn from active farming and now works on
the supervisory board of the Demeter association and asa consultant in Baden-Württemberg. Florian Reyer has beena partner in Hofgemeinschaft Heggelbach since 2008 withresponsibility for the areas of renewable energy, technology,
agriculture and vegetable farming.

Interview with Thomas
Schmid and Florian Reyer
What drove you as an agricultural practice partner
to take part in the pilot project and make your landavailable for a pilot system?
Schmid: “For 15 years, we have had the ideal of achieving notjust a closed operational cycle but also a closed energy cycle on
the farm. Because of that, we have invested in various sourcesof energy in the past (note: wood gas power, roof PV systems).
When Fraunhofer ISE approached us in 2011, the energy
transition was already a major topic. Agrivoltaics seemed to be
an opportunity for us to play our part in a successful energy
transition and also, through dual land use, to showcase analternative to biogas production on agricultural land.”Reyer: “We’re also interested in innovative developments inrenewable energies in general.”How did the planning and construction go? Were all yourrequirements taken into account, like maintenance of soil
functions for example?
Schmid and Reyer: “As a full practice partner, we wereinvolved in the entire planning process and we had a say inthe decisions made in every area, so our agricultural needs andour high demands for maintaining soil fertility were consideredfrom the start. For example, a temporary construction road waslaid to build the system, and a special anchoring system wasused to eliminate the need for concrete foundations.”

Fig. 37: Thomas Schmid and Florian Reyer from
Hofgemeinschaft Heggelbach © AMA Film GmbH

How practical is it for you to farm under the system?
Reyer: “In terms of the benefits of dual use, it’s totally practical.
That also means that some of the constraints on cultivation
aren’t relevant. If you want to do it, you can.”What benefits do you get from generating power using
the system?
Schmid: “Our aim is to use as much of the energy produced
ourselves as possible so we can reduce energy costs. That’s
why we’re trying to further increase consumption of ourown energy and, with the help of our practice partner,
Schönau power station, to adapt storage, management andconsumption to the power that is generated.”
Given what you know now, would you choose to build
this system again?
Reyer: “As a research system, yes, but not under the current
regulations.”
Why? What do you think needs to change for agrivoltaics
to be used successfully in the future?
Reyer: “It’s all about the regulations. Everything needs tochange!”Schmid: “The regulations in Germany* are not right at
the moment. Building the system means we don’t get an
agricultural subsidy for the land any more. At the same time,
we don’t get compensation under the Renewable Energy
Sources Act for feeding the power that’s generated into
the grid.”
Reyer: “New technology needs funding to incentivize people
to use it in practice. It also requires political will to adapt theunderlying regulations accordingly.”
Schmid: “More research is also needed to test the technology
in other areas of use, such as hop production, fruit growing
and even conventional agriculture.”*

The statements refer to the regulatory conditions in 2019.
Some conditions have since been adapted, see also section 6.

37

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

4

Profitability andbusiness models

Note: The assumptions and calculations relating tocost‑effectiveness provided in section 4 are from 2020and do not reflect the current development in prices.

unwanted weeds from spreading. Dual use can also be
expected to enable cost reallocations or savings on leased land.
This is addressed in section 4.1.2.

The costs of agrivoltaics are highly individually variable anddepend on factors such as installed capacity, agriculturalactivity, system location and the PV module technology
used. The acquisition cost is generally higher than that ofa conventional ground-mounted PV system; in the case of
stilted, overhead systems, this is mainly due to the higher,
more elaborate mounting system and the need to produce thePV modules specially. The clearance height and the spacing
between the posts have a significant effect on the cost of
the mounting system. Using smaller farming machinery or
performing as many operations as possible manually can havea positive effect on cost-effectiveness. Perennial row crops
also provide cost advantages, because the mounting system
posts can be integrated into the rows with no appreciable
loss of acreage. Especially when the crops on the agriculturalland need to be protected in any case, investing in an
agrivoltaic system can be lucrative from the point of view ofan agricultural business, as there are potential savings to bemade here. Unlike conventional ground-mounted PV systems,
overhead agrivoltaic systems do not usually need to be fenced
in, which eliminates this as a cost factor.

A distinction is made between interspace and stilted, overhead
agrivoltaic systems below for the purposes of cost estimates.
Stilted, overhead systems are further divided into systems over
2.5 meters and those with a height of 4 meters and above.
Ground-mounted PV systems and small rooftop PV systems areused as references. Because of the high economic complexityof the overall system, the following considerations are limited
to the PV level. Income and expenditure from farming activities
have not been taken into account in this estimate.

When in operation, slight cost savings are expected withagrivoltaic systems compared to ground-mounted PV systems,
as steps such as pruning the vegetation under the PV modules
are already carried out as part of agricultural operations.
Only the non-tillable rows should be maintained to prevent

38

A trend can be observed in arable farming whereby systems
with a higher installed capacity are needed in order toimplement agrivoltaics in an economical way. In horticulture,smaller systems can also be economical if conditions arefavorable. Crop rotations in arable farming mean that thedesign of the agrivoltaic system needs to be adapted to
the needs or tilling methods used for all of the crops in therotation. For permanent crops, on the other hand, the designof the system can technically be adapted entirely to the needs
and cultivation of the single crop.
The underlying figures used here represent estimatedmedium-term costs and income. Cost fluctuations and supply
bottlenecks, such as those due to the coronavirus crisis or the
war in Ukraine in the case of steel and module prices, have notbeen taken into account in the calculations.

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

4.1

Capital expenditure

The capital expenditure estimates are based on an area of
two hectares and, for the roof system, an installed capacityof 10 kWp. Because arable crops that are typical in Germany,such as wheat, barley or canola, tend to need more light thanhorticultural crops, larger spaces between the PV modules havebeen assumed for stilted, overhead agrivoltaic systems of four
meters and above, and therefore a lower capacity to area ratioof 600 kWp per hectare. The mounting system clearance heightand spacing between posts correspond to the dimensions of
the system in Heggelbach. For low permanent crops such as
berries, a capacity of 700 kWp per hectare and a clearance
height of three meters have been assumed. In permanent
grassland, a capacity of 300 kWp per hectare is used for the
calculations, as in this case the distance between rows ofmodules increases accordingly to enable cultivation to takeplace.

1.	 The module price may increase, as the size or lighttransmission of the modules can be adjusted to the crop’s
growth needs (section 5.2). When using bifacial doubleglass PV modules, an average increase of 326 euros per kWp
has therefore been assumed in the example calculation.

Aside from the aspects mentioned, the costs of power
inverters, electrical components, grid connection and projectplanning are, according to current information, comparable
to those of ground-mounted PV systems in most cases. Some
small savings can be made by not fencing off the system.

CAPEX (€/kWp)

For ground-mounted PV systems, a capacity of 1 MWp per
hectare has been used. An optimistic and a conservative
scenario reflect the expected range of costs. For the agrivoltaic
scenarios, any possible risk premiums or additional costs tocomply with legal conditions have not been taken into account.
The values therefore correspond to the estimated mediumterm costs in the event of an agrivoltaic market launch. The
differences between the capital expenditure expected forground-mounted PV and that for agrivoltaic systems are shownin figure 38. The differences in capital expenditure are largely
attributable to three cost points:

In the case of special modules, such as semi-transparent PV
modules, the assumed price is between 240 and 440 euros
per kWp. These additional expenses associated with bifacial
PV modules can be offset in part by the increased power
generation to installed capacity ratio.
2. For the mounting system, average costs of 372 euros per
kWp are expected in the case of stilted, overhead agrivoltaic
systems (> four meters), compared to 76 euros per kWp forground-mounted PV systems. However, this estimate (still)contains many uncertain elements, and fluctuates between
243 and 500 euros per kWp depending on the design aswell as on possible learning effects and economies of scale.
For interspace systems, the cost of the mounting system issignificantly lower, at 97 to 167 euros per kWp. For stilted,
overhead systems under four meters, this is between
243 and 306 euros per kWp.
3.	 The site preparation and installation costs are alsosignificantly higher, and in the case of stilted, overheadsystems (> four meters) are estimated to be 190 to
266 euros per kWp (ground-mounted PV systems:
67 to 100 euros per kWp). Cost-driving factors include
soil protection measures such as the use of construction
roads and less flexibility with regard to installation, because
cultivation times for agriculture and the trafficability ofthe soil need to be taken into account. In the case ofinterspace systems or stilted, overhead systems under four
meters, lower average costs of 93 and 137 euros per kWp
respectively may be expected.

400

Ground-mounted PV

350

Agrivoltaics, interspace

300

Agrivoltaics, overhead, > 4 m

250

Agrivoltaics, overhead, > 2.1 m

200
150
100

Fig. 38: Estimated capital

50

mounted PV and agrivoltaic

0systems © Fraunhofer ISE

expenditure (CAPEX) for ground-

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39

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

4.2

Operating costs

2. The agricultural use eliminates the costs of maintaining theareas under the PV modules on the PV side.
3.	 However, the costs of cleaning the PV modules or repairing
the system are likely to be higher if this work needs to bedone at a greater height, for example using lifting platforms.
Because the regular rainfall in Germany means that thecosts of cleaning PV modules are only minor, this additional
cost is likely to be manageable. In regions with a higher
probability of soiling, the additional costs of cleaning
may be far more significant depending on the cleaning
technique used. Experience regarding the long-term effects
of fertilizers and crop protection products on the mounting
system and PV modules is currently limited.

The costs of agrivoltaic systems are individually variable,
and there is a tendency for there to be potential savings on
operating expenses, unlike on capital expenditure, compared to
ground-mounted PV systems. For the most part, the savings areaccounted for by the following:
1.	 The costs for providing the land are reduced from around2 euros to 1.3 to 1.6 euros per kWp. For this estimate, it
was assumed that the area costs for agrivoltaic systems are
based on agricultural lease rates and are divided equally
between the farm and the operator of the agrivoltaic
system. This figure may vary depending on the ownership
structure and business model. The potential savings may behigher in arable farming and on grassland because lower
lease rates are more common than in horticulture.

10
Dark: OPEX

9Light: CAPEX

∑ 8.1

8

6

∑ 5.4

5

1.26

1.38

4
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(CAPEX) and operating expenses (OPEX) of

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Fig. 39: A comparison of estimated levelized

∑ 7.5

1.26

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

4.3

Levelized cost of electricity

4.4

Self-consumption and revenue frompower generation

It can be concluded that the costs for the production ofelectricity in the case of stilted, overhead agrivoltaic systems(> four meters) over a period of 20 years with average electricity
generation costs of 8.15 euro cents per kWh are around50 percent higher than those for the average ground-mounted
PV system, and more cost-effective on average than small roof
systems. For interspace agrivoltaic systems, on the other hand,electricity generation costs amount to 6.03 euro cents on
average, only slightly higher than those of a ground-mounted
PV system. The range of electricity generation costs of agrivoltaic
systems compared to ground-mounted PV systems and small
roof systems is shown in figure 40.

Power from an agrivoltaic system is usually most lucrative
when it is used for the producer’s own consumption, thereby
reducing the need to purchase electricity externally. For
example, if the cost of purchasing electricity commerciallyis 14 to 16 euro cents per kilowatt-hour[25] (and the cost ofgenerating electricity is 7 euro cents per kilowatt-hour), thepotential savings are 7 to 9 euro cents per kilowatt-hour.
To achieve high direct consumption, it is beneficial to havea consumption profile that is similar to the generation profile,with peaks in the middle of the day and in the summer. These
generation peaks can be shifted depending on the orientationof the agrivoltaic system.

The cost estimate does not take into account the fact that
economies of scale in arable farming and on grassland could
lead to a cost advantage because of a tendency towards larger
field sizes and therefore larger agrivoltaic systems. The sameadvantage is also likely to apply in arable farming and on
grassland with regard to fixed costs (such as project planningand grid connection) because a larger system means that thesecosts are lower relative to the system’s size, thereby potentially
improving overall cost-effectiveness. On the other hand, small
systems, which will increasingly be found in horticulture due tothe small field sizes, may also offer advantages in terms of costeffectiveness, e.g., if the farms use the generated electricity for
their own purposes. With an appropriately designed regulatory
framework, decentralized locations close to the consumer
could lead to additional incentives to build agrivoltaic systems.

For applications such as cooling, where energy can be stored,
thermal storage allows the consumption profile to be adapted
to the generation of electricity. Charging vehicle batteries isanother way in which the generation profile can be taken into
account and producer consumption can be increased.
Given the falling costs of stationary energy storage, this could
also be a cost-effective way to ensure a favorable consumption
profile, and should be considered on a case-by-case basis. For
PV energy that cannot be consumed immediately or stored,a buyer needs to be found. This usually relies on models basedon the German Renewable Energy Sources Act or electricity
supply contracts. Section 7.4 describes the circumstances underwhich compensation is available under the Renewable Energy
Sources Act.
Some energy suppliers will buy energy from operatorsof PV systems through electricity supply contracts. The
Umweltbank AG, for example, has drawn up an electricity
supply contract template for ground-mounted PV projects.

