Key strategies towards
Decarbonization of Energy Use andSupply in Japan and Germany:
Insights from a Comparison Study on
Long-term Scenario Analyses up to
2050
Authors:
Hideaki Obane (Institute of Energy Economics, Japan)
Naomi Gericke, Lotte Nawothnig, Fiona Bunge (Wuppertal Institute for Climate,
Environment and Energy)Peter Hennicke (Hennicke.Consult)

Study for the GJETC
Wuppertal, Tokyo, March 2022

GJETC: Long-term scenario analysis

IImprint

Publisher
Wuppertal Institute for Climate, Environment andEnergyDöppersberg 1942103 Wuppertal
Germany
www.wupperinst.org
The Institute of Energy Economics, Japan
Inui Bldg. Kachidoki, 10th/11th Floor
13-1, Kachidoki 1-chome, Chuo-ku,
Tokyo 104-0054
Japanhttps://eneken.ieej.or.jp/en/
Contact
GJETC Secretariat
gjetc@wupperinst.org
Phone: +49 202 2492-143
Fax: +49 202 2492-108

This GJETC Study received financial support from the German Federal Ministry for theEnvironment, Nature Conservation and Nuclear Safety (BMU) and the Japanese Ministry of
Economy, Trade and Industry (METI). Responsibility for the contents of this publication lies
with the authors.

GJETC: Long-term scenario analysis

II

Content
1. Introduction.................................................................................................................. 1
1.1 Background............................................................................................................. 1
1.2 Rationale and objectives of the study.................................................................... 2
2. Update of assessment criteria and selection of studies .............................................. 3
3. Climate policy and energy transition targets for 2045/2050....................................... 6
3.1 Japan (2050) ........................................................................................................... 6
3.2 Germany (2045/2050) ............................................................................................ 7
4. Analysis of the Japanese scenarios .............................................................................. 9
4.1 Methods used and key assumptions.......................................................................... 9
4.1.1 Model comparison .......................................................................................... 9
4.1.2 Macro framework ......................................................................................... 10
4.1.3 Renewable energy capital cost ..................................................................... 10
4.1.4 Solar and wind energy potential ................................................................... 13
4.2 Key results ............................................................................................................ 15
4.2.1 Primary energy supply in 2050...................................................................... 15
4.2.2 Electricity generation mix in 2050 ................................................................ 16
4.2.3 Final energy demand in 2050 ........................................................................ 18
4.2.4 Average costs in the electric power sector ................................................... 19
4.2.5 Storage capacity ............................................................................................ 20
4.2.6 Main implications .......................................................................................... 21
5. Analysis of German scenarios .................................................................................... 22
5.1 Methods used and key assumptions.................................................................... 22
5.1.1 Scenario approaches, models and methods used ........................................ 22

GJETC: Long-term scenario analysis

III5.1.2 Framework conditions and key assumptions ............................................... 25
5.2 Key results ............................................................................................................ 29
5.2.1 Reducing the energy demand ....................................................................... 29
5.2.2 Transformation of the energy mix: Renewable energy and electrification.. 32
5.2.3 Hydrogen and PtX as energy source and raw material ................................. 37
5.2.4 Removing residual greenhouse gas emissions.............................................. 39
6. Japanese-German Comparison .................................................................................. 41
6.1 Improving energy efficiency ................................................................................. 41
6.2 Energy mix ............................................................................................................ 42
6.3 Key technologies to fully reduce CO2 emissions .................................................. 43
7. Shortcomings to achieving the net zero carbon target for 2050 in Japanese scenariosand enhanced or new strategies .................................................................................... 44
7.1 Gaps ...................................................................................................................... 44
7.1.1. Social acceptance for installation of nuclear and renewable energies ....... 44
7.1.2. Potential of CO2 storage ............................................................................... 45
7.1.3. Feasibility of massive installation of storage systems ................................. 46
7.2 Enhanced or new strategies to close the gap ...................................................... 46
7.2.1 Establishing a process to gain consensus from stakeholders ....................... 46
7.2.2 Consistency between local spatial planning and carbon neutrality ............. 47
7.2.3 Assessing the impact of non-power sectors for carbon neutrality .............. 47
8. Shortcomings to achieving the net zero carbon target for 2045 in German scenariosand enhanced or new strategies .................................................................................... 48
8.1 Shortcomings of technology-focused German scenarios .................................... 49
8.1.1. Energy efficiency first ................................................................................... 49
8.1.2 Socio-economic aspects ................................................................................ 50

