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The decarboniza�on solu�ondeveloped in Japan

Solar Sharing(Agrivoltaics)

Learn, discuss and share.
Spring 2023

Business & Industries
Climate Ac�on Group

ビジネス・BusClWhat is solar sharing?
▶ Also known as agrivoltaic farming,

solar sharing is a system of placing elevated photovoltaic (PV) panels over agricultural land, making
it possible to simultaneously produce energy andcrops by “sharing” the light of the sun.

米・麦その他

９％

12％

Akira Nagashima focused on light satura�on in plant photosynthesis to develop the basic concept
野菜など

観賞用植物of agrivoltaics in 2003, naming it “solar sharing,” and later publishing
the patent.

35%

30%

Light satura�on generally refers to the point in plant photosynthesis where increased light intensity no longer increases photosynthesis. This means that light over this amount doesn’t contribute to果樹

growth and is simply surplus. Giving plants the sunlight they need and “sharing” the surplus light14%

with PV panels makes it possible to simultaneously produce both crops and energy, oﬀering poten�al solu�ons to a number of issues in Japan and around the world.

Data: Shading rate and crop type

Rice & other grains
OtherShading rate is the amount of shade created by the PV

12％panels, and is expressed by as follows.
the total area of panels
×100 [%]
the area of farmland where the frames are installed

Solar sharing is set up in a way to normally have about a
30% shading rate.
Diﬀerent plants have their own light requirements that
dictate the strength of light they prefer in order to grow,making it necessary to construct each facility to have ashading rate that suits the desired agricultural crop.
As shown by the chart at the right, rice and other grains,vegetables and potatoes, fruits, decora�ve plants andother crops are all currently being grown on solar sharing
farmland.

29%

Decorative

Vegetables,

30%

35%

potatoesplantsFruit
14%

Ra�os of diﬀerent crops that are grownbeneath agrivoltaic facili�es (based onnumber cases where a crop is grown)
Japan’s Ministry of Agriculture, Forestry
and Fisheries Rural Development Bureau
Detailed Survey of Agrivoltaic Farming
Facili�es(End of FY2020)

Issues facing Japan that we believesolar sharing can help solve
Figh�ng climatechangeThe Japanese government has set a goal of reducing greenhouse gas
emissions by 46% over FY2013 by FY2030, and achieving net zero
emissions by FY2050.
▶ Renewable energy reduces CO2 emissions▶ Regenera�ng abandoned or disused farmland creates carbon sinks

Improving energy
self-suﬃciency

Japan’s FY2021 self-suﬃciency rate for primary energy (including nuclear)
was 13.4%, which is very low for an industrialized country. Japan is largely
dependent upon imports of fossil fuels like oil, coal and natural gas (LNG).
▶ Distributed renewable energy improves energy self-suﬃciency▶ Agrivoltaics expand community-based solar power genera�onImproving foodself-suﬃciency

Japan’s FY2021 food self-suﬃciency rate by calorie supply basis was 38%.
With countries like Canada (233%), Australia (169%) and the US (121%) all
exceeding 100%, this puts Japan at the bo�om of the list of the world’s
major countries.**Canada, Australia, US, France, Germany, UK, Italy, Switzerland, Japan▶ Regenera�ng abandoned or disused farmland can improve food self-suﬃciency▶ Increasing income helps retain farmers and a�ract the next genera�on

Revitalizing local
communi�esJapan is experiencing ongoing centralization towards major cities, with35.4% of the popula�on living in the Greater Tokyo Area and 52.5% living
in or around Tokyo, Osaka and Nagoya. Most other areas are experiencing
depopula�on.
▶ Distributed energy can be used within the community▶ Ac�ve farming increases local food self-suﬃciency and revitalizes communi�es3This is what’s amazing about solar sharing!
1. The beneﬁts of earning income through agrivoltaic farminga) Helps stabilize farming opera�ons with addi�onal income.
b) Promotes con�nued stable farming and the regenera�on of abandoned/ disused farmland.
c) Keeps costs down by providing self-generated energy for farming equipment and facili�es.
2. The beneﬁts of providing par�al shadea) Regulates excess light to help improve the quality of agricultural products.
b) Becomes an opportunity to venture into new types of crops.
c) Provides shade in the summer when heat makes farmwork in open ﬁelds diﬃcult.
d) Reduces ambient dryness, helping conserve irriga�on water.
3. The beneﬁts of the facili�es themselvesa) Frames can be used to hang insect and bird nets, sun shades or security cameras.
b) Inhibits radia�ve cooling in winter, reduces snow accumula�on and promotes mel�ng.
4. The beneﬁts to societya) Helps local communi�es reach decarboniza�on goals by u�lizing farmland to generate solar power.
b) Combines fighting climate change with supporting the survival of farming to provide uniquebranding for local agricultural products.
c) Contributes to na�onal food security by regenera�ng abandoned/ disused farmland.
d) Provides opportuni�es to encourage new farmers and expand the so-called 6th industry* by introducing carbon-absorbing farming methods like no-�ll, and new systems that u�lize IoT.