18
16
14
(€ cent/kWh)

12
10
8
6
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Fig. 40: Estimated levelized cost of electricity (LCOE) for groundmounted PV and agrivoltaic systems © Fraunhofer ISE

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41

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

4.5

Business models

Because agrivoltaic systems incorporate agricultural land, thebusiness models are often more complex than for groundmounted PV. Depending on the parties involved in the project,
its implementation can often involve different players or areasof responsibility with different functions.
There are at least four different areas:
1.	 Provision of land (ownership)
2. Agricultural use of the land
3.	 Supply of the PV system (ownership/investment)
4. Operation of the PV system
Basic case: “Single-entity model”
In the simplest business model, all four areas may be dealt
with by a single party — typically a farming business. Thismodel is mainly used for smaller agrivoltaic systems close tofarms in western Germany. This is because those who farm
the land on these farms are often also the owners, and thecapital expenditure could be manageable. This business model
has a number of advantages: Firstly, the costs of projectplanning and the complexity of contract negotiations arelower. Secondly, the advantages and disadvantages of anagrivoltaic system are easier to estimate if the income fromthe agricultural and the photovoltaic activity goes to theWhat should a farm ideally bring to thetable?
Beneficial factors for the economical implementationof agrivoltaics:
A good connection to the grid in terms ofproximity and capacity
Row cultivation
Permanent crops
Protected cultivation
Low employment of machines/low clearance
heightA large, contiguous area (> 1 hectare)
A low slope
High and flexible energy consumption(e.g., cooling, drying, processing)
A willingness to invest

42

same economic entity. This is particularly relevant in the caseof agrivoltaic systems because of possible interactions between
the two areas of activity. For example, bifacial PV modules
can increase albedo values, and therefore electricity yields,
depending on the choice of crop and the agricultural operations.
The producer’s ability to use the energy generated and thefact that many farms have already installed roof systems, andtherefore have experience operating PV systems, are also points
in favor of this business model.
External land ownership
In many cases, however, the land is not owned by the farming
business itself. This can be seen from the high proportion ofleases in Germany, particularly eastern Germany[26]. If the otherthree responsibilities at least are all in the hands of the farming
business, it can still benefit from the synergy effects describedabove. As in the case of ground-mounted PV projects, thisrequires long-term land lease and use contracts, usually witha term of more than 20 years.
External PV investment
For large agrivoltaic systems, it is also likely to be moreunusual for the farming business to own the PV system, andthe likelihood of external investment is likely to increase.
Part‑ownership could help to create an incentive structure forsynergetic dual land use. The larger the proportion of borrowed
capital, however, the more difficult it will be to maintain an
overview of the use of both production levels during ongoing
operations. This business model nonetheless has the potential
for economies of scale and optimization thanks to greater
division of labor.
Shared responsibilities
In the example of the pilot system in Heggelbach, the mix ofplayers involved is relatively complex. The ownership of theland, the ownership of the PV system and the operation of
the farm and PV system are all in the hands of other parties.
Figure 41 shows the basic structure of the required network ofcontracts. It remains to be seen what configurations will become
established in Germany; this will depend significantly on the
future regulatory framework. Cooperative models, with multiple
farmers working together, are also a possibility.

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

SpatialLicenseplanning
Municipality

agreement

agreement

Community

Agrivoltaic systemownersAgrivoltaic

Land usesystem lease

contract

agreement

Land owners
Agrivoltaic system

Land lease

operators/land tenants

contract

Construction
company,
maintenanceElectricity
Maintenancesupplycontracts

work

Electricity
distributors

Fig. 41: Stakeholder groups and contractual model © Fraunhofer ISE

Table 06: Configurations of different agrivoltaic business models (based on Schindele et al. 2019[5])Business model

Function
Providing land

Agricultural
management

1. Base case
2. External land ownership

Providingthe PV system

Operatingthe PV system

FarmLand owners

3. External PV investment

Farm
Farm

PV investors

Farm

4. Cultivation and operation only

Land owners

Farm

PV investors

Farm

5. Cultivation only

Land owners

Farm

PV investors

PV operators

43

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

5

Technology

The way that power generation works is the same for agrivoltaic
systems as for ground-mounted PV systems. However, therequirements of agrivoltaic systems in terms of technicalcomponents and supports for the system are different because
the land used is also being cultivated at the same time: The
module technology, the height and alignment of the system,
the mounting system and the foundation all need to beadapted to farming using agricultural machines and the needsof the crops. Sophisticated light and water management is also
important in order to ensure that yields are sufficiently high andconsistent.
To enable dual use of the land for agricultural production andpower generation, the PV modules are installed with elevatedsupports three to five (or, in the case of hop growing, morethan seven) meters above the field, depending on the use case.
This allows even large agricultural machines, such as combine
harvesters, to work the land underneath the agrivoltaic system.
To ensure that the crops get enough light and precipitation,

the spacing between the PV module rows is often wider thanin conventional ground-mounted PV systems. This typicallyreduces the degree of surface coverage to around one third. In
combination with the high supports, this process ensures that
there is enough available light. When using solar tracking PV
modules, the light management can be adapted specifically tothe development stage and the needs of the individual crops[27].
However, at the same time there is an increase in technicalexpenditure as well as in the work involved in control andinstrumentation.
The mounting system, and in some cases also the PV modules,
are often different from those used in ground-mounted
PV systems. There are different technologies and designs tochoose from, adapted to site-specific requirements and farming
conditions. In general, agrivoltaic systems should be state-ofthe-art and comply with commonly accepted regulations andstandards (see section 2.3 on DIN SPEC).

Fig. 42: Stilted, overhead system enabling cultivation with

Fig. 43: PV modules with spatially segmented solar cells

a potato harvester © Hofgemeinschaft Heggelbach

and protective function in the Netherlands © BayWa r.e.

44

Fig. 44: Bifacial, verticallyinstalled PV modules by
Next2Sun, Eppelborn-Dirmingen© Next2Sun GmbH

5.1

Approaches to agrivoltaic
system construction

Agrivoltaic systems, as already in use in countries such as
France and Japan, are often mounted on elevated supports.
The clearance height describes the unobstructed vertical space
between the ground and the lowest structural element. Various
possible system structures are described below.

Fig. 45: PV modules abovea polytunnel © BayWa r.e.

Stilted systems offer significant potential for synergy effects(see section 3). Ensuring that cultivation under the PV modules
remains possible poses particular structural and economic
challenges, particularly for stilted, overhead systems in arable
farming.
If, as well as generating power, PV modules also perform thefunction of protecting against hail, rain, night frost and otherextreme weather events, the use of special PV modules isa natural choice. Figure 43 shows a research system by BayWar.e. above a fruit orchard. This system in the Netherlands wasbuilt using PV modules with wider cell spacing, which increases
the sunlight available to crops and can also enhance the roofingand protective function by means of transparent module parts.

Fig. 46: Special thin-film
tubular modules fromTubeSolar © TubeSolar AG

There may also be synergy effects with PV modules installed
close to ground level. Next2Sun accomplishes this by using
bifacial PV modules that are installed vertically. While this typeof system is more cost-effective due to the lower mounting
system, it also offers fewer light management options. One
advantage of interspace systems could be a reduction in windspeed, which in turn has a positive effect on evaporation andreduces the risk of wind erosion.
Fig. 47: Semi-shade from

Another possible design is provided by TubeSolar AG in theform of tubular PV modules installed horizontally on supports.
This innovative approach promises spatially uniform lightand water permeability, which is particularly important inagricultural production with no artificial irrigation. Agratio
GmbH combines these novel PV modules with a low-cost
cable structure used as a support.
In Japan, narrow PVmodules are installed above agriculturalland in a concept called “solar sharing” to adjust theavailability and distribution of light. There are many otherpossible technical solutions, each with its own advantages
and disadvantages.

tubular PV modules installed
between tension cables by
TubeSolar © sbp sonne GmbH

Fig. 48: Stilted, overheadsystems with narrow PV
modules in Italy © REM Tec

45

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

5.2

PV module technologies

All types of PV modules can in principle be used for agrivoltaics.
PV modules using wafer-based silicon solar cells account foraround 95 percent of the global PV market. The usual design
calls for a glass pane on the front and a white covering filmon the back. Opaque solar cells are connected and laminatedbetween these in series at a distance of 2–3 mm. A metalframe is used for mounting and stabilization.
Where there is a transparent back covering (glass, film), thespaces between the cells allow most of the light to passthrough and, in the case of agrivoltaic systems, to reach thecrops below. With the PV modules that are currently mostcommon, the spaces between the cells make up four to five
percent of the surface area. To increase light transmission,
however, the spaces can be widened and the PV module
frames replaced by clamp mountings. PV modules witha larger ratio of transparent to total area protect crops against
environmental influences without limiting the available light tothe same extent.
Bifacial PV modules can also use the light that hits the reverse
side to generate electricity. Depending on the level of radiationon the reverse side, this can increase electricity yields by up to
25 percent. Because agrivoltaic systems tend to have a larger
distance between rows and taller supports, the reverse sides of
the PV modules tend to receive more light than conventional
ground-mounted PV systems. Bifacial PV modules are therefore
often well suited to agrivoltaics. Another advantage of PV
modules with a double glass structure is the increased residualload-bearing capacity if the glass shatters, which benefits roadsafety as well as occupational health and safety.

Thin-film PV modules (CIS, CdTe, a-Si/µ-Si) can be installedon flexible structures, making cylindrical bending possible.
While their structure is otherwise identical, their weight isapproximately 500 grams per square meter of surface arealess than that of PV modules with wafer-based silicon solar
cells. Their efficiency is somewhat lower, however. The cost to
surface area ratio of thin-film PV modules is somewhat lower
than that of silicon solar cells.
The same applies to organic photovoltaics (OPV). In contrast
to silicone-based crystalline PV modules, they are composedof organic carbon compounds. Selective spectral adjustmentof the active layers of OPV systems is in principle also possible,
which means that those layers can be incorporated into flexible
base films. For example, part of the solar spectrum can betransmitted into PV polytunnels and used by the crops growing
below. The current challenges of OPV films include low
efficiency and durability.
In concentrator photovoltaics (CPV), lenses or mirrors focus
the light onto small photoactive surfaces. CPV modules needto have solar tracking, with the exception of systems with low
concentration. Diffuse light is largely transmitted. Spectrally
selective approaches can also be carried out using CPV if thereflective layers reflect only part of the solar spectrum. Thereare currently only few commercial suppliers of CPV modules foruse in agrivoltaics. One example is the Swiss company Insolight.

Fig. 49: Stilted, overheadsystem with continuous rowsof modules © Sun’Agri

46

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

5.3

Mounting system and foundation

5.3.1

Mounting system construction

As well as the clearance height and working width, the headland
for the agricultural machines to be used also needs to be taken
into account with agrivoltaic systems. The distance between
the ground and the bottom of the structure (clearance height)
is typically at least five meters for stilted, overhead systems
in arable farming. The advantages of such clearance heights
include not only making the land more easily trafficable, butalso producing a more even distribution of light underneaththe PV modules. On the other hand, the capital expenditure forthe mounting system is lower for interspace agrivoltaic systems
because they use less steel and have lower structural demands.
As row spacing becomes significantly larger, the area of land
required by an agrivoltaic system increases, as does its cost,
relative to the electricity yield.

5.3.2

Single and dual-axis solar tracking

There are systems, for instance in France, that work withsingle- or dual-axis tracking. This means that the direction inwhich the PV modules are facing is adjusted by a mechanism totrack the position of the sun. With single-axis tracking, the PV
module field either follows the sun horizontally according to its
angle of incidence (elevation) or vertically according to its orbit(azimuth). Dual-axis trackers do both, and therefore produce
the highest solar power yield. However, dual-axis systems
with large PV module tables can create an umbra under the
PV modules, while other parts of the land receive no shade atall. Notwithstanding the higher acquisition and maintenancecosts, however, tracking can optimize energy yields and light
management for crop farming[27] (section 5.4). The flexible
angle of inclination allows tracking systems to optimize theirconstructive protection against hail or extreme sun by adjusting
their orientation as appropriate.

Fig. 50: Single-axis tracker
system on a demonstration
system in France © Sun’Agri

47

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

5.3.3

Anchoring and foundation

The anchoring or foundation needs to ensure the statics andstability of the agrivoltaic system. Proof of fulfillment of thesesafety requirements must be provided when building a system(see section 5.7.2). Concrete foundations are not recommended
in view of protecting valuable farmland. Alternative options
include piled or screw foundations, which allow the system tobe removed without leaving any traces.
Mobile agrivoltaic concepts make it possible to assemble thesystem, disassemble it again and install it in another location
without using large machinery. One possible benefit is that,
because this is not a structural alteration, a building permit may
not be necessary. This means that mobile agrivoltaics can be
flexibly adapted to farming, and even deployed spontaneously
in crisis regions.

Fig. 51: Spinnanker anchor with anchor plate and threaded

Fig. 52: Illustration of different system types oriented east-west,

rods provides the foundation for the installation system

south and south-east © Fraunhofer ISE© Spinnanker GmbH48

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

5.4

Light management

The sun’s path over the course of the day and its changing
position over the year mean that the shadow cast over the
farmland changes constantly. In most cases, light should ideallybe as homogeneous as possible for healthy crop growth,
uniform ripening and maximizing potential synergy effects.
This can be achieved in various ways:
1.	 Simulations and measurements show that a south-easterly
or south-west orientation at an angle of 30 to 50 degrees todue south results in even shading. For the Heggelbach site,an angle of 45 degrees to due south was used. A power
generation loss of around five percent was built into thecalculation. The actual alignment may differ depending on
local conditions.
2. Another option is to maintain the southerly orientation anduse narrower PV modules. This approach is frequently usedin Japan, where it is referred to as “solar sharing.”
3.	 Uniform light conditions can also be achieved by aligning
the PV modules east-west. This alignment maximizes the
movement of shadow over the course of the day. To avoid
the creation of an umbra under the fixed and completely
opaque PV modules, the width of the PV module rows
should be considerably less than the height of the system.
As a rule of thumb, the clearance height should be at least
1.5 times as great as the width of the PV module rows, or atleast twice as great for tracking PV modules. For transparent
PV modules, on the other hand, this factor is reduced inboth cases depending on the degree of transparency.
4. Another option for achieving targeted light management
and higher electricity yields is the use of single- or dualaxis tracking PV modules. As described in section 5.3.2,
however, this type of PV modules entails higher capital
expenditure and maintenance costs. Dual-axis tracking
systems that use large PV module tables tend to be lesssuitable for the cultivation of crops because an umbra
usually forms underneath the PV modules, while other partsof the land are permanently exposed to full sunlight.

Fig. 53: The shaded strips underneath the PV modules movewith the sun’s position © University of Hohenheim

Fig. 54: Transparent PV modules casting a shadow over vines© Hochschule Geisenheim University

49

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

5.5

Fig. 55: Concept for a rain collection facility
with storage tank © Fraunhofer ISE

When it rains, rainwater running off the edges of the
PV modules can cause soil erosion and wash away the soil.
There are various approaches that can be taken to avoid
negative consequences for crop growth and soil quality: For
example, as with light management, narrow PV modules or
PV tubes can prevent large quantities of water from collecting
on the edges of the PV modules. However, if the PV modules
are intended to provide constructive protection for the crops, it
is preferable to prevent run-off by using tracking PV modules[28]or by channeling away the rainwater. If using the latter option,
it is important in most cases to ensure that sufficient water isprovided through irrigation. Collecting and storing rainwater
can help to conserve groundwater resources, or even make itpossible to farm in the first place, especially in arid regions.