GJETC: Long-term scenario analysisIV8.1.3 Policies for the actual implementation of the strategies ............................. 50
8.1.4 The ambiguous role of hydrogen .................................................................. 50
8.1.5 Compliance with international commitments: how to reach the 1,5°C-target51
8.2 Enhanced or new strategies to close the gaps .................................................... 52
8.2.1 Integration of circular economy (CE) strategies ........................................... 52
8.2.2 Consideration of sufficiency policies, lifestyle changes ................................ 53
8.2.3 “Just transition” and citizen participation ................................................... 53
8.2.4 Analysis of policies and policy integration, and their inclusion in the modelling................................................................................................................................ 54
9. Overall conclusions .................................................................................................... 55
9.1 Strategic technological options ............................................................................ 55
9.2 Improved scenario approaches ............................................................................ 56
9.3 Interlinkages between scenario modelling and policies ...................................... 58
9.3.1 Global necessities .......................................................................................... 58
9.3.2 National possibilities ..................................................................................... 59
9.3.3 Strengthening the supporting role of science – scenario-based stakeholder
dialogues ................................................................................................................ 59
9.3.4 International cooperation ............................................................................. 60
9.4 A bright or a frightening outlook?........................................................................ 60
Bibliography ................................................................................................................... 62

GJETC: Long-term scenario analysis

VTables
Table 1: Japan: Organizations that shared their scenario analysis up to 2050 _______________________________ 4
Table 2: Germany: Overview and selection of long-term scenarios up to 2045 _______________________________ 5
Table 3: Annual emission budgets according to sectors [Million t CO 2eq] ____________________________________ 7
Table 4: Model comparison _____________________________________________________________________________________ 9
Table 5: Macro framework in model assumptions ____________________________________________________________ 10
Table 6: Framework conditions ________________________________________________________________________________ 26
Table 7: Key assumptions: sectoral assumptions _____________________________________________________________ 28
Table 8: Energy demand reduction in German scenarios _____________________________________________________ 30
Table 9: Expansion of renewable energy ______________________________________________________________________ 34

FiguresFigure 1: Assumed capital costs in 2050 [thousand JPY/kW] ________________________________________________ 12
Figure 2: Assumed solar and wind energy potential in 2050 _________________________________________________ 14
Figure 3: Primary energy supply in 2050 [TWh] ______________________________________________________________ 15
Figure 4: Generated electricity in 2050 [TWh] ________________________________________________________________ 17
Figure 5: Comparison of installed capacity with technical potential [GW] __________________________________ 18
Figure 6: Final energy demand in 2050 [TWh] _______________________________________________________________ 19
Figure 7: Averaged costs in power sector [JPY/kWh] _________________________________________________________ 20
Figure 8: Storage capacity [GWh] in 2050 ____________________________________________________________________ 21
Figure 9: Total final energy demand in German scenarios (in TWh) ________________________________________ 31
Figure 10: Primary energy demand (in TWh) _________________________________________________________________ 31
Figure 11: Annual gross increases of wind and PV capacities (in GW)_______________________________________ 35
Figure 12: Net power generation by fuel plus power imports (w/o pumped hydro and batteries) ________ 36
Figure 13: Power demand of “new” uses of electricity (in TWh) _____________________________________________ 37
Figure 14: Hydrogen and PtX-Synfuels demand ______________________________________________________________ 38
Figure 15: Hydrogen import costs by region in 2045 (dena 2021) ___________________________________________ 39
Figure 16: Technical and natural negative emissions 2045 (in million tCO2eq) _____________________________ 40
Figure 17: Exemplary Emission Reduction path according to a German 1.5°C budget _____________________ 51