Growing soybeans using no-�llWorking in the shade, even in hot weather
4

farming (Sosa City)

Solar Sharing FAQ
1. Are there any crops par�cularly suited to solar sharing?
Using solar sharing setups that provide up to a 35% shading rate, there should be no problem growing almost any kind of crops (see chart at the bo�om of page 2). There are plenty of examples offarms growing a truly wide variety of crops by se�ng the panel shading rate and other variables tosuit individual types of produce.
2. Does the equipment get in the way of farm work?
The height and distance between the frames are to be set up in a way that provides enough spacefor eﬃcient use of machinery and other farming equipment, so that they don’t impede work (seephoto at the bo�om of page 6 of farming being done by tractor).
3. Can solar sharing really make abandoned farmland produc�ve again?
Even land that has been abandoned because there is no one to tend to it can be returned to farmland by using the income from selling electricity produced by solar sharing. In Japan, designatedType 1 agricultural land cannot be converted to other uses, which has been a hurdle to eﬀec�veland use. This makes solar sharing even more promising as a way to revitalize farmland.
4. What are the requirements for installing solar sharing?
Because the area of farmland where the foundation of the frames is installed will be used for
non-agricultural purposes, it may be necessary to acquire a permit for temporary alterna�ve usefrom a local board of agriculture. In Japan this is con�ngent on ensuring that proper farming con�nues beneath the power facility, and actual harvest volumes of the crops must be reported to the relevant commi�ee each year. It is also necessary to reapply for the permit every three years (or every
10 if certain condi�ons are met), which requires showing that the equipment is not impeding crop
produc�on.
5. How will the PV panels be disposed of at the end of their life?
Reusable panels are collected by a specialized contractor that ensures they are reused, and all othertypes are collected by a recycling contractor that separates them into component elements like aluminum and glass to be recycled. As of November 2022, there are 31 intermediate processing companies throughout Japan that have developed technology for recycling and appropriate disposal of PV
panels, and this number is expected to increase in the future.
Since July 2022, power producers have also been required to set aside funds to cover disposal costs.
5Solar Sharing in ac�on
1. Shimin Energy Chiba K.K. (Sosa City, Chiba Prefecture)
More than 40 years ago, about 80 ha of open farmland were developed in the local area using government funding, yet much of this was later abandoned. Star�ng in December 2013, there werea number of private investments related to the environment and renewable energy in Chiba thatcreated con�nued interest in building “people’s power plants,” which led to the establishment ofShimin Energy Chiba LLC in July 2014 and the prefecture’s ﬁrst 35 kW community power plant.
Since establishing an additional company incharge of farming , the group has a�racted more
and more advocates and expanded their list ofaﬃliates and facili�es over eight years. They are
growing rapidly, and currently have a total of
400 million yen in capital and a generation capacity of 6 MW. The area is thus now known as“solar sharing village.”
As the soil here is not fer�le, they primarily farmsoybeans, azuki beans and barley using organic farming methods below the PV panels. The
soybeans are processed into products like miso
paste and coﬀee subs�tute to also tap into theSolar sharing village

6th industry.
With the help of Professor Masakazu Komatsuzaki of Ibaraki University and Professor Nobuhiro Kaneko of Fukushima University, they are also
trialing no-�ll farming, which helps improves soil
health through microorganisms. In the spirit of anon-proﬁt limited liability company, proﬁts a�er
expenses are put back into renewable energy
and other environmental ini�a�ves rather thansplit between investors.