5.6

Fig. 56: Agrivoltaic system in Heggelbach with a capacityof 194 kWp covering approximately a third of a hectare© Fraunhofer ISE

Fig. 57: Eppelborn-Dirmingen solar farm with 2 MWp withvertical solar fences by Next2Sun © Next2Sun GmbH

50

Water management

Size of the PV system

The size of agrivoltaic systems can vary considerably fromcountry to country. While Japan has an increasing numberof smaller systems ranging from 30 to 120 kWp, in China
there are already agrivoltaic systems with capacities ofseveral hundred MWp. The key criteria include not only costeffectiveness, decentralization of energy generation and social
aspects, but also the impact on the farming landscape, which
in turn affects social acceptance. The path that Germany willtake remains to be seen and may also differ from region toregion. The regions of southern Germany, which mostly havesmaller land parcels and sensitive landscapes, are better suited
to smaller systems, typically installed above specialized crops.
In northern and eastern German regions, on the other hand,larger systems may be more practical given the larger landparcels there, not least because the economies of scale could
compensate financially for the lower annual solar radiation.
The amount of land required by stilted agrivoltaic systems istypically 20 to 40 percent more than that of ground-mounted
PV systems. This means that stilted, overhead agrivoltaic
systems have a capacity of 500 to 800 kWp per hectare,
while a conventional ground-mounted PV system can achieve
700 to 1100 kWp per hectare, depending on the type ofsystem. Interspace agrivoltaic systems, on the other hand,manage just 250 to 430 kWp per hectare, meaning that theyrequire around three times as much land as ground-mounted
PV systems.

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

5.7

Approval, installation and operation

Stilted agrivoltaic systems, which are classified as structural
facilities by definition, generally use glass/glass PV modules. In
Europe, the PV modules are subject to electrical requirements
through their certification under the “Low Voltage Directive
2014/35/EU” (IEC certification for approval as an electricalcomponent), as well as requirements for construction products
regarding the use of glass in the construction industry underthe “Construction Products Regulation (EU) 305/2011.”
Unlike conventional ground-mounted PV systems, agrivoltaic
systems are expected to be navigated by machinery. To ensurethat it is safe to work under the glass/glass PV modules, theplanning, measurement and design of the PV modules issubject to particular requirements. These are set out in the
Administrative Provisions of the Technical Building Regulations(Verwaltungsvorschriften der Technischen Baubestimmungen,
VwV TB) of each of the federal states. In addition, therequirements regarding the usability of construction products
set out in the building code of each state (Landesbauordnung,LBO) must be observed.
Glass used in the construction industry is subject to certain
design and construction rules to ensure the necessary level ofsafety and protection. These rules make it mandatory to use
glass with safe shattering behavior (see “DIN 18008 Glass inbuilding — design and construction rules” series of standards).
Stilted agrivoltaic systems use a structure that can be classified
as overhead glazing, because it is normally necessary to carryout work underneath the PV modules. If so, the residual loadbearing capacity of the structure if the glass shatters must be
ensured without any appreciable consequences in terms ofdamage or injury. This can be achieved by selecting appropriate
products, such as laminated glass and suitable modular frame
structures. Some manufacturers sell glass/glass PV modules thatare IEC certified under the Low Voltage Directive for use within
the regulatory scope of DIN 18008 through a general building
approval (Allgemeine bauaufsichtliche Zulassung, AbZ) andgeneral type approval (allgemeine Bauartgenehmigung, aBG).

If an agrivoltaic system deviates from European and German
electrical regulations or building regulation law, a separate
permit from the building authorities is required to build the
PV module, or appropriate proof of usability is required touse it in this special construction context. Aside from this,proof of load-bearing capacity and serviceability is required foreach agrivoltaic system, including PV module coverage. Thisis dependent on geometry, location, net weight and possible
meteorological effects such as wind, snow or thermal loads. It
is also necessary to ensure that the potentially extreme stressfrom external influences is always less than or equal to thestress resistance of the components. Furthermore, a guarantee
is required that the loads from the agrivoltaic system, made up
of its net weight and external influences, can be transferredsafely by the mounting system into the subsoil.
Additional information can be found in the brochure: “AllianzBIPV_Techn-Baubestimmungen.pdf” available for download
free of charge from https://allianz-bipv.org/.
It should be noted that the descriptions given here are
generally applicable throughout Germany. Consultation withthe competent legal board of construction for the federal stateof the construction project is recommended for each agrivoltaic
system. The requirements and regulations applicable to thespecific project (project-specific type approval) must be checkedor evaluated. Specific cases may be resolved on a case-by-casebasis taking into account the local conditions and construction
framework, even within the regulatory area or with a special
verification concept and special measures, possibly with anapplication to deviate from regulations.
In the future, some exceptions may even be introduced for
agrivoltaic systems at the state or federal level as part of
the government’s energy transition policy, which could thenin turn be implemented in state law (construction law) by
the individual federal states. It is worth keeping an eye on
developments in this area.

51

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Fig. 58: Working in an agrivoltaic system under the PV modules© Fabian Karthaus

5.7.1

Approvals process for agrivoltaic systems

Some specifics must be considered in the approval process
for the construction of an agrivoltaic system. The required
documentation should be prepared in close coordination
with the technical side. Table 7 provides an overview of thenecessary approvals, expert opinions and documents.
In the case of the research system in Heggelbach, the land
underneath the agrivoltaic system was designated a special
use area. The application for agricultural land subsidies was
rejected even though farming was still being carried out.
Further information on approval processes can be foundin section 7.2.

Fraunhofer ISE, together with project partners, has drawn
up a DIN specification to define quality standards that
could serve as criteria for tenders, funding or simplified
planning processes (see section 2.3). These include thedefinition of agrivoltaic indexes and corresponding test
processes that can be used by certifying bodies such as theVDE (Association for Electrical, Electronic and Information
Technologies) or TÜV.

Table 07: Overview of approval steps for agrivoltaics
Process steps

Institution

Comments

Building permit

Municipality

Zoning map and development plan

Required expert opinions

Certified experts

Environmental, soil and glare protection
report. Wind load testing

Recording of the easements (optional)

Insurance

52

NotaryInsurance company

Right of way and ownership structure, forexample Applications submitted throughnotaries

In the APV-RESOLA project, the pilot system
in Heggelbach was insured under the same
conditions as a conventional ground-level
PV system

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

5.7.2

Installing an agrivoltaic system following
the Heggelbach example

Project planning and land use planning are generally handled
by a firm from the solar industry. However, in principle, thefarm can install the system, either on its own or in cooperation
with the local machinery ring.
The technical partners are responsible for all planning andprocesses relating to the construction, installation andoperation of the system. This includes:
finding partners to purchase the excess electricity and feed
it into the gridmaterial procurement and logistics planning
construction site setup and soil protection
system setup
concept for connection, lightning protection and monitoring
grid connection
technical maintenance and removal
In the case of the research system in Heggelbach, thebuilding application was submitted just six months after the
hearing in the Herdwangen-Schönach municipal council.
The building permit was granted one month later. However,building approval was linked to a verification of the statics
by an independent test engineering firm. A soil report wasalso prepared to document the actual retention force of theanchoring. The results of this report and the feedback from thetest engineering firm were incorporated into the revision of theagrivoltaic mounting system.

The various contracts for the installation of the researchsystem were awarded to various firms in accordance with theprocurement regulations, and the construction process wascoordinated in close consultation with the farming community
Hofgemeinschaft Heggelbach. The power electronics and wiringof the system were installed so that the research system could bequickly connected to the grid upon completion.

5.7.3

Agrivoltaics in operation

Because of the crop cultivation and particularly in the caseof stilted, overhead systems, the PV modules are not fully
accessible at all times. Maintenance and repair work should
therefore be carried out when fields are fallow and the land is
not being used for farming. Not all maintenance vehicles are
suitable for working on agricultural land. Workers must be
secured when working at clearance height.
Soil can be churned up while land is being cultivated, leading
to soiling of the PV modules. This is especially true in highwinds and when the soil is particularly dry. Tilling in these
conditions should therefore be avoided as far as possible.

Fig. 59: Construction roads to avoid soil compaction

Fig. 60: Maintenance work on the agrivoltaic system in© BayWa r.e

Heggelbach © Fraunhofer ISE

53

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

6

Society

If the energy transition is to succeed, it must be anchored insociety through social acceptance[29]. There are two aspects tothis: the fundamental approval or rejection of political goals
and concrete measures and the willingness, or lack thereof, ofcitizens to accept concrete local infrastructural measures, suchas the building of ground-mounted PV or agrivoltaic systems.
The German federal government’s target for increasing theshare of electricity generated from renewable energy sources
has the broad approval of the population across technologies.
This is shown by scientific, representative opinion polls carriedout in recent years[30]. The most encouraging response was tothe building of additional solar power systems on the roofs ofhouses, which is supported by 92 percent of respondents[31].
The approval rate for the political target of expanding groundmounted PV systems is 74 percent, which is significantly lower
than in previous years when it was at 80 percent[30].
However, even where the specifications of planning law andlocal policy have been met, the expansion of renewable energy
supply remains controversial and faltering when it comes tofinding suitable sites for building new systems[32]. The buildingof ground-mounted PV systems may be rejected or resistedby the local population, who may criticize the form and sizeof the system and fear that their houses and recreationallandscape will lose their value. Acceptance problems at the
local level arise when decisions are made at particular politicalor economic levels to build new systems in a certain form orin a certain way without adequately taking into account theinterests of the population or the concerns of the community
or giving local people the opportunity to voice their opinions
or be involved. It is therefore no wonder when societal groups
do not accept such decisions, even if they were made following
the proper planning or local policy procedures.

54

There are indications that agrivoltaic systems are generally
viewed in a more positive light than ground-mounted
PV systems because of the dual use of agricultural land.
However, even in the case of agrivoltaic systems it isnonetheless crucially important, even as early as the planningstage, to involve the various stakeholder groups and the
local population with a connection to the planned system.
Developing a shared understanding of the sustainability
targets to be achieved in regional food production, species
conservation, preservation of the farming and leisure landscapeand the decentralized generation, storage and use ofrenewable energy is of particular importance in this context[29].
A transdisciplinary approach helps to take into account thedifferent interests and expectations, but also the different
preferences and concerns, to reduce acceptance problems
and to drive the energy transition forward on site with local
stakeholder groups[33]. This makes it possible to increase
regional willingness to invest and local value creation and to
take into account the interests of the population even before
the decision to build a system is made.
The role of subjective risk-benefit evaluations by the various
stakeholder groups is particularly significant: They leadto concerns about potential financial, health or aesthetic
problems associated with local changes to the environment,
and particularly to land use and the visual landscape[34]. It istherefore the job of investors and project planners to employ
appropriate communication strategies to approach thestakeholder groups in the community at an early stage in orderto keep them informed in a transparent manner and allow
them to have their say.

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

6.1

Engaging citizens and stakeholder groups

Because an agrivoltaic system is a cross-sector enterprise
between the agriculture and energy supply sectors,
communication and dialogue with all those involved, both
directly and indirectly, is absolutely key. When establishing
infrastructure projects, it is important to avoid conflicts ofinterest by involving the (local) population and stakeholder
groups at an early stage. Bringing citizens and stakeholder
groups into the approval process requires a clear framework,and should be based on a shared understanding of the
problems and lead to the joint development of an idea to solve
those problems. The project’s goals should be communicatedclearly and openly to prevent misunderstandings about the roleand process of involving stakeholder groups and citizens[32].
The communication process should allow those involved
to gain a new perspective on individual structures in theiractions, values and preferences: on the one hand the citizens
and stakeholder groups that are in many cases interested inchanging the responsibility and decision-making structuresand in getting involved both politically and financially, andon the other hand the investors and project planners who
are looking for tailored, easy-to-implement, effective andmarketable solutions[32]. An important trust-building measureis the proactive, timely and comprehensive communicationof information about the planned system, the approval
process and the opportunities that exist to speak to investors
and operators in order to get involved in shaping outcomes.
The decisions as to how stakeholder groups and citizens are
addressed and involved and what forms of participation areused need to be tailored to the specific context. This depends
on the combination of players involved and their individual
concerns. The following general rules apply: The earlier
communication begins and dialog is proactively created, thesooner the conditions for success and questions of involvement
can be discussed, examined and resolved.

6.2

Context-specific acceptance

The acceptance of agrivoltaics will be affected by context
factors. These are not directly related to the technology, but
are to related to aspects that shape the context in which theprocess of creating acceptance takes place and that influence
the perception of the issue from the outside by those whoare being asked to accept it. These aspects include the useof technology, social, legal and environmental contexts
and circumstances (physical, cultural, social, economic andagricultural) and sociopolitical and normative conditions(such as guidelines, participation culture and experience, andcredibility of the individuals involved).
Because agrivoltaic systems used with specialized andpermanent crops are usually smaller, they tend to be more
readily accepted by society than systems used in arable
farming. The smaller size and generally lower clearance
heights mean that the negative visual impact is usually lower.
Furthermore, the visual landscape is already impaired in thesecases by polytunnels or hail protection nets. The potential
additional benefit gained from using agrivoltaics above
specialized and permanent crops is the most important driverof potential greater acceptance in the general population. The
added agricultural value could come from various benefits of
the agrivoltaic system, such as the reduction of heat stress oncrops through shading, the reduction of disease and of theneed for chemical pesticides, erosion protection, irrigation
using renewable electricity, greater biodiversity or more stableyields, even in extreme weather conditions such as heatwaves
or hail. The concrete manifestation and visualization of thesebenefits is likely to play a crucial role in increasing the likelihoodof acceptance of agrivoltaic systems among stakeholder groups
and the public.

55

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

6.3

Two examples for dialogue and engagement

6.3.1

APV-RESOLA research project

The APV-RESOLA project, run by the Institute for Technology
Assessment and Systems Analysis (ITAS) at the Karlsruhe
Institute of Technology (KIT), aimed to gather an early
impression of opinions within society and normative value
systems on agrivoltaics in order to identify potential obstacles,
but also conditions for the successful establishment ofagrivoltaics. These conditions served to answer questions
within society about the future of sustainable, decentralizedenergy supply and to produce a design for an agrivoltaic
system that would be accepted by society. Bringing thedifferent citizens and stakeholder groups together at an
early stage to exchange their ideas strengthened the mutual
understanding of interests, values and preferences.