GJETC: Long-term scenario analysis

VI

1. Introduction
1.1 Background
The main outcome of the COP 26 in Glasgow (2021), to continue the efforts to keep 1.5
degrees within reach, remains a huge challenge even for all countries, which havecommitted themselves to a rapid and substantial reduction of greenhouse gas emissions
in the Paris Agreement (2015). Japan and Germany are among the countries that haveconsequently pledged to achieve greenhouse gas neutrality by 2050 and 2045,
respectively. In its latest report (March 2022), the Intergovernmental Panel on Climate
Change (IPCC) emphasized the urgency of more ambitious action to fight against ongoingclimate change that poses a dangerous threat to the well-being of humanity. The recent
floods, typhoons and other extreme weather events that occurred in Germany and Japan
indicate that the current climate change trends will cause immense economic damages
to national economies also in temperate climate zones. Geopolitical consequences offossil fuel dependency emerging from the Russian aggression against Ukraine add
another urgent objective for the phase-out of fossil fuels, in addition to climate change
mitigation. Against this background, climate protection and achieving climate neutrality
as quickly as possible are highest priority challenges to human kind, and they standunder extreme time pressure.
On the one hand, as leading industrialized countries, both Germany and Japan, are facinga particular responsibility and challenge to reduce greenhouse gas emissions. On theother hand, both countries can provide advanced economic, technological and societal
capacities and innovations to meet these challenges. Thus, they can benefit from theeconomic and risk-minimizing opportunities that the transformation to net zero implies.
The recent changes of governments in both countries have had remarkableconsequences for Germany and Japan's climate mitigation policies. While maintaining
the energy policy objectives of energy security, economic efficiency and environmental
sustainability, the new governments increased their ambition level and, for example,

GJETC: Long-term scenario analysis

1raised the targets for CO2 reduction, for expanding renewable energies and for fostering
energy efficiency significantly, albeit the approaches partly differ.
In both countries, scenario studies are important instruments to provide scientifically
based policy advice on complex matters such as the energy transition and to support the
governments in finding technically feasible as well as economically and socially viable
pathways to climate neutrality. However, methods, model assumptions, choice oftechnologies, policy priorities and the degree of policy integration differ between recent
scenarios studies in the two countries. For example, there are different assumptions
whether to rely on energy technology options only, or to include resource efficiency andCircular Economy (CE) strategies, as well as behaviour and lifestyle changes. Thus,
different approaches and pathways to net zero are possible.

1.2 Rationale and objectives of the study
In 2017, the GJETC had conducted a first study on the “Energy transition as a central
building block of a future industrial policy”. In a comprehensive meta-analysis of scenario
studies, a German-Japanese study team had examined a wide range of strategic options
for the energy transition as well as the associated strengths and weaknesses of theenergy transition strategies of both countries. In 2021, the GJETC decided on this followup study and to update the findings, albeit on a much smaller scale. The study objective
was to identify current climate neutrality scenarios for Germany and Japan and tocompare them based on two guiding questions: (1) Which strategic technological options
are available to reach net zero emissions?, and (2) Which lessons that might betransferable can be learned from the decarbonization strategies analyzed?
The first step consisted in identifying the range of already existing research-based, longterm scenarios, including those that go beyond current official national targets.
Assessment criteria for the selection of relevant studies and for the comparison of the
scenarios were established. In the next step, 5 Japanese and 4 German scenario studies
were selected and analyzed, comparing assumptions and results. The scenarios cover a

GJETC: Long-term scenario analysis

2range of long-term strategic options for both Germany and Japan. Moreover, gaps in theexisting scenarios were also identified. Finally, conclusions were drawn, including
potential strategies to address the shortcomings.

2. Update of assessment criteria and selection of studies
Authors: Institute of Energy Economics, Japan and Wuppertal Institute for Climate,
Environment and Energy

Based on a literature screening, a range of relevant scenario studies for Japan andGermany was identified. These studies describe the medium to long-term effects of atransition towards climate neutrality and the associated economic implications.
Following the decision of the Japanese government to reach carbon neutrality by 2050
(October 2020), only scenarios considering carbon neutrality were included. Considering
Germany’s more ambitious target to reach climate neutrality as early as 2045, a numberof scenario studies had already been published in autumn 2021. Accordingly, for the
analysis in this report, the selection of scenarios for Germany was based on the following
criteria:▪

recent publishing date, target year of climate neutrality 2045/2050▪

quantitative details for energy demand and supply side available for at least
2030▪

including aspects of economic feasibility▪

representing a broad range of assumptions and approaches

Applying these criteria, the scenarios shown in table 2 were selected from a morecomprehensive list of relevant scenario studies.
For the Japanese side, there were chosen consultants and an institute (table 1.) thatshared their own scenario analysis with the Strategic Policy Committee, in order todiscuss the direction of Japan’s energy policy, aside from the governmental strategies.

GJETC: Long-term scenario analysis

3Against this background, this study focuses on scenarios conducted by the following
organizations:

Table 1: Japan: Organizations that shared their scenario analysis up to 2050

Organization

Publication

Title

1. The Research Instituteof Innovative Technology
for the Earth (RITE)

2021

Scenario analysis aboutcarbon neutrality in 2050
(Interim report)

Founded by the GOJ to promote
innovative environmental
technologies worldwide.