6Working beneath the photovoltaic (PV) panels

2. Nihonmatsu Agricultural Solar K.K. (Nihonmatsu City, Fukushima Prefecture)
Nihonmatsu Agricultural Solar is an agricultural power generator that is operated by three companies: Civic Power Plant Gochikan LLC, a community power company that is working to increase
community self-sufficiency, local co-op MIYAGI COOP, and the Institute for Sustainable Energy
Policies that supports them. The 4-MW power genera�on facility stands on 6 ha of farmland that isowned and operated by Sunshine, a corpora�on qualiﬁed to own cropland.
Looking out onto Mt. Adatara, the facility produces
electricity to serve 500 households — about 2.5%of those in Nihonmatsu City — and crops such as
Shine Muscat grapes, perilla and buckwheat. It is aworking example of a new kind of land u�liza�onwhere agricultural and energy production don’t
need to compete, even in Japan where ﬂat land is
at a premium.

3. Sanuki Paddy Fields K.K. (Marugame City, Kagawa Prefecture)
As an agricultural management company, they use smart farming to raise produc�vity and makeother improvements. Of their total 3.7 ha of farmland, they have installed PV panels over about 0.6
ha of paddy ﬁelds, which generate 444 kW of electricity. They combine this with smart technologies, including innova�ons such as remote-operated automa�c water gates powered by a smart
farming management pla�orm and drones.
They also partner with research institutes anduniversities, and have gained knowledge and experience in stabilizing panels’ impact on crops andharvest volumes. The panels par�ally block direct
sunlight, mi�ga�ng the rise in water temperaturein the ﬁeld and helping reduce damage caused byheat stress.

735%30%477 万 ha

果樹耕作地

14%

435 万 ha91％

The poten�al of solar sharing
If solar sharing was installed on 10% of Japanese farmland…
Rice & other grains

We have done some calcula�ons about solar sharing and found
Other

that, if it was expanded to a furtherof the total 4.77 mil12％10% 9%

Abandoned cropland
420,000 ha
9％lion ha of farmland in Japan (and abandoned farmland makes
Vegetables,
Decorative
up 9% of total agriculturalland), the energy
output would
potatoesplantscover about 37% of na�onal electricity needs, and would be35%

30%

equivalent to that of 53 nuclear power plant unit.
Fruit

Agriculturalland
4.77 million ha
Cultivated land 91%
4.35 million ha

14%

Note: The calcula�on was performed using the following condi�ons.
1. A facility use rate for solar sharing of 15.5% based on the latest sta�s�cs available from Japan’s Agency for Natural
Resources and Energy on general solar power plant opera�ons.
2. A genera�on capacity of 50 kW per 1,000 sqm of solar sharing-equipped farmland.
3. A genera�on capacity of 1 million kW per nuclear power plant unit, based on the average of the remaining reactors.
4. A facility use rate for nuclear power plants of 70%, considering down�me for regular inspec�ons and other factors.
Further details on the calcula�on can be found through the QR code below (in Japanese).

● Our hope for solar sharing
About two thirds of Japan is mountainous, and with so li�le ﬂat land, there is great need for morecommunity-based solar power facili�es on roo�ops and land that isn’t being used eﬃciently.
Solar sharing has been devised to be�er u�lize agricultural land, and we hope to see greater adop�on of this home-grown technology across diﬀerent types of farmland, including abandoned cropland. Japan is o�en seen as a passive player when it comes to addressing climate change, so we areproud and excited to let the world know about the appeal and value of solar sharing.

CRP (Climate Reality Project) is the worldwide non-proﬁt organiza�on focusing
on climate change educa�on and advoca�ng for climate solu�ons.
Business industry group is one of the ac�ve seven groups in Japan brunch.

Here’s the QR code for the list of reference.
(only in Japanese)
Published on April 15 2023
Published by CRP Japan (Business Industry Group)
Kohei Suzuki, Yuna Kimura, Shoichi Hayashi, Masako Inagaki,
Wataru Kawamura, Yosuke Homma
Hiroki Matsubara (Energy Transi�on group)8

ビジネス・インダストリーグループ
Businesses & Industries
Climate Action Group