Fig. 61: Citizens’ information workshop in the
APV‑RESOLA project © ITAS

Fig. 62: Model of the agrivoltaic system in
Heggelbach for information workshops© Fraunhofer ISE

56

In concrete terms, the APV-RESOLA project was a multi-stagetransdisciplinary process, conducted on the site of the pilot
system in the Lake Constance region on arable land cultivatedbiodynamically in accordance with the Demeter guidelines, toinvolve citizens and stakeholder groups using different formats
and at various times. Following an information workshop forall stakeholders, all citizens aged 18 to 80 in the immediate
vicinity of the planned agrivoltaic pilot system were asked toindicate whether they wanted to take part in the process.
An open brainstorming session with the stakeholders on
the opportunities and challenges of agrivoltaics then took
place before the system was built, using a model as a basis(see figure 62)[33]. The participants agreed that the effect ofagrivoltaics on regional food production and the leisure andfarming landscape needed to be taken into account, andthat decisions about the locations of systems needed to bemade at the municipal level so that particular local conditions
and region-specific size and concentration criteria could beconsidered[34]. This first citizens’ workshop was followed bya tour of the pilot system and a survey when the system was
opened. One year after the system was put into operation,
those who had participated in the first workshop were invitedback. The aim of the second citizens’ workshop was to analyze
possible changes in opinions and approval patterns. Someparticipants confirmed their rejection of the system, which
they found obtrusive. “I don’t like it at all. I don’t think anenormous structure belongs in the middle of the countryside.
As a pilot system of this size, I don’t have a problem with it.
You can imagine that. But when I imagine it on a large scale
somewhere, I just can’t get my head around that.” On theother hand, some other participants were positively surprised
and their initial concerns had been put into perspective.

Agrivoltaics: Opportunities for Agriculture and the Energy Transition“Well, standing underneath it, it doesn’t seem so massive tome, more light and airy. It doesn’t feel like an industrial system
to me now.” However, the time frame for assessing the system
was seen as too short. “Many years would be needed until
clear consequences of agrivoltaics could be seen.”
In the second citizens’ workshop, selection criteria forchoosing a site for an agrivoltaic system were also developed.
These include restrictions — factors that restrict or prevent
use — as well as preferential aspects in favor of or enabling
the use of a system. These criteria were applied by participants
to identify suitable sites for agrivoltaics in the HerdwangenSchönach municipality in the Lake Constance region, forexample. This planning exercise allowed participants to workout the context-specific and complex interdependencies forthemselves and to verify the practicality of the criteria that
had been developed in a realistic setting (see figure 63).
This resulted in recommendations for action on politicalmanagement of land use for ground-mounted PV andagrivoltaics. “Regulations need to be adopted to stop land
from being leased to energy suppliers at higher prices so thatfarming can actually continue to be practiced under thesesystems.” Some aspects were identified as key success factors
and implemented at the trial stage. One prominent example isthe increased resource efficiency gained through local storage
and use of the power generated (see more in section 6.4). “If
I don’t have a storage concept, then I needn’t bother setting
up solar systems. That’s the biggest problem. Storage. If we
had storage, it would be fine right away.”
The results and recommendations for action from the second
citizens’ workshop have been discussed in a workshop
with stakeholder representatives. The participants included
representatives from technological development companies,
the energy sector and energy cooperatives, municipal,
regional and state administrations, agriculture, conservationand tourism, as well as representatives of the general public.
A criteria-oriented and open process to identify potentialsites is seen as crucial for regional land use for solar farms
or agrivoltaics. “The land and rural areas should not just be

INFORMATIONWORKSHOP

CITIZENS’ WORKSHOP 1

CONSTRUCTION OFPILOT AGRIVOLTAICSYSTEMSURVEYCITIZENS’ WORKSHOP 2

STAKEHOLDER
WORKSHOP

Fig. 63: Multi-stage transdisciplinary agrivoltaic research approach© ITAS

viewed as cheap energy suppliers for urban areas. It should
be clear where it’s necessary and where it isn’t. Are sloping
sites or biotopes an issue? We don’t want to have the same
uncontrolled growth as we do with biogas systems.” It is
important to have proactive, timely and open communication
on planned projects and to involve citizens locally. “If thecitizen is involved in the project, not just a little bit, but if
it’s a citizens’ project, then the project has a greater chanceof becoming a reality.” There is a lot of concern and “fearthat enormous areas will be built over” and the familiar andbeloved natural and leisure landscape in people’s backyards will
be changed for the worse. “I find it paradoxical that people saythat wind bothers people and disrupts tourism and then theymight authorize a ten-hectare stretch of agrivoltaics.”

57

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

6.3.2

APV Obstbau research project

Another example of early involvement of stakeholder groups
is the APV Obstbau (Agrivoltaic Orcharding) research projectin the district of Ahrweiler in Rhineland-Palatinate. For
a technological innovation like agrivoltaics to succeed, it
requires the support not only of the population, but also of
all stakeholders involved in the implementation of a system.
The aim of the qualitative analysis was therefore to obtaina subjective picture of the sentiments surrounding the factorsthat helped or hindered support for agrivoltaics. To achievethis, a survey was conducted alongside the implementationof the agrivoltaic research system to interview representatives
from administration, the energy sector, environmental andspecies conservation associations, the agriculture sector,
farmers’ associations, local politics and science. The content
of the interview questions addressed knowledge of the APV
Obstbau project, perceptions of agrivoltaics and estimationsof the opportunities, challenges and future prospects ofagrivoltaics.
As a result, there was a predominantly positive attitude acrossall stakeholder groups toward agrivoltaics for the orcharding
region, its future and the research project. The responses
to the interview showed that the acceptance of agrivoltaics(as is generally the case with renewable energies) is highly
dependent on regional conditions[5]. In the region of the APV
Obstbau research project, plastic films and hail protection nets
in orcharding have been in use across large areas in orcharding
for many years. The familiar view of a farming landscapewith structures built over it favors the aesthetic perception oftechnical structures like agrivoltaics, particularly if they haveadditional synergy effects. These include, in particular, dual
land use for food and energy production, financial profits
for farmers and positive environmental effects. The crop
protection factor of agrivoltaics is also important for farmers.
The main factors hindering acceptance are uncertainties
surrounding the economic viability of agrivoltaic systems,
integrating them into modern agricultural work management
and the current legal framework for constructing them.
For species and environmental conservationists, any negativeenvironmental impacts that may arise must also be viewed
with criticism where possible. Based on the estimation of
the local stakeholders involved, concrete communication
concepts specific to the various stakeholder groups can thenbe developed for the circumstances in the Ahrweiler district.
Although the results of such studies are tied to the region
and the context, the resulting findings and communication
concepts can serve as a template for future projects.

6.4

The transdisciplinary research carried out in the APV-RESOLA
project has the following key success factors for social
acceptance of the use of agrivoltaics, confirmed from theviewpoint of the current status of the APV Obstbau project:
Expansion strategy
1.	 Using the existing potential of PV on rooftops, industrial
buildings and parking lots should take priority overidentifying sites for agrivoltaic systems.
2. The systems should be set up on sites where the dual use of
the land will give rise to synergies, for example from using
the resulting shade to reduce heat stress on crops or the
supply of power for irrigation or digital land managementwith electrified and, in the future, autonomous systems.
Production of food and energy
3.	 Agricultural use of the land to produce food underneathagrivoltaic systems should be mandatory in order to preventthe unilateral optimization of power generation and“pseudo-farming” underneath the PV modules.
4. The systems should be integrated into a decentralizedenergy supply in order to use the solar power on site orfor processes with higher value creation such as irrigation,
cooling or processing agricultural products.
5.	 The systems should be combined with an energy storage
system to increase resource efficiency so that the available
electricity can be used to meet local demand.
Integration into the leisure and farming landscape
6.	 The size and concentration of the systems should be
limited and, as with wind farms, minimum distancesfrom residential areas should be defined in view of local
site characteristics and societal preferences. In order tomanage the number of systems in regions that are used
for agriculture, regional land use policy should manage
the approval of agrivoltaics, for example by limiting sitecoverage levels1.
7.	 Agrivoltaic systems must not negatively alter the qualityof local and regional recreation or the visual landscape.
Sites that are naturally shielded from view (on the edges offorests, for example) or flat sites should be given preference
in order to integrate the systems into the landscape in thebest way possible.

1

58

Success factors

Standard for the building site types in the Land Utilization Ordinance(Baunutzungsverordnung, BauNVO).

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Ecological contribution
8.	 Where the systems have strips of land that cannot be
farmed, these should be used as erosion protection strips
or corridor biotopes to maintain or increase biodiversity inagriculture.

Fig. 64: Where agrivoltaic systems produce strips that cannot
be farmed, these could be used to increase biodiversity on the
agricultural land © Fraunhofer ISE

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Agrivoltaics: Opportunities for Agriculture and the Energy Transition

7

Policy and legislation

Written by Jens Vollprecht, attorney, graduate of forest
management studies, Becker Büttner Held PartGmbB
According to the provisions of the German Federal Climate
Change Act (Klimaschutzgesetz, KSG), greenhouse gas
emissions need to be reduced to the point of net greenhousegas neutrality by 2045. After 2050, greenhouse gas emissions
should be negative. The coalition agreement between theSocial Democratic Party (SPD), the Greens (Bündnis 90/Die
Grünen) and the Free Democratic Party (FDP) states that
80 percent of gross energy needs will be met using renewableenergies in 2030. The scenarios for achieving these goals
assume that PV needs to be expanded to up to 500 GWp[2].
This is approximately ten times the currently available PV capacity.
A considerable share of PV expansion is expected to be
ground-mounted, since this is where PV is currently mostcost-effective.
However, the expansion of ground-mounted PV systems goesagainst the political goal of reducing the amount of land used,which stipulates that new land used for settlements and traffic
needs to be reduced to 30 hectares per day by 2030 and to net
zero by 2050. This is intended in part to conserve fertile soil forfood production. At present, around 56 hectares of land per
day is allocated for settlements and traffic in Germany. This isequivalent to around 79 soccer pitches. As well as PV systems
on roofs, facades, sealed areas, lakes created in former mining
areas and parking lots, agrivoltaics could also help to generateenergy in a space-neutral and environmentally friendly way.

60

Unless a suitable legal framework is created, however, it will bedifficult to establish agrivoltaics in Germany in an economically
viable way for the foreseeable future.
Agricultural subsidies, regulatory approval aspects and financial
support under the Renewable Energy Sources Act (EEG) are
crucially important in the heavily regulated agricultural andenergy sectors. This is particularly the case because agrivoltaics
is a new technology that has had little time to accumulate
learning effects and economies of scale, but that nonethelesshas to compete with established technologies.
To study agrivoltaics further and increase its potential, it
therefore appears prudent, in addition to further research
projects, to implement operational sites close to the market.
This will allow insights into the acceptance, economic viability
and diverse areas of use of the technology to be gained handin hand with agriculture and solar power companies. Germany
has the opportunity to learn from the experience of France andother countries and to pave the way for further developmentof the technology with suitable funding instruments.
Below is an overview of the key aspects of the legal
framework. It is not possible to examine all the legal aspects
and possible combinations of cases here. Ultimately, eachcase needs to be examined and evaluated individually. It isalso important to bear in mind that in many cases no caselaw has been established in relation to the issues raised, so
the positions taken may be subject to legal uncertainty. It istherefore advisable to obtain legal advice when planning anagrivoltaic project.

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

7.1 EU direct payments

7.2 Requirements of public-sector construction law

Within European agricultural policy, business owners receive
direct payments for land that is primarily used for agricultural
purposes, provided that the appropriate requirements are
met. An important question, therefore, is whether a plot of
agricultural land will lose its eligibility for financial support if itmakes use of agrivoltaics.

From the perspective of building regulation law, agrivoltaic
systems are structural installations, so a building permit isgenerally required. A building permit is issued provided thatthe project does not conflict with any regulations underpublic law. If systems do not require a permit, they must still
comply with regulations under public law. The regulations
under public law that must be followed include those underconstruction planning law in particular. Permissibility underpublic law is based on whether the property falls within thescope of a development plan (section 30 of the German
Building Code — Baugesetzbuch, BauGB), in the inner area
(section 34 BauGB) or in the outlying area (section 35 BauGB).

The German CAP Direct Payments Ordinance(GAP‑Direktzahlungen‑Verordnung, GAPDZV) has been
established as one way to implement the numerous European
requirements in relation to the Common Agricultural Policy.
In line with this ordinance, the loss of eligibility describedabove does not arise if the system is an agrivoltaic system.2
An agrivoltaic system is defined in section 12(5) sentence 1 of
the GAPDZV as a system for the use of solar radiation energythat is constructed on agricultural land and does not preventthe land from being cultivated using conventional agricultural
methods, machinery and equipment and does not reduce theusable agricultural land by more than 15 percent on the basisof DIN SPEC 91434:2021. Provided that the requirements aremet, 85 percent of the land is considered eligible for financial
support, broadly speaking.3
This new regulation is to be welcomed as it removes theuncertainty that resulted from the previous regulation. There
were very good arguments that the general loss of financial
support when constructing a solar PV system on the land
was not compliant with European law. Rather, the financial
support was to be granted if the use of the land for agricultural
purposes was not severely restricted by the operation of thesolar PV system.4 It is also possible to gain this understanding
when “reading into” section 12(5) sentence 1 no. 1 of the
GAPDZV, meaning that sheep grazing on the land can beseen as “land being cultivated using conventional agricultural
methods,” for example. As the land that cannot be used for
agricultural purposes is often much less than 15 percent,particularly in the case of stilted, overhead systems, theoperator should be given the opportunity to obtain financial
support for more than 85 percent of the land, provided thatthe operator can prove this to be the case. This could beachieved by adding sentence 3 below to section 12(5) of
the GAPDZV: “If the operator demonstrates that the system
reduces the land that can be used for agricultural purposes byless than 15 percent on the basis of DIN SPEC 91434:2021,
the land that is eligible for financial support in accordance withsentence 2 increases accordingly.”2

See section 12(4) no. 6 GAPDZV.