Organization characteristics

2. The National Institutefor Environmental
Studies (NIES)

2021

Analysis about scenarios
toward decarbonization
by 2050

A central institute forenvironmental research since 1970.

3. Renewable Energy
Institute (REI)

2021

Energy mix supporting
decarbonization in 2050
in JapanNon-profit institute, founded by acompany-owner to promoterenewable energy.

4. Deloitte Tohmatsu
Consulting

2021

Scenario analysis forcarbon neutrality society

One of the Big Four accounting
firms.

5. The Institute of Energy
Economics, Japan (IEEJ)

2021

Model analysis forcarbon neutrality in 2050

Founded by the GOJ of theresearch institute on energy andenvironmental policies.

For the German side, we attempted to map the most recent scenarios, focusing on thetarget year 2045 and highlighting the technical and economic feasibility, while alsopresenting a certain bandwidth. Hence, (innovative) approaches also played a role, suchas considering the effects of a circular economy and behavioral changes. Against thisbackground, the following scenarios were selected. This includes the UBA (2019) study,
although it focuses on 2050, since particularly the GreenSupreme scenario we chosefrom it addresses integration aspects of climate and resource strategies that appeared to
be ground-breaking and are not covered by the other studies.

GJETC: Long-term scenario analysis

4Table 2: Germany: Overview and selection of long-term scenarios up to 2045
Organization

Publication
2021

Title
Climate Neutral Germany 2045 How Germany can achieve its
climate targets before 2050.
(Prognos et al. 2021)

The think tank searches forcompromise solutions that can gain
majority support in the
restructuring of the electricity
sector within the energy transition.
Important player in the field ofenergy policy consultancy.

2. German Energy
Agency (Dena)

2021

dena lead study – The dawn ofclimate neutrality.
(EWI 2021)

3. Federation ofGerman industries
(BDI)

2021

Climate Paths 2.0 – A programfor Climate and Germany´s
Future Development.
(BDI and BCG 2021)

A federally owned German
company that provides services toshape and implement the German
government's energy and climate
policy goals on energy transitionand climate protection.
Leading association of German
industry and industry-related
service providers, speaking for 40
industry associations and morethan 100,000 companies.

4. German Federal
Environment Agency(UBA, GreenSupreme
2050)

2019

Transformation process to agreenhouse gas neutral andresource-efficient Germany –GreenSupreme(UBA 2019)

1. Agora Energiewende,
Agora Verkehrswende,
Stiftung
Klimaneutralität

GJETC: Long-term scenario analysis

Organization characteristics

Central environmental authority of
the Federal Republic of Germany
and part of the portfolio of theFederal Ministry for theEnvironment, Nature Conservation,
Nuclear Safety and Consumer
Protection. Primary task: thescientific support of the federal
government, the enforcement ofenvironmental laws and theprovision of information to the
public on environmental protection
based on independent research.

53. Climate policy and energy transition targets for2045/2050
Authors: Institute of Energy Economics, Japan and Wuppertal Institute for Climate,
Environment and Energy

3.1 Japan (2050)
In 2020, the Japanese government declared its objective to reduce greenhouse gas
emissions (GHG) by 46% by 2030 over 2013 levels, and to reach net-zero by 2050. GHG
emissions in 2018 amounted to 1.06 billion tons including emissions from the power
sector (440 million tons), buildings (110 million tons), industry (300 million tons), andtransport sector (200 million tons). Apparently emissions from the power sector are
responsible for a large portion of total emissions.
In Oct 2021, the 6th Strategic Energy Plan was published by the Japanese government.
The plan describes the major direction of the strategy on energy demand and supply forthe timeframe 2030 until 2050. Japan’s energy use accounts for over 80% of greenhousegas emissions and thus the plan presents key information on how to reduce the GHG
emissions in the energy sector: Based on assumptions related to the expected renewableenergy installations or demand, the plan shows a concrete energy supply/demandbalance and power sector energy mix in 2030 while also presenting related policies andmeasures. The 6th Strategic Energy Plan describes that apart from utilizing renewable andnuclear energy, technology innovation for hydrogen/ammonia power plant and CCUS
should also be pursued. As for the non-power sectors like transportation and buildings,
electrification should be expanded.
Thus, the Japanese government considers various options to realize carbon neutrality by
2050 while also considering the compatibility with a stable energy supply and reducing
the national economic burden. On the other hand, the plan does not show a concrete
scenario for 2050, but only describes the intended broad direction of Japan's energy
policy towards 2050. This is due to the fact that an outlook on 2050 depends on several

GJETC: Long-term scenario analysis

6

factors such as technology innovation or future energy demand, both remaining
uncertain.