3

See section 12 V sentence 2 GAPDZV.

4

For more information, see Vollprecht/Kather, IR 2022, 232 (233).

Building permit

Local building
authority

Participationof authorities:
nature conservation,
environmental
protection, water
management,
agriculture, etc.

Additionalrequests canbe madeCompletenesscheck

Municipality
participation
Community
participation

Reliability check

Building permit

Start ofconstruction

Fig. 65: Example process for a building application© Fraunhofer ISE

61

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

7.2.1

Outside the scope of a development plan

If the property is not located within the scope of a development
plan, permissibility under construction planning law depends
on whether the project is in the inner area as per section 34
BauGB or in the outlying area as per section 35 BauGB. The
land that comes into consideration for the implementationof agrivoltaic projects is typically located in the outlying area.
For this reason, section 34 BauGB is not considered here.
Explicit privilege for agrivoltaic systems has recently been
introduced in section 35(1) sentence 1 no. 9 BauGB: In thiscase, it must be noted that the system must meet therequirements of a special solar PV system in accordance withsection 48(1) sentence 1 no. 5 (a), (b) or (c) of the German
Renewable Energy Sources Act 2023 (Erneuerbare-EnergienGesetz, EEG). As such, the requirements stipulated by theFederal Network Agency (Bundesnetzagentur, BNetzA) and the
DIN SPEC mentioned above play a key role.5 In addition, theproject must have a spatial and functional relationship witha business in accordance with section 35(1) no. 1 or 2 BauGB,
the area of the special solar PV system must not exceed
25,000 square meters, and only one system must be operated
per business or facility.
In addition, projects have been included in section 35(1)sentence 1 no. 8(b) BauGB that are intended for the use ofsolar radiation energy and are constructed on land along
highways or railroad tracks in the higher-level network inaccordance with section 2b of the German General Railway
Law (Allgemeines Eisenbahngesetz) with at least two main
tracks and at a distance of up to 200 meters from these,measured from the outer edge of the road or track. Agrivoltaic
systems are projects that use solar radiation energy, so these
may be classified as privileged projects in the context describedabove.

A project may be considered privileged if it serves agriculturalor forestry activities and occupies only a minor proportion of
the land (section 35(1) sentence 1 no. 1 BauGB). Agriculture asa term is legally defined in section 201 BauGB. Special attention
should be given to the term “serving.”6 In general, the systems
required to supply energy to the business’s buildings meet thisrequirement provided that the proportion of electricity used onsite primarily serves the business and has a spatial relationshipwith the same. The business-related proportion of the energy
generation measured on the basis of the total capacity of thesystem must carry significant weight. If the business-related
proportion does not considerably exceed the amount ofenergy intended for the public grid, the system may fail tomeet the definition of the term “serve.” The German Federal
Administrative Court has deemed the use of approximately
two thirds of the electricity generated in a wind farm in an
agricultural business to be adequate.7 In view of climatechange and the future requirements in agriculture and forestry
or horticulture (including protection against hail, heavy rain,strong solar radiation), and assuming an appropriate designof the solar PV systems, the serving function in accordancewith section 35(1) sentence 1 no. 1 BauGB derives from theirprotective function for crops, soil and the water regime. In otherwords, low on-site consumption of the electricity would be no
barrier to classification as a privileged project in this case.8 The
circumstances relating to privilege in accordance with section
35(1) no. 2 BauGB, which state that a project that servesa horticultural business is also considered to be a privileged
project, should also be mentioned here. A critical examination
would of course need to be made in individual cases withregard to section 35(1) sentence 1 no. 1 BauGB to determine
whether only a minor proportion of the land is occupied. In thecontext of section 35(1) sentence 1 no. 2 BauGB, this additional
requirement does not play a role.

If the agrivoltaic system is constructed on another type ofland, the amount of work involved in providing justification
for classification as a privileged project may be significantly
increased. However, there are various other circumstances
relating to privilege that may come into consideration
depending on the nature of the project.

5

For more information, see below in section 7.4.3.

6

For information on the term “serving,” see German Federal Administrative Court, decision of November 3, 1972 — 4 C 9.70.

7

See German Federal Administrative Court, decision of November 4, 2008 — 4 B 44.08.

8

See Vollprecht/Kather, IR 2022, 232 (234); Attendorn, Klima schützen und Energiesicherheit schaffen, 2022, p. 102 f.; different interpretation Frey/Ritter/Nitsch,
Neue Zeitschrift für Verwaltungsrecht (NvWZ) 2021, 1577, 1578, who express concerns under constitutional law due to their belief that privilege for groundmounted systems in outlying areas is lacking.

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Agrivoltaics: Opportunities for Agriculture and the Energy Transition

7.2.2

Establishing a basis under planning law

If permissibility for a project in outlying areas not covered bya development plan is not possible, the land can be “moved”
into an area covered by a development plan. This is achieved by
setting up a development plan for the land. The development
planning authorities are able to use several instruments for thispurpose.
When it comes to issuing a simple or qualified development
plan, the numerus clausus principle in accordance withsection 9 BauGB must be observed. In accordance with
this, the municipality is not entitled to designations thatcannot be supported on the basis of section 9 BauGB or
the Land Utilization Ordinance (Baunutzungsverordnung,
BauNVO). For example, a basis under planning law can beestablished by designating a special area in accordancewith section 11(1), (2) BauNVO. This stipulates that an area
intended for systems that are used for research, development
or use of renewable energies — such as wind and solar
energy — is considered to be a miscellaneous special area.
The problematic factor here is that designating it solely asa special solar area may not sufficiently take account of the
agricultural use of the area. It therefore appears advisable todesignate the area simultaneously as land for agriculture under
section 9(1) no. 18(a) BauGB. It has been acknowledged thatdesignations under section 9 BauGB may overlap for individual
areas of land, meaning they can mutually complement one
another. It is not possible to have different designations for thesame area of land if these designations are mutually exclusive.
However, agrivoltaic systems guarantee the implementationof different requirements on the same land, meaning these“dual” designations are possible. A further consideration isto select “special area for agrivoltaics” as the designation.
These designations must be supported by appropriate written
descriptions.
If a project-related development plan is issued in accordancewith section 12 BauGB, it would also be possible to make useof the scope afforded under planning law, as the authority canpermit the project in this case without any strict considerationof the numerus clausus principle.

97.3

Inheritance tax, gift tax, property tax
and land transfer tax

If a ground-mounted system is constructed on an area ofland, there is a risk that this land will be allocated to landed
property, rather than agricultural and forestry activities. Thismeans that the benefits for agricultural and forestry property
in relation to inheritance tax, gift tax, property tax and landtransfer tax would no longer apply — and this may even be
the case retrospectively if the retention periods after the farmtransfer have not yet elapsed.
According to the identical decrees of the highest tax authoritiesof the states regarding the assignment and assessment ofagrivoltaic systems dated July 15, 20229, the following rule
applies for the purposes of property tax, inheritance tax, gift
tax and land transfer tax: Land on which solar PV systems
are constructed that are category I or II agrivoltaic systems
in accordance with DIN SPEC 91434 must be allocated toagricultural and forestry property. Land on which PV systems
are constructed that are not category I or II agrivoltaic
systems in accordance with DIN SPEC 91434 (particularly
ground‑mounted systems) must be allocated to landed
property. This makes it clear that the benefits apply only
to certain agrivoltaic systems, and not all ground-mounted
systems.
However, it should be noted here that design options areavailable to avoid the disadvantages described above even
if the system does not satisfy the requirements stipulated
in DIN SPEC 91434.
It should also be noted that a special rule applies in Bavaria.
According to art. 9(3) of the Bavarian Property Tax Law(Bayerisches Grundsteuergesetz, BayGrStG), taxation on thebasis of the more favorable Property Tax A is possible in spiteof the transfer of the land previously allocated to agriculturaland forestry property for the operation of ground-mounted
PV systems provided that an asset retirement obligation withsubsequent continuation of the agricultural and forestry use
has been contractually agreed.

Federal Tax Gazette (Bundessteuerblatt, BStBl) I 2022 p. 1226.12 particularly section 9 BauGB.

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Agrivoltaics: Opportunities for Agriculture and the Energy Transition

7.4

Renewable Energy Sources Act 		
(Erneuerbare‑Energien-Gesetz) 2023

The following section refers to the German Renewable Energy
Sources Act 2023 (EEG) in the version dated July 26, 2023
(Federal Law Gazette (BGBl.) 2023 I no. 202). Within theframework of the German government’s “Solar Package I,”
a draft law will be ready by the end of August 2023 thatprovides for extensive changes in relation to the funding ofagrivoltaics, including establishing a separate tender segment
for stilted, overhead agrivoltaic systems10. Once the change inthe law has passed through parliament and been published in
the Federal Law Gazette, an updated version of this guideline
will be drafted.
Agrivoltaic systems generate electricity from solar radiationenergy and should therefore be classified as “entirely normal”
systems for generating renewable energy in accordance withsection 3 no. 1 EEG 2023.

7.4.1

Grid connection and allocation of costs

Operators of these systems are therefore entitled to priority
grid connection from the operator of the general supply gridin accordance with section 8(1) EEG 2023. EEG 2023 also
specifies the point at which the system should be connected to
the grid. The priority here is to limit the economic costs: This
involves identifying the grid connection option with the lowest
total economic cost. Only once this option has been identified
does it become clear which party has to bear which costs.
Here, the following applies: The system operator must bear thegrid connection costs, while the grid operator must bear thegrid expansion costs.11

7.4.2

Purchasing of the electricity

In addition, the operator of the agrivoltaic system is entitled
to claim priority purchase of the generated electricity from thegrid operator in accordance with section 11(1) EEG 2023. Inother words, the grid operator is only allowed to prohibit thefeeding of electricity into the grid in exceptional cases. Thisis true in the case of Redispatch 2.0, for example; but in thiscase, the system operator is entitled to claim compensation forelectricity not fed into the grid.12
However, the system operator is not obliged to feed theelectricity into the grid, and can use it on-site or supply it toa third party instead “before” it is used in the grid.13

7.4.3

Financial support

The matter becomes more complex with regard to funding inaccordance with EEG 2023 for the electricity fed into the grid.
EEG 2023 has resulted in many positive changes for agrivoltaic
systems in this regard.
Mandatory direct marketing, participation in tenders andfunding period
Firstly, it must be noted that operators of systems with an
installed capacity of more than 100 kWp14 are obliged tomarket the electricity to a third party (known as mandatory
direct marketing).15 However, this does not mean that thegrid operator must make no payments in this instance: In
the case of funded direct marketing, the system operator isentitled to claim a “market premium” from the grid operator
in accordance with section 20 EEG 2023. This is the difference
between the reference value16 and the annual market value forsolar energy.17 Since the electricity is being sold to a third party

10 See the joint press release from three Federal Ministries (Economic Affairs and Climate Action (BMWK), Food and Agriculture (BMEL) and Environment, Nature
Conservation, Nuclear Safety and Consumer Protection (BMUV)), available at https://www.bmwk.de/Redaktion/DE/Downloads/Gesetz/20230816-gemeinsamespressepapier-photovoltaik.pdf?_blob=publicationFile&v=10
11 See section 16(1); section 17 EEG 2023.
12 For more information, see Lamy/Lehnert, EnWZ 2021, 208 et seq.
13 Because the general supply grid is not used under this arrangement, grid charges are not incurred. The same applies to grid charges and levies (such as thecogeneration levy, the levy under section 19(2) of the Grid Charges Ordinance (StromNEV), the offshore grid levy or the concession fee). For example, the system
operator can therefore offer the supplied party a more favorable price for the electricity than a supplier who supplies via the grid. The EEG levy will no longer apply
in future as it is to be abolished on January 1, 2023. However, electricity tax still needs to be observed, though in this case the exemption conditions in accordancewith section 9(1) no. 1 and 3 of the German Electricity Tax Law (Stromsteuergesetz, StromStG) can open up some potential optimizations.
14 When determining the size of the system in this case and also thereafter, the “system combination rules” under section 24(1) and to some extent (2) EEG 2023
must usually be observed.
15 This can be deduced from section 21(2) no. 2 EEG 2023, which states that the system operator can sell electricity to the grid operator but will only receive the low
fall-back feed-in tariff in this case. This low feed-in tariff is intended to encourage the system operator to switch back to direct marketing as soon as possible.
16 The reference value is an amount in cents per kilowatt-hour.
17 See no. I.2. Appendix 1, EEG 2023.

64Agrivoltaics: Opportunities for Agriculture and the Energy Transition

and this third party is paying the agreed price to the system
operator, the operator therefore receives a total of the market
premium and the price agreed with the direct marketer in thecase of funded direct marketing for electricity fed back into
the grid.
If the system’s capacity is below the 100 kWp threshold, the grid
operator is obliged to purchase the electricity. The operator
then receives the “feed-in tariff” from the grid operator. The
feed-in tariff is calculated on the basis of the reference value,
from which 0.4 ct/kWh is deducted in the case of fluctuating
renewable energies, such as agrivoltaics.18 However, it is also
possible for the operator to switch to another form of selling,such as funded direct marketing.
Operators of agrivoltaic systems with an installed capacity ofmore than 1000 kWp19 must successfully take part in a tenderfor first-20 or second-segment21 solar PV systems under section
29 et seq. in conjunction with section 37 et seq. or 38c etseq. EEG 2023. An exception to the mandatory tender may
apply if the agrivoltaic system is operated by a “citizen energy
community” in accordance with section 3 no. 15 EEG 2023:
In this case, the level at which participation in a tendermust take place is increased to 6000 kWp.22 It may therefore
make sense to establish a citizen energy community for thisreason, alongside the aim of increasing the acceptance of theagrivoltaic project. System operators cannot claim financial
support from the grid operator under the EEG unless they
have a surcharge or, in the case of first-segment systems,
a “payment entitlement.”23

Section 27a has been abolished.24 This should be seen as
a positive step, as integrating agrivoltaics into agriculture
has highlighted the fact that it is essentially ideal in terms ofmeeting farms’ demand for electricity. If the electricity is not
used on-site “before” it is used by the grid, it can be fed into
the grid and financial support can be claimed for this in the
future.
For ground-mounted systems, the “20 MWp limit” definedin section 38a (1) no. 5 EEG 2023 also needs to be taken
into account: Any capacity the system may have in excessof this limit is not eligible for subsidy. As an exception, thislimit is increased to 100 MWp in the case of a bidding date in
2023.25 For second-segment systems, the size per bid must
not exceed 20 MWp.26
Financial support is paid for 20 years from the time at which
the system is commissioned.27 For systems with financial
support that is defined in law, payment is extended until
December 31 of the twentieth year. It should be noted that
entitlements to claim grid connection and purchase of theelectricity are not time-limited, meaning they are perpetualrights.
Requirements for financial support
In addition to the general requirements for financial support
under the EEG 2023, there are special requirements relating
to solar energy that must be met. These are outlined but notdescribed in full below.