3.2 Germany (2045/2050)
In April 2021, Germany experienced a ground-breaking step in its climate protection
legislation, when the Federal Constitutional Court (German: Bundesverfassungsgericht,
BVerfG) ruled that the German state was obliged to prevent any future disproportionate
restrictions in the fundamental liberties of today’s young generation (Constitutional
Court 2021, 1 BvR 2656/18) and by that forced the government to take immediate
action. Thereafter, the targets of the climate law from 2016 were tightened so as toachieve greenhouse gas emissions neutrality no later than 2045, with interim targets forgreenhouse gas reductions until 2030 (-65% compared to 1990) and 2040 (-88%compared to 1990). In addition, the sector targets for the energy, industry, transport andbuilding sectors until 2030 have also been tightened (see table 3) and will be further
specified in 2024 and 2032. It should be noted that the sector targets are binding for the
responsible ministries, and a rigorous enforcement mechanism was decided in case thatthe reduction trajectories are missed.

Table 3: Annual emission budgets for sectors according to the German climate protection law [Million t CO2eq]
Annualemissionbudgets inmilliont CO2eq

2020

2021

2022

2023

2024

2025

2026

2027

2028

2029

2030

Energy

280

*

257

*

*

*

*

*

*

*

108

Industry

186

182

177

172

165

157

149

140

132

125

118

Buildings

118

113

108

102

97

92

87

82

77

72

67

Transport

150

145

139

134

128

123

117

112

105

96

85

Agriculture

70

68

67

66

65

63

62

61

59

57

56

Waste andothers

9

9

8

8

7

7

6

6

5

5

4

Source: Climate Protection Law 2021

GJETC: Long-term scenario analysis

7

Details of the climate protection law shall be improved in accordance with EU legislation.
The same holds true for the national CO2 pricing instrument that, from 2024 on, shall be
adjusted according to the actual development of the expected EU regulation so as toimprove coordination of national measures with European strategies (Climate Protection
Law 2021, DS 19/30230).
In general, as a Member State of the European Union, Germany’s energy and climate
policy is deeply influenced by the regulations of the EU. With the European Green Deal,the EU proclaimed that it will become the first climate-neutral continent by 2050 (TheEuropean Green Deal 2021, COM (2019) 640 final). This general target has been specified
in the fit for 55-package, aiming at a GHG emission reduction of 55% by 2030 andforeseeing a number of legislative proposals with which the EU seeks to encourage and,in some parts, require Member States to tackle global warming (ibid).
Following the German parliamentary elections in September 2021, a new government
consisting of the Social Democratic Party, the Green Party and the Free Democratic Partycame into office. Their coalition treaty proclaims a highly ambitious acceleration of green
electrification and aims at 80% renewable energy coverage of gross power demand by2030 while ‘ideally’ phasing-out coal in that same year, in addition to the nuclear phaseout in 2022. To secure these goals in all federal states, a challenging target was set toreserve 2% of the total area of each federal state for onshore wind power. Other
noteworthy plans include the highly ambitious increase of renewables in heatingbuildings (50% up to 2030; any new heating systems from 2024 onwards shall use atleast 65% of renewable energy) as well as the goal to achieve a total of 15 million allelectric vehicles by 2030. In the same year, 10 GW of domestic electrolysers forhydrogen production shall be established to be fed by offshore wind power andsupplemented by a high imported volume of green hydrogen. With the exemption ofsome proposed measures for the building sector, energy efficiency does not play a very
prominent role in the coalition treaty but will continue to be part of the implementationof Germany’s Climate Protection Law.

GJETC: Long-term scenario analysis

8

4. Analysis of the Japanese scenarios
Author: The Institute of Energy Economics, Japan

4.1 Methods used and key assumptions
4.1.1 Model comparison
In Japanese scenarios, almost all scenario studies use models to minimize total energy
system costs including capital costs and variable costs (among others). It should be notedthat although the basic approach of each model is similar, the definitions of costs can bedifferent in each model.
These models must be understood not as forecasts, but as back-casting models assuming
carbon neutrality by 2050 as a model restriction. Hence, these scenarios do notnecessary assure that carbon neutrality is technically or economically feasible but draw apicture or indicate net zero issues under several conditions.

Table 4: Model comparison (Japan)

RITE
Model

Objective

NIES

REI

Dynamic New
Earth 21+
model

Integrated
LUT Energy
model
System(generalTransition
equilibrium/
modellingbottom-up/
generation
mix)
Minimizing total energy system costs(capital cost, variable cost, etc...)*

Deloitte

IEEJ

IEA TIMESModel

IEEJ-NE
model

Temporalresolution

1 hour

1 hour

1 hour4 hours per
4 seasons

1 hourSpatialresolution

1 node10 nodes9 nodes

351 nodes

5 nodes

GJETC: Long-term scenario analysis

94.1.2 Macro framework
Almost all models’ macro frameworks include population, GDP, service demand, etc.
(table 5). These assumptions may affect the final energy consumption. However, thedifference of assumptions among the models is small. As for fuel prices, many models
refer to the World Energy Outlook 2020 (WEO 2020) published by the International
Energy Agency (IEA). Hence, assumed fuel prices are also similar among the models.

Table 5: Macro framework in Japanese model assumptions

Population in 2050
[million]
Households in 2050
[million]
GDP growth rate[%/year]
Crude steel production
in 2050 [million t]
Cement production in
2050 [million t]
Ethylene production
2050 [million t]
Paper production in
2050 [Mt]
Passenger in 2050
[Trillion p-km]
Freight in 2050 [Billion
km]
Coal price (2040)[USD/t]

RITE

NIES

REI

Deloitte

IEEJ

Min

Max

96-122

101.9

101.4

n.a.

n.a.

96

122

n.a.

47

n.a.

n.a.

52

47

52

-0.1 ~ 1.2

0.5

n.a.

n.a.

1

-0.1

1

73-111

85.7

n.a.

n.a.

119.7

73

119.7

31-75

60.4

n.a.

n.a.

43.4

31

75

n.a.

5.4

n.a.

n.a.

4.4

4.4

5.4

n.a.

23.5

n.a.

n.a.

21.2

21.2

23.5

0.64-0.82

1.18

n.a.

n.a.

1.23

0.64

1.23

n.a.

419

n.a.

n.a.

457

419

457

54

61

53

76

54

61

61

61

WEO2020

0.89
JPY/kWh
Crude oil price (2040)
76
53
3.45
[USD/barrel]
WEO2020
JPY/kWh**) 115 JPY = 1 USD, 0.88 EUR = 1 USD; n.a. = not available

WEO2020

WEO2020

53

53

WEO2020

WEO2020

4.1.3 Renewable energy capital cost
All models use capital costs of renewable energies as a parameter. However, capitalcosts are significantly different depending on whether domestic or international costs
are assumed.

GJETC: Long-term scenario analysis

10

As for PV systems, NIES inserts the smallest capital costs among the models. The capitalcosts are international costs estimated by IRENA 2019. REI also uses international costs
estimated by ETIP-PV1 and Vartiainen 2019. The cost developments are estimated by alearning curve with a learning rate of 40%, which is larger than typical learning rates (E.S.
Rubin et al. 2015). Deloitte estimates the highest capital costs among all models. The
capital costs referred mirror the current costs estimated by the Japanese cost working
group. IEEJ inserts capital costs by assuming a learning rate of 21% for PV modules and alearning rate of 15% for domestic balance of system (BOS) costs including racking or
wiring. RITE shows approximately 50-150 USD/MWh of LCOE in 2050 instead of capitalcosts. The range arises from the difference of irradiance in each area.
As for onshore and offshore wind systems, NIES uses the smallest capital costs amongmodels. The capital costs are international costs estimated by IRENA 2019. REI also
assumes international costs estimated by E3 for PRIMES2 and EC. Deloitte refers to thehighest capital costs among the models in line with the current domestic costs estimatedby the Japanese cost working group 2021. IEEJ estimates capital costs by assuming alearning rate of 8% for wind turbine and a learning rate of 7% for domestic BOS costs.
RITE shows approximately 70-180 USD/MWh of Levelized Cost of Electricity (LCOE).
Currently, there is a gap between international costs and domestic costs, both for PV
systems and onshore wind energy systems, due to technical particularities related totyphoons or earthquakes that are reflected in the domestic costs. For example, PV
systems must use stronger racking systems against strong wind. Moreover, the design ofwind towers can be different from the wind tower installed in Europe, because Japanese
towers must be able to withstand earthquakes. Hence, technical particularities arechallenges for the conversion of domestic costs into international costs.