18 See section 21(1) no. 1 in conjunction with section 53(1) no. 2 EEG 2023.
19 See section 22(3) sentence 2(a) EEG 2023.
20 Ground-mounted systems and solar PV systems installed on or in structural facilities that are neither buildings nor noise barriers; see section 3 no. 4a EEG 2023.
21 Solar power systems to be installed on or in a building or noise barrier; see section 3 no. 4b EEG 2023.
22 See section 22(3) sentence 2(b) EEG 2023.
23 See section 22(3) sentence 1 EEG 2023.
24 In principle, it was not previously possible for electricity from systems subject to the tendering procedures to be used to supply power directly to the operator.
In the event of breaches, the reference value for the entire calendar year in which the breach occurred was reduced to zero; see section 52(1) no. 4 in conjunction
with sentence 3 EEG 2021.
25 See section 100(13) sentence 1 EEG 2023.
26 See section 38c(2) EEG 2023
27 See section 25(1) EEG 2023; see also section 51a EEG 2023.

65

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Systems on buildings or other structural facilities
As specified in section 48(1) no. 1 EEG 202328, a system is
eligible for financial support if it is installed on or in a building
or other structural facility that was built primarily for purposes
other than the generation of solar power. Essentially, thismeans that the solar power system should be installed ona surface that is being used “anyway” (“dual use”).
The PV system may also be installed as a roof.29 In the caseof PV systems on greenhouses, for example, it must be
ensured that the use of the greenhouse focuses mainly on
its actual function. There is no barrier to financial support
if the building structure for supporting and operating theenergy-generating systems — as well as with regard to
any compensation to be obtained in accordance with the
EEG — undergoes a certain amount of optimization withregard to its stability and durability, even if these measureswould not otherwise have been strictly necessary in termsof achieving the primary purpose of the structural facility.30
As a result, a close examination of the individual case isrequired. For non-residential buildings in outlying areas notcovered by a development plan under section 35 BauGB, suchas greenhouses, the restriction in section 48(3) EEG 2023
must also be observed. In the case of rooftop systems witha capacity of up to 1000 kWp, the financial support available
is increased if — in simplified terms — all of the electricity
generated is fed into the grid and not simply the “surplus.”31
In cases where the system is not installed on a building, it must
be determined whether the system may be constructed onanother type of structural facility. If, for example, the structure
in question is a trellis for hops to which the module is merely
attached, it is possible to make a good argument since thetrellis is constructed to allow the hops to grow upward, i.e.,
for purposes other than generating solar energy. It should
be possible to apply the considerations of the Federal Courtof Justice (BGH) mentioned above regarding optimization ofstability and durability to this configuration. In other words,
a certain amount of reinforcement of the trellis would be no
barrier to financial support in accordance with section 48(11)no. 1 EEG 2023. The same applies to trellises in orcharding
and vineyards, but careful consideration of individual cases isrequired here too.
Ground-mounted system
If the requirements of a building or other structural facility
are not met, eligibility for financial support may also bebased on section 48(1) no. 3 EEG 202332: In these cases, anagreed development plan must generally33 be available forthe land, which also — and this is a new stipulation — mustnot be drained, marshy soil used for agricultural purposes34.
If that development plan was established or amended after
September 1, 2003 for the purpose of constructing a solar
power system, the agrivoltaic systems must be located inparticular areas, for example along highways or railroad tracks
within a 500 meter strip measured from the outer edge of the
fixed road or track35 or in a “conversion area.”In the case of ground-mounted systems, payment entitlementin accordance with section 38a(1) no. 5(b) EEG 2023 may
only be issued if the system is not located on land that was
legally defined as a nature conservation area in accordancewith section 23 of the Federal Nature Conservation Act(Bundesnaturschutzgesetz, BNatSchG) or as a national park inaccordance with section 24 BNatSchG at the time the decision
to establish or amend the development plan was made.
New additions to the EEG that are to be welcomed are thethree different conditions for funding in section 37(1) no. 3(a)to (c) EEG 2023 and section 48(1) no. 5(a) to (c) EEG 2023
for certain agrivoltaic systems.36 In each case, the following
requirements (among others) must be met: According to (a) in
the regulations, systems on arable land with simultaneous crop
cultivation on the same land are funded37 (arable agrivoltaics)38.

28 In the case of systems subject to the tendering procedures, this is based on section 38c(1) EEG 2023 or section 37(1) no. 1 EEG 2023
29 Regarding the EEG, see 2004 Federal Court of Justice (BGH), verdict of November 17, 2010 — VIII ZR 277/09.
30 Regarding the EEG, see 2004 Federal Court of Justice (BGH), verdict of November 17, 2010 — VIII ZR 277/09.
31 See section 48(2), (2 a) EEG 2023.
32 In the case of systems subject to the tendering procedures, this is based on section 37(2) no. 2(c) EEG 2023.
33 This does not apply in exceptional cases in accordance with section 37(1) no. 2(c) EEG 2023 if the requirements specified in section 35(1) no. 8(b) BauGB are met(see above for more information).
34 According to section 3 no. 34a EEG 2023, marshy soil is any soil that meets the requirements of section 11(2) of the German CAP Conditionality Ordinance(GAP‑Konditionalitäten-Verordnung, GAPKondV) and that can be used as the basis for the area classification in accordance with section 11(3) GAPKondV.
The fact that it may not be possible to classify an area of land with legal certainty on the basis of the listed criteria is problematic. It would therefore be desirable
if the BNetzA were obliged to designate these areas of land as marshy soil in a definition with legal certainty.
35 The strip was previously limited to 200 m and a corridor 15 m wide had to be kept clear within this strip; see section 37(2) no. 2 EEG 2021 or section 48(1) no. 3
EEG 2021.
36 In the case of systems subject to the tendering procedures, this is based on section 37(1) no. 3(a) to (c) EEG 2023.

66

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

To claim the funding in accordance with (b), the systems must
be constructed on land with simultaneous agricultural use in
the form of cultivation of permanent crops or perennials on thesame land39 (crop agrivoltaics)40. At the last moment, (c) was
added: This provides for funding of systems on grassland withsimultaneous agricultural use as permanent grassland provided
the land is not located on a Natura 2000 site in accordancewith section 7(1) no. 8 BNatschG and is not a habitat
type listed in Annex I of Directive 92/43/EEC (grassland
agrivoltaics)41. The land must not be classified as marshy soil.
It should also be highlighted that the land does not need to
be located within an agreed development plan.42
If these agrivoltaic systems are stilted to a total clearance
height of at least 2.1 meters, the reference value is increased
to include a technology bonus, which is 1.2 cents/kWh fora tender awarded in 2023 and reduces incrementally to
0.5 cents/kWh for tenders awarded in 2026 to 2028.43
This bonus is to be welcomed but should be increased
significantly since the additional cost of the stilts is so highthat they are generally not covered by the bonus amount. As
a result, there are fears that these stilted, overhead systems will
not be implemented. It is conceivable that the Federal Network
Agency (Bundesnetzagentur, BNetzA) could be granted
powers to increase this value. Similar powers are granted tothe authority in section 85a EEG 2023. Another option would
be to establish a separate tender segment for these stilted,
overhead agrivoltaic systems with a much higher maximum
value than that currently provided for first-segment solar
PV systems. The additional costs would then be determinedin a competitive process.
In addition, the technology bonus is only granted if the system
operator has successfully participated in the tenders for firstsegment solar PV systems. This is based on the reference to“special solar PV systems in accordance with section 37(1)

no. 3(a), (b) or (c)” in section 38b(1) sentence 2 EEG 2023.
As a result, this bonus cannot be claimed for systems witha level of financial support that is determined in law. This
is not comprehensible since additional costs for stilts are
incurred in this size class too. There is no obvious material
reason for such unequal treatment. Sentence 3 below should
therefore be added to section 48(4) EEG 2023: “Section
38b(1) sentence 2 should be applied with the stipulation that
it is not the award of the tender that is used as the basis but
the time at which the system is commissioned.”
A further category of special solar PV systems is marsh
PV in section 37(1) no. 3(e) EEG 2023.44 In this case, theprerequisite for financial support is that the systems areconstructed on marshy soil that has been drained and used
for agricultural purposes, and that the land will undergo
permanent rewetting following construction of the solar
PV system. In this case too, the land does not need to belocated within the scope of a development plan. Section
38b(2) sentence 3 EEG 2023 provides for a “marsh bonus”
of 0.5 cents/kWh. However, in this case too, this bonus
cannot be claimed for systems with a level of financial
support that is determined in law. Once again, there is no
obvious material reason for this. For this reason, in section
48(4) sentence 1 EEG 2023, “and sentence 3” should be
added after “sentence 1” and the “is” should be replacedwith “are.”
The details regarding these special solar PV systems are
specified in a definition by the BNetzA in accordance withsection 85c EEG 2023. In the context of arable agrivoltaics
and crop agrivoltaics, the definition by the BNetzA dated
October 1, 2021 is to be applied.45 With regard to grassland
agrivoltaics and marsh agrivoltaics, the relevant definition
has now been issued.46 A positive development is thata stipulation has been made in the context of marsh PV
whereby the additional paludiculture is a permissible

37 It should be noted here that when submitting the bid, the tenderer must submit a self-declaration stating that they have checked that the land is not arable landwith relevance to nature conservation. (see section 37(2) no. 3 EEG 2023). It is unclear what requirements in relation to financial support can be derived from this.
38 For systems with a reference value that is determined in law, the land must not have been legally defined as a nature conservation area in accordance with section
23 of the Federal Nature Conservation Act (Bundesnaturschutzgesetz, BNatSchG) or as a national park in accordance with section 24 BNatSchG (see section 48(1)no. 5(a) EEG 2023)
39 It should be noted here that when submitting the bid, the tenderer must submit a self-declaration stating that they have checked that the land is not arable landwith relevance to nature conservation. (see section 37(2) no. 3 EEG 2023). It is unclear what requirements in relation to financial support can be derived from this40 For systems with a reference value that is determined in law, the land must not have been legally defined as a nature conservation area in accordance with section
23 of the Federal Nature Conservation Act (Bundesnaturschutzgesetz, BNatSchG) or as a national park in accordance with section 24 BNatSchG (see section 48(1)no. 5(b) EEG 2023).
41 For systems with a reference value that is determined in law, the land must not have been legally defined as a nature conservation area in accordance with section
23 of the Federal Nature Conservation Act (Bundesnaturschutzgesetz, BNatSchG) or as a national park in accordance with section 24 BNatSchG (see section 48(1)no. 5(c) EEG 2023).
42 This is a fundamental difference when compared to the requirements relating to financial support for “normal” ground-mounted systems in accordance withsection 48(1) no. 3 EEG 2023 or section 37(1) no. 2(c) EEG 2023.
43 See section 38b(1) sentence 2 EEG 2023.
44 For systems with a reference value that is determined in law, this is based on section 48(1) no. 5(e) EEG 2023.

67

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

additional use. It is a good idea to exploit this potential too,
but the technology bonus should be granted in addition to
the “marsh bonus” for stilted, overhead marsh systems. Thiscan be achieved by adding the following clause to section
38b(1) sentence 3 EEG 2023: “Sentence 2 applies accordingly
if the additional agricultural use of the land (paludiculture) isregulated in accordance with section 85c(1) sentence 3.”
This area can only be extended for systems that take partin tenders: Financial support can then also come into
consideration for land with plots that were used as arable landor grassland at the time the decision to establish or amend
the development plan was made. In short, we can say that theareas of land cannot be assigned to any land category otherthan that specified in section 37(1) no. 2 EEG 2023 and arelocated in a constrained area.47 It should be noted that thedefinition of a constrained area in section 3 no. 7 EEG 2023
has been expanded to include the areas of land referencedin (b). However, this expansion only applies where the state
government has passed a legal ordinance for tenders on landin such areas. This has so far only happened in Bavaria, BadenWürttemberg, Hesse, Lower Saxony, North Rhine-Westphalia,
Saxony, Saxony-Anhalt, Saarland and Rhineland-Palatinate
on the basis of EEG 2021 — and therefore with the current
definition of a constrained area.
In principle, there are no exclusions or superior/subordinate
relationships between the regulations regarding rooftop
systems, systems on structural facilities, “conventional”
ground-mounted systems and special solar PV systems. Thereis no basis for this in the wording of the regulation, and it is
not necessary in view of the purpose of the funding. In fact,
the relevant entitlement to claim payment is linked solely to thedifferent land-related requirements and the tenderer or system
operator can decide which funding category to claim if therequirements for several funding conditions have been met.48

Only in the case of land in constrained areas in accordancewith section 37(1) no. 2(h) or (i) EEG 2023 should the land not
be one of the types specified in (a) to (g) or (j) of section 37(1)
no. 2 EEG 2023.
Innovation tenders49
Only system combinations as defined in the German Innovation
Tender Ordinance (Innovationsausschreibungsverordnung,
InnAusV) are entitled to participate in innovation tenders.
In other words, the agrivoltaic systems must be linked toa storage system or another renewable energy system andfeed in the electricity via a common grid connection point.50
Tenderers who succeed in the tender will receive the market
premium from the grid operator for the electricity fed in as
per section 19(1) no. 1 EEG 2023.51 The fixed market premiumhas been abolished, as have the special regulations for special
solar PV systems, as these were transferred to the first-segment
tenders as of January 1, 2023 in accordance with EEG 2023.52
It is questionable whether the technology bonus can also be
claimed when a stilted, overhead agrivoltaic system is part ofthe system combination. The same applies to the marsh bonus
in the case of marsh PV.
In section 3(3) InnAusV (old version), reference was madeto section 38b EEG 2021 and the application of this was
mandated accordingly. This was necessary as the reference
value was used as the basis in section 38b EEG 2021 andsection 38b EEG 2021 should be read with reference to this
fixed market premium. The reference has been removed in the
Easter amendment. This is justified on the grounds that theabolition is an amendment that follows on from the abolitionof the fixed market premium, so that “the cited standards
are to be applied directly.”53 The starting point for this direct
application is section 3(1) InnAusV. As such, there are strong
arguments that section 38b(1) sentence 2 or 3 EEG 2023 is

45 See section 85c(2) EEG 2023; definition dated October 1, 2021 — file no.: 8175-07-00-21/1, available at: https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Energie/Unternehmen_Institutionen/Ausschreibungen/Innovations/GezeichneteFestlegungOktober2021.
pdf;jsessionid=2CCC48CFBAEEAB49D559C0D002E2107D?__blob=publicationFile&v=3
46 Available at: https://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Sachgebiete/Energie/Unternehmen_Institutionen/Ausschreibungen/Solar1/
BesondereSolaranlagen/Festlegung.pdf?_blob=publicationFile&v=2
47 See section 37(1) no. 2(h) and (i) EEG 2023.
48 This is also the position of Clearingstelle EEG|KWKG on the regulations regarding conversion areas (section 37(1) no. 3(b) EEG 2017) and other structural facilities(section 37(1) no. 2 EEG 2017) in the arbitration award dated January 11, 2019 — file no. 2018/39, available at https://www.clearingstelle-eeg-kwkg.de/sites/
default/files/Schiedsspruch_2018_39.pdf).
49 This document does not discuss tenders for innovative concepts with hydrogen-based storage of electricity in accordance with section 39o EEG 2023 or for systems
for generating electricity from green hydrogen in accordance with section 39p EEG 2023. Agrivoltaic systems could play a role in this context but the relevant
ordinances have not yet been passed, so no specific statements can currently be made on the subject.
50 See section 2(1) InnAusV.
51 See section 8(1) InnAusV.
52 For more information on the original regulations, see Vollprecht/Kather, IR 2021, 266 (268).
51 See explanatory memorandum, Bundestag document no. 20/1630, p. 261.

68

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

to be applied in the case of tenders from January 1, 2023
to electricity from a stilted, overhead agrivoltaic system or
marsh PV system that is part of the system combination. If
a storage system is part of this type of system combination,
this ultimately also applies to electricity from the storage
system that is fed into the grid. This is because — in brief — it
can be taken from section 8(2) InnAusV that electricity takenout of the storage system receives financial support just as
the electricity fed into the storage system would have done
if it had been fed immediately into the grid. In order to avoid
legal uncertainty, it would nevertheless be useful to bringappropriate clarification to InnAusV and add sentence 2
below to section 8(1) InnAusV: “The entitlement can increase
pursuant to section 38b(1) sentences 2 and 3 of the Renewable
Energy Sources Act (Erneuerbare-Energien-Gesetz, EEG).”

7.4.4

Local government involvement inground-mounted systems

With regard to acceptance, section 6 EEG 2023 is of interest:
This regulation states that operators of ground-mounted solar
PV systems can grant affected municipalities allowances of up
to 0.2 cents per kWh fed into the grid.49 For systems in receipt
of financial support, the allowances are reimbursed by thegrid operator. For other systems (“PPA systems”), the system
operator must bear this cost themselves.

53 For a similar regulation for wind farms, see Baur/Lehnert/Vollprecht, EnWZ 2021, 341 et seq. The Bundesverband Neue Energiewirtschaft e. V. has developed
a template contract for community participation, which is available at https://sonne-sammeln.de/mustervertrag/.

69

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

8

Promoting agrivoltaics

Society is faced with challenges of previously unknown
magnitude due to the climate crisis, water scarcity andthe steadily increasing demand for energy and foodstuffs.
Whether and how humanity will overcome these global
challenges will be decided in the coming years. To maintainquality of life in industrialized countries and improve it in the
countries of the Global South, we need to find ways to achieve
seemingly conflicting goals: maintaining prosperity, facilitating
development and a livable future, and simultaneously reducing
the consumption of natural resources and the emission ofclimate-damaging substances. Agrivoltaics can make a relevant
contribution to all this.
This guideline describes the current state of agrivoltaic
technology, its potential and its various areas of application.
Aside from enabling more efficient land use, agrivoltaics canhelp increase climate resilience, reduce water consumption
in agriculture, generate stable additional sources of income
for farms and make many farms more resilient against crop
losses. Involving local citizens at an early stage is a key successfactor in the specific implementation of agrivoltaics. Witha levelized cost of electricity between six and ten euro cents perkWh, agrivoltaics is already competitive with other renewableenergy sources. The most important amendments to thelegal framework in Germany have been made in recent years,
enabling agrivoltaics to be implemented in an economical
way. In this process, the potential of other, similar PV concepts
with dual land use has been recognized and the relevant
political framework has been established, including PV systems
on marshy soil with subsequent rewetting, PV systems toincrease species diversity and agrivoltaic systems with extensive
cultivation. While this development is very welcome in thecontext of climate and species protection, adequate distinction
between the definitions of these PV concepts seems to be ofcentral importance to a sustainable market launch, so thattransparency and ultimately social acceptance of agrivoltaics

70

is achieved. The following areas of action therefore appear tobe particularly relevant in the context of the upcoming market
launch:A clear definition with measurable criteria for the different
PV concepts with dual land use, which are not intended
primarily for intensive agricultural use of the land but for
an increase in species diversity or the provision of additional
ecosystem services.
Compensation for the electricity from agrivoltaic systems
in accordance with EEG at different rates that takesufficient account of the additional costs and synergies forthe different interspace and stilted, overhead agrivoltaic
applications.
Scientific support for the market launch in order to establish
the necessary data base to evaluate the different system
types and application areas and to counteract undesirable
developments effectively and in good time.
Horticultural applications appear especially well suited forlaunching agrivoltaics on the market. Reasons for this include
the frequent close physical proximity of the growing area to the
farmyard, the high synergy potential of the cultivated crops, thelower cost of supports, and the comparatively simple process of
integrating them into the farming methods used for permanent
crops. In addition, approval processes can be implemented
in a simplified way through construction law privilege foragrivoltaic systems close to farms with a spatial and functional
relationship in accordance with section 35(1) no. 2 BauGB.
Typically, this is primarily the case for agrivoltaics in horticulture.
A general increase in agricultural value creation could
be another benefit in horticulture. This is because manyhorticultural applications are highly productive: Accounting for
only about 1.3 percent of farmland, horticulture contributes
more than 10 percent of the value created in agriculture[35].

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Creating incentives for agricultural operations to become more
active in this sector by funding agrivoltaics in horticulture could
therefore serve as leverage for the entire agricultural production
sector in Germany, even with a small proportion of land being
used for agrivoltaics. This applies in particular to fruit and berry
production.
In discussions about agrivoltaics, the argument is often madethat the potential of roof surfaces in Germany should be better
utilized first. There is no doubt that roof systems will continue
to be instrumental in PV expansion going forward, and not
only because of their local proximity and land use neutrality.
Nevertheless, there are good reasons for deploying agrivoltaics
as a supplement to the existing renewable power generation
technologies. For one thing, agrivoltaics — especially in the caseof larger systems — can be implemented more cost effectively
on average than roof systems due to economies of scale, whichhelps keep renewable power affordable. In addition, the PV
modules can, in the best case scenario, offer added benefits
for crop growth while roof systems are “just” land-use-neutral.
Furthermore, the momentum of the climate crisis demands thesimultaneous activation of all reasonable options.
Admittedly, a slight decrease in crop yields has been observed
for the bulk of the systems studied to date. However, theharvest results for the research system in Heggelbach in 2018indicated that agrivoltaics, even at this early stage of thetechnological journey, could provide a possible answer tothe various challenges faced by farmers. One of them is theincreasing periods of drought in Germany. The fact that the
average temperature, extreme weather events and, in thecase of Central Europe, solar radiation will increase due tothe climate crisis suggests that a possible protective function
provided by PV modules for crops will grow in importance going
forward.
Some future fields of research for agrivoltaics include analysesof the potential in relation to different crops, construction
types, PV module tracking and validation of models for yield
forecasting. Combinations with energy storage systems,

organic PV film and solar water treatment and distribution, as
well as the use of electric farming machinery and intelligent
and automated field cultivation, are also promising researchareas in some cases. One future vision is “swarm farming”,
using smaller, automated, solar electrified agricultural
machines, which are operating under the agrivoltaic system
and generating the required energy directly in the field. This
could result in a significant reduction in clearance heightrequirements. The mounting system and power generation ofan agrivoltaic system offer conditions that are conducive tothe integration of such smart farming elements. Automatedfield cultivation is currently being integrated into the mounting
system of an agrivoltaic system at Fraunhofer ISE for testing on
a 1.2 x 3 meter area of land.
Over the long term, PV will become the cornerstone of energy
supply, alongside wind power. The climate crisis and increasingwater scarcity require new approaches in agriculture, partly tomake farms more economically and ecologically resilient. To
mitigate land use competition, agrivoltaic technology offers
a way to expand PV capacity while conserving fertile soil asa resource for food production. This dual use of the areas
considerably increases land use efficiency. Soils exposed toincreasing and more frequent severe weather events such asheat, heavy rain, or drought can be protected at the sametime. Agrivoltaics can also provide more climate-friendly energy
to cover the energy consumption of farms.
The specific challenges and funding requirements foragrivoltaic systems can only be identified as part of a crosssectoral exchange. Therefore, an important, central step is toestablish a working dialog between the agricultural and energy
sectors. Only then can a framework be created that gives due
consideration to the needs of the agricultural sector, on the
one hand, and to the technical and economic opportunitiesof the PV sector, on the other. Only then can agrivoltaics be
successfully promoted with targeted and systematic funding.
Only then can the opportunities offered by agrivoltaics for
agriculture and the energy transition be fully seized.

71Agrivoltaics: Opportunities for Agriculture and the Energy Transition

9

9.1

[1]

[2]

[3]
[4]

[5]

[6]

[7]

[8]

72

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D. Ketzer: Land Use Conflicts between Agriculture andEnergy Production. Systems Approaches to Allocate
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Dissertation,. 2020
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erneuerbare-energien.de/EE/Redaktion/DE/Downloads/
bmwi_de/zsv-boschundpartner-vorbereitung-begleitungeeg.pdf?__blob=publicationFile&v=7[9] Bundesverband Solarwirtschaft e. V.: Entwicklung desdeutschen PV-Marktes. Auswertung und grafische
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zeitreihen.html?nn=344886#buehneTop, accessed on:
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[11] M. Ionita, V. Nagavciuc, R. Kumar, and O. Rakovec:
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precipitation deficit in central Europe. npj Climate andAtmospheric Science 3 (2020) 1[12] A. Weselek, A. Ehmann, S. Zikeli, I. Lewandowski,
S. Schindele, and P. Högy: Agrophotovoltaic systems:
applications, challenges, and opportunities. A review.
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Verwendung nachwachsender Rohstoffe in Deutschland.
As of: March 2019, 2019[14] Fraunhofer Center for International Management andKnowledge Economy IMW: Nachhaltige Kombination
von bifacialen Solarmodulen, Windenergie und Biomasse
bei gleichzeitiger landwirtschaftlicher Flächennutzungund Steigerung der Artenvielfalt, year not specified(final report) https://www.openagrar.de/servlets/
MCRFileNodeServlet/openagrar_derivate_00043193/
BMWi_03EI5209A-D_Schlussbericht-TIB-20211129.pdf[15] Next2Sun GmbH: References. https://www.next2sun.de/referenzen/[16] Feasibility and Economic Viability of Horticulture
Photovoltaics in Paras, Maharashtra, India, M. Trommsdorff,
S. Schindele, M. Vorast, N. Durga, S. M. Patwardhan,
K. Baltins, A. Söthe-Garnier, and G. Grifi, 2019[17] K. Schneider: Agrophotovoltaik: hohe Ernteerträge imHitzesommer. Freiburg 2019[18] K. Schneider: Agrophotovoltaik goes global: von Chile bis
Vietnam. Freiburg 2018[19] G. P. Brasseur, D. Jacob, and S. Schuck-Zöller:
Klimawandel in Deutschland. Berlin, Heidelberg: Springer
Berlin Heidelberg 2017

Agrivoltaics: Opportunities for Agriculture and the Energy Transition[20] J. Ballester, X. Rodó, and F. Giorgi: Future changes inCentral Europe heat waves expected to mostly follow
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and J. E. Macknick: Agrivoltaics provide mutual benefits
across the food–energy–water nexus in drylands. Nature
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and radiation use efficiency of lettuces grown in thepartial shade of photovoltaic panels. European Journalof Agronomy 44 (2013), p. 54 – 66
[23] S. K. Abeysinghe, D. H. Greer, and S. Y. Rogiers: The
effect of light intensity and temperature on berry
growth and sugar accumulation in Vitis vinifera “Shiraz”
under vineyard conditions. VITIS - Journal of Grapevine
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Potential to 2025, International Renewable Energy
Agency, 2016[26] Solaranlage Ratgeber: Anschaffungskosten fürPhotovoltaik-Anlagen, year not specified https://www.
solaranlage-ratgeber.de/photovoltaik/photovoltaikwirtschaftlichkeit/photovoltaik-anschaffungskosten,
accessed on: August 7, 2020[27] E.ON Energie Deutschland GmbH: Solaranlage Kosten:
Was kostet Photovoltaik 2020?, year not specified https://www.eon.de/de/pk/solar/photovoltaik-kosten.html,
accessed on: August 7, 2020[28] K. Grave, M. Hazart, S. Boeve, F. von Blücher,
C. Bourgault, N. Bader, B. Breitschopf, N. Friedrichsen,
M. Arens, A. Aydemir, M. Pudlik, V. Duscha, andJ.Ordonez: Stromkosten der energieintensiven Industrie.
Ein internationaler Vergleich. Zusammenfassung derErgebnisse, 2015[29] A. Tietz: Der landwirtschaftliche Bodenmarkt —Entwicklung, Ursachen, Problemfelder.
Wertermittlungsforum 36(2) (2018), p. 54 – 58