1

Concrete publication title was not shown. For further information: https://etip-pv.eu/

2

Concrete publication title was not shown. For further information: https://e3modelling.com/

GJETC: Long-term scenario analysis

11Figure 1: Assumed capital costs for PV and wind energy in 2050 [thousand JPY/kW]

a: PV system

Capital cost [thoushand
JPY/kW]

350
300
250
200
150

100
50
0

IEEJ

Deloitte

REI

NIES

NIES

REI

REI

NIES

b: Onshore wind
Capital cost [thoushand
JPY/kW]

350
300
250
200
150
100
50
0

IEEJ

Deloitte

c: Offshore wind
Capital cost [thoushand
JPY/kW]

1200
1000
800
600
400
200
0

IEEJ

Deloitte* 100 thousand JPY ≒ 77 EUR* RITE shows LCOE (PV: approx. 50-150 USD/MWh, Wind: 70-180 USD/MWh) instead of capital costs.

GJETC: Long-term scenario analysis

124.1.4 Solar and wind energy potential
Since almost all Japanese contiguous land is covered by forest, the estimated solar andwind energy potential is a key factor to influence the energy mix. The assumed potentialsof these energies are significantly different depending on the installation sites (such as
farmland and forests), and on the rules for zoning of offshore wind. These assumed
potentials make a big difference among the model results especially for the energy mix in
2050.
As for PV systems, REI assumes the highest potential (2,746 GW) by referring to thereport by the Japanese Ministry of Environment (MoE) 2021. Due to this estimatedmassive potential, the large majority of it is assumed to be installed on farmland (2,365
GW). Due to the Japanese agricultural law, PV systems installed on farmland must ensure
enough space between PV modules to ensure sufficient crop radiation. If the agricultural
production is significantly reduced after installing a PV system, the permission ofagricultural land conversion will be revoked.
NIES and IEEJ assume a potential of approximately 360 GW for PV systems. This potential
is assumed by installations on the roofs and walls of buildings and installations on
weedland and devasted land. RITE sets an upper limit of generated electricity (750TWh/yr.) instead of installed capacity.
As for on-shore wind energy systems, REI assumes the highest potential (285 GW) by
referring to the report by the MoE 2021. However, most of these installations are
assumed to be in the forest where the annual average wind speed is ≥ 5.5 m/s(approximately 250 GW). Currently, local governments tend to regulate installations inforests to conserve the local nature or environment. Excluding the potential installation
areas which may cause a negative impact to the local environment such as forests, only
23 GW of on-shore wind energy is possible to be installed (Obane et al 2020). Following
this fact, IEEJ assumes two potentials depending on whether local environments are
considered (Base scenario), or not (RE100+ scenario).
NIES assumes a potential (118 GW) that takes into consideration not only technologicaland legal restrictions, but also economic restrictions by referring to the report of the

GJETC: Long-term scenario analysis

13

MoE 2011. In the MoE report, the potential taking into consideration only technical andlegal restrictions is 285 GW. If economic restrictions are further considered as well, theremaining potential is 118 GW. These potentials do not take into consideration local
environments. RITE sets an upper limit of generated electricity (200 TWh/yr.) instead of
installed capacity.
As for offshore wind energy systems, REI assumes the highest potential (1,120 GW) by
referring to the report of the MoE 2021. The scenario assumes installations in all areas
where the annual average wind speed is ≥ 6.5 m/s, the water depth is < 200 m, and the
distance from shore is bigger than 30 km, while national parks are not included. NIES
assumes the potential that considers economic restrictions in addition to the abovementioned sea use restrictions (177 GW). However, offshore wind energy systems cancurrently be installed in areas (promoting zones) that are determined by zoning rules. For
example, a promoting zone can be determined within the Japanese territorial waters(according to the international sea water jurisdiction within a radius of 22.2 km) byconsidering natural conditions, shipping routes, grid connection, among others.
Accordingly, the base case of IEEJ assumes a potential of 405 GW by considering thesezoning rules (Obane et al. 2021). However, this potential includes areas restricted byfishery rights or near the shore areas where the sea scape is possibly destroyed by a lotof turbines.
Figure 2: Assumed solar and wind energy potential in Japan in 2050

GJETC: Long-term scenario analysis

144.2 Key results
4.2.1 Primary energy supply in 2050
In 2020, the primary energy supply from fossil fuels accounted for 85%. Moreover, oilenergy supply accounted for 38% of the total primary energy supply because oil was
mainly used for transportation. On the other hand, all scenarios show that the primaryenergy supply from fossil fuels in 2050 will be significantly reduced as a result of cost
optimization when carbon neutrality is assumed in back-casting models. Instead of fossil
fuels, renewable energy, hydrogen, ammonia, and nuclear are assumed to fill the gap for
securing the primary energy supply.