[30] B. Valle, T. Simonneau, F. Sourd, P. Pechier, P. Hamard,
T. Frisson, M. Ryckewaert, and A. Christophe: Increasing
the total productivity of a land by combining mobile
photovoltaic panels and food crops. Applied Energy 206(2017), p. 1495 –1507[31] Y. Elamri, B. Cheviron, A. Mange, C. Dejean, F. Liron,and G. Belaud: Rain concentration and sheltering effectof solar panels on cultivated plots. Hydrology and Earth
System Sciences 22 (2018) 2, p. 1285 – 1298
[32] C. Rösch: Agrophotovoltaik — die Energiewende in der
Landwirtschaft. GAIA - Ecological Perspectives for Scienceand Society 25 (2016) 4, p. 242 – 246[33] Soziales Nachhaltigkeitsbarometer der Energiewende
2019. Kernaussagen und Zusammenfassung derwesentlichen Ergebnisse, I. Wolf, Potsdam 2020[34] Soziales Nachhaltigkeitsbarometer der Energieund Verkehrswende 2021. Kernaussagen undZusammenfassung der wesentlichen Ergebnisse, I. Wolf,
A.-K. F. Fischer, and J.-H. Huttarsch, Potsdam 2021
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Future — Forschung für die Herausforderungen derEnergiewende (2019)[36] D. Ketzer, N. Weinberger, C. Rösch, and S. B. Seitz: Landuse conflicts between biomass and power production —Citizens’ participation in the technology developmentof agrophotovoltaics. Journal of Responsible Innovation(2020) 7 (2), p. 193 – 216[37] D. Ketzer, P. Schlyter, N. Weinberger, and C. Rösch:Driving and restraining forces for the implementationof the Agrophotovoltaics system technology A system
dynamics analysis. Journal of environmental management
270 (2020), p. 110864[38] BMEL German Federal Ministry for Food andAgriculture: Der Gartenbau in Deutschland Auswertungdes Gartenbaumoduls der Agrarstukturerhebung
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Downloads/DE/Broschueren/Gartenbauerhebung.
pdf?__blob=publicationFile&v=773

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

9.2

List of figures

Fig. 1Agrivoltaic research site at Lake Constance© Fraunhofer ISE4
Illustration of an agrivoltaic system
5© Fraunhofer ISEPartners in the APV-RESOLA project
5
How agrivoltaics has developed since 1981
© Fraunhofer ISE6
Land used for ground-mounted PV systems inGermany since 2004; total land used and yearly
expansion © Federal Ministry for Economic Affairs
and Climate Action BMWK [8]7
Applications for integrated photovoltaics© Fraunhofer ISE8
Typical ground-mounted PV system© Fraunhofer ISE8
Precipitation and global solar radiation in Germany
since 1991. Data: Deutscher Wetterdienst© Fraunhofer ISE9Classification of agrivoltaic systems© Fraunhofer ISE
10Illustration of the categories and forms of land use
as set out in DIN SPEC 91434 © Fraunhofer ISE
12
L and use in Germany © Fachagentur
Nachwachsende Rohstoffe e. V. (2023) [13]
12C
 ross-section view of the agrivoltaic system in
Weihenstephan © 2020 B. Ehrmaier, M. Beck,
14
U. Bodmer
Illustration of the agrivoltaic reference system
15
in Heggelbach © AGRISOLAR Europe GmbHT he agrivoltaic system at Hofgemeinschaft
Heggelbach enabled the farm to cover almost allof its energy demand in summer 2017 using thepower generated with the system © BayWa r.e.
15T he dual use of land for agrivoltaics and potato
growing increased land-use efficiency on the
Heggelbach test site to 186 percent© Fraunhofer ISE16A grivoltaic system at the Nachtwey organic fruit
farm (2021, 2023) © Fraunhofer ISE17
A grivoltaic system in Blankenhornsberg, 2023
© Jona Pillatzke, WBI19
Agrivoltaic system in Geisenheim© HS Geisenheim
19M odule row with bifacial PV modules on theagrivoltaic system in Heggelbach © Fraunhofer ISE 20V ertical agrivoltaic system in Aasen,
Donaueschingen © Solverde Bürgerkraftwerke
21
Agrivoltaic system in Kressbronn (2022)© Fraunhofer ISE24

Fig. 2
Fig. 3Fig. 4
Fig. 5

Fig. 6
Fig. 7
Fig. 8Fig. 9Fig. 10
Fig. 11
Fig. 12Fig. 13
Fig. 14

Fig. 15

Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20
Fig. 2174

Fig. 22 V ertical agrivoltaic system in Merzig-Wellingen, 2023
© University of Hohenheim
25
Fig. 23 P ilot PV systems in Curacaví and Lampa where theFraunhofer Chile Research Institute is investigating
which crops benefit from slightly less solar radiation© Fraunhofer Chile27
Fig. 24 Study with various types of lettuce at the agrivoltaics
research site run by the University of Montpellier inFrance © INRAE / Christian Dupraz
28
Fig. 25 PV greenhouse © Fraunhofer ISE29
Fig. 26 Crops from the research site in Heggelbach (celery,potatoes, wheat and clover grass) © University of
Hohenheim/Andrea Bauerle
30
Fig. 27 F ield plan for the 2017 research site, showing
monitoring stations. Areas where samples weretaken are shown as boxes, and the positions of
the microclimate stations are shown as circles© BayWa, modified by Axel Weselek/Universityof Hohenheim
31
Fig. 28 C rop yield differences under PV modules compared
to reference plots, 2017 (blue) and 2018 (red) in
Heggelbach (excluding land lost due to supports)
Data: University of Hohenheim, © Fraunhofer ISE 32
Fig. 29 Impact protection for the supports of the system
in Heggelbach to protect against damage fromfarming machinery © AGROSOLAR Europe GmbH 32
Fig. 30 Illustration of an agrivoltaic apple orchard© Fraunhofer ISE33
Fig. 31 A grivoltaic system with solar tracking PV modules
in France © Sun’Agri
34
Fig. 32 W eather protection for raspberries provided byagrivoltaics. 300 kWp test system by BayWa r.e.
34
in the Netherlands © BayWa r.e.
Fig. 33 D emo project in berry cultivation shows high value
creation in agriculture © BayWa r.e.
35Fig. 34 Harvesting wheat with a combine harvester© Fraunhofer ISE35
Fig. 35 G
 raph of the rate of photosynthesis against
intensity of sunlight for sun loving and shadetolerant crops[24] © ASPS, modified by
Fraunhofer ISE36
Fig. 36 Vertically deployed, bifacial PV modules used within
the agrivoltaic system in Eppelborn-Dirmingen,
Saarland, with 2 MWp of capacity, built by
36
Next2Sun © Next2Sun GmbHFig. 37 T homas Schmid and Florian Reyer from
Hofgemeinschaft Heggelbach © AMA Film GmbH 37
Fig. 38 E stimated capital expenditure (CAPEX) for groundmounted PV and agrivoltaic systems© Fraunhofer ISE39

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

Fig. 39 A
 comparison of estimated levelized costs ofelectricity by capital expenditure (CAPEX) andoperating expenses (OPEX) of ground-mounted
PV systems and agrivoltaic systems
40© Fraunhofer ISEFig. 40 Estimated levelized cost of electricity (LCOE) for
ground-mounted PV and agrivoltaic systems© Fraunhofer ISE41
Fig. 41 Stakeholder groups and contractual model© Fraunhofer ISE43
Fig. 42 Stilted, overhead system enabling cultivation
with a potato harvester © Hofgemeinschaft
Heggelbach44
Fig. 43 PV modules with spatially segmented solar
cells and protective function in the Netherlands© BayWa r.e.
44Fig. 44 Bifacial, vertically installed PV modules by
Next2Sun, Eppelborn-Dirmingen45© Next2Sun GmbHFig. 45 PV modules above a polytunnel © BayWa r.e.
45
Fig. 46 Special thin-film tubular modules fromTubeSolar © TubeSolar AG
45
Fig. 47 Semi-shade from tubular PV modules
installed between tension cables by TubeSolar© sbp sonne GmbH45
Fig. 48 Stilted, overhead systems with narrow PV modules
45
in Italy © REM TecFig. 49 Stilted, overhead system with continuous rows of46
modules © Sun’Agri
Fig. 50 Single-axis tracker system on a demonstration
system in France © Sun’Agri
47
Fig. 51 Spinnanker anchor with anchor plate and threadedrods provides the foundation for the installation48
system © Spinnanker GmbHFig. 52 Illustration of different system types oriented
east‑west, south and south-east © Fraunhofer ISE 48
Fig. 53 The shaded strips underneath the PV
modules move with the sun’s position© University of Hohenheim
49
Fig. 54 Transparent PV modules casting a shadow overvines © Hochschule Geisenheim University
49
Fig. 55 Concept for a rain collection facility with storagetank © Fraunhofer ISE50
Fig. 56 Agrivoltaic system in Heggelbach with a capacityof 194 kWp covering approximately a third ofa hectare © Fraunhofer ISE50
Fig. 57 Eppelborn-Dirmingen solar farm with 2 MWp
with vertical solar fences by Next2Sun© Next2Sun GmbH50

Fig. 58 Working in an agrivoltaic system under the solar
PV modules © Fabian Karthaus
52
Fig. 59 Construction roads to avoid soil compaction© BayWa r.e.
53
Fig. 60 Maintenance work on the agrivoltaic system
in Heggelbach © Fraunhofer ISE53
Fig. 61 Citizens’ information workshop in the APV-RESOLA
project © ITAS
56
Fig. 62 Model of the agrivoltaic system in Heggelbach
for information workshops © Fraunhofer ISE56
Fig. 63 Multi-stage transdisciplinary agrivoltaic research
approach © ITAS
57
Fig. 64 Where agrivoltaic systems produce strips thatcannot be farmed, these could be used toincrease biodiversity on the agricultural land
© Fraunhofer ISE59
Fig. 65 Example process for a building application© Fraunhofer ISE
61

75

Agrivoltaics: Opportunities for Agriculture and the Energy Transition

9.3

List of tables

Tab. 01 Overview of categories and forms of land use as
set out in DIN SPEC 91434
Tab. 02 O
 verview of agrivoltaic research sites in Germany
to date
Tab. 03 D amage to cabbage crops © 2020 B. Ehrmaier,
M. Beck, U. Bodmer
Tab. 04 O
 verview of specified operational systems andcertain other operational systems in Germany
Tab. 05 O
 verview of some research projects in Germany
Tab. 06 C onfigurations of different agrivoltaic businessmodels (based on Schindele et al. 2019[5])
Tab. 07 Overview of approval steps for agrivoltaics

9.5

Links to further information

Agrivoltaics website of Fraunhofer ISE: https://www.agri-pv.org
11
13
14
20
23
43
52

Short film about the agrivoltaic research site in Heggelbach:https://www.youtube.com/watch?v=BlXPf-e1a0U
Guidelines for ground-mounted solar power systems
from the Ministry of the Environment, Climate Protection
and the Energy Sector Baden-Württemberg:
https://um.baden-wuerttemberg.de/de/service/publikation/did/handlungsleitfaden-freiflaechensolaranlagen/R&D for agrivoltaics at Fraunhofer ISE: https://ise.link/agri-pv
APV Obstbau project website: https://www.ise.fraunhofer.de/de/forschungsprojekte/apv-obstbau.html

9.4

Acronyms

Agri-PV		Agrivoltaics
APV-RESOLA	Agrophotovoltaik-Ressourceneffiziente
Landnutzung, Resource-efficient land use withagrivoltaics
BauGB 		 Baugesetzbuch, German Building CodeBMBF		German Federal Ministry of Education andResearch
CAPEX		 Capital Expenditure
CIS		 Copper Indium Selenide
CdTE		 Cadmium Telluride
CPV		 Concentrating Photovoltaics
EE		 Renewable energy resources
EEG		Erneuerbare-Energien-Gesetz, Renewable
Energy Sources Act
GW		 Gigawatt
GWh		 Gigawatt-hour
kW		 Kilowatt
kWh		 Kilowatt-hour
LCOE		Levelized Cost of Electricity
MW		 Megawatt
MWh		 Megawatt-hour
OPEX		 Operational Expenditure
OPV		 Organic Photovoltaics
PPA		 Power Purchase Agreements
PV-FFA		 Ground-mounted photovoltaic systems
REAP		 Rural Energy Advancement Programs
STC 		 Standard Test Conditions
TWh		 Terawatt-hour
W		 Watt
Wh		 Watt-houra-Si		 Amorphous Siliconµ-Si		 Microcrystalline Silicon
ZALF		Leibniz Centre for AgriculturalLandscape Research, Leibniz-Zentrum fürAgrarlandschaftsforschung76

Agrivoltaics sector directory of the LandSchafftEnergie
consultancy network: https://www.landschafftenergie.bayern/
beratung/branchenverzeichnis/
DIN SPEC 91434:2021-05, “Agri-Photovoltaik-Anlagen —Anforderungen an die landwirtschaftliche Hauptnutzung”[“Agri-photovoltaic systems — Requirements for primary
agricultural use”]: https://www.beuth.de/de/technische-regel/
din-spec-91434/337886742
Status report on agrivoltaics from the Technology andSupport Centre, Straubing: https://www.tfz.bayern.de/service/presse/268709/index.php

Precipitation and global radiation

77

Funded byGerman Federal
Ministry of Education
and Research

German Federal
Ministry for Foodand Agriculture

Contact
Dr. Max Trommsdorff
Phone +49 761 4588-2456
max.trommsdorff@ise.fraunhofer.de
Dr. Harry Wirth
Director, Division Power Solutions
Fraunhofer Institute for
Solar Energy Systems ISE
Heidenhofstrasse 2

www.ise.fraunhofer.de
www.agri-pv.org
Head of InstituteProf. Hans-Martin Henning
Prof. Andreas Bett

PDF version of theagrivoltaics guidelinei

Cover image: © Lucía Garstka, HS Geisenheim

79110 Freiburg, Germany