Figure 3: Primary energy supply in Japan in 2050 [TWh]
6000

100%
80%
70%

4000

60%

3000

50%
40%

2000

30%
20%

1000

10%

Actual

RITE

NIES

Oil
NuclearElectricity(Import)

Coal
H2/Ammonia
Unutilized

REI Deloitte

RE100+

Base+

RE100

Nuclear

CCS

Base

RE

Cost min

RE100

SocialTechnology

DemandCCUS

Hydrogen

NuclearInnovation

RE100

Base

0%

2020

0

IEEJ

Gas
Renewable% of fossil fuel* As for REI, final energy supply is referred to. Hence, the total energy supply is not necessarily
consistent to the other results.

GJETC: Long-term scenario analysis

15

Percentage of fossil fuel [%]Primay energy supply [TWh]

90%
5000

The scenarios that include the utilization of CSS indicate higher percentages of fossil fuels
in 2050, compared to the scenarios developed by NIES, where fossil fuels account for 1415% of the total primary energy supply. Moreover, the scenarios including the strong
utilization of renewable energy indicate smaller percentages of fossil fuels. REI shows
results for the final energy supply instead of primary energy supply. Although thedefinition is different from the other scenarios, REI’s scenario shows that final energy
supply from fossil fuels is reduced to zero by utilizing hydrogen.
4.2.2 Electricity generation mix in 2050
In 2020, the percentage of generated electricity from renewable energy was 20%. In
March 2022, only 10 of 60 nuclear power plants worked, and 24 out of 60 power plants
are determined to be shut down. Although the percentage of electricity from renewables
may be different among models, it is increasing to approximately 40-100% in 2050 (seeFigure 4). Here, the RE100 scenarios (RITE, REI, IEEJ) intend to achieve nearly 100%
renewable energy, according to the model calculations. However, the model results are
not necessarily the most cost-effective. If the RE100 scenarios are excluded, the average
percentage of renewable energy in electricity generation is 40%-70%.
The scenarios considering the use of nuclear energy estimate that existing nuclear power
plants should be fully restarted. Moreover, many models show zero emission thermal
power such as clean ammonia or CCS being utilized to cover the total electricity demandin 2050.
Some scenarios, including the RE100 scenario, show an extremely high percentage(>90%) of renewable energies. However, it should be noted that renewable energies inthese scenarios are assumed to be installed in restricted areas such as farmland orforests. For example, although the REI-scenario predicts a PV capacity of 524 GW, thiscapacity exceeds the potentials on buildings, weedland or devasted land (MoE 2021). In
order to achieve this capacity, approximately 200 GW of the PV system capacities need
to be installed on farmland. In this context, it is important to carefully consider the

GJETC: Long-term scenario analysis

16compatibility of the PV systems with the aforementioned restrictions related to theJapanese agriculture law (see chapter 4.1).
Figure 4: Generated electricity in Japan in 2050 [TWh]
120%
100%
1500
80%
1000

60%
40%

500
20%

ActualHydro/Geothermal
Onshore wind
Oil

RITE
Biomass
Solar
Coal

NIES

REI Deloitte
Wind
Nuclear
Gas

RE100+

Base+

RE100

Nuclear

CCS

Base

RE

Cost min

RE100

SocialTechnology

DemandCCUS

Hydrogen

NuclearInnovation

RE100

Base

0%

2020

0

Percentage of renewable energy [%]Generated electricity [TWh]

2000

IEEJ
Offshore wind
H2/Ammonia
ImportMoreover, achieving a capacity that exceeds 100 GW by onshore wind installations asassumed by many scenarios, requires onshore wind energy installations in forests.
Thus, although some scenarios show a high percentage of renewable energy, local
environment or social acceptance must be carefully considered if a massive installationof renewable energy is planned according to these scenarios.

GJETC: Long-term scenario analysis

17Figure 5: Comparison of installed renewable energy capacity with technical potential in Japan [GW]
Farmland

Building(Wall)500

Building(Roof)
400

Weedland

300
200
100
0

300

Installation capacity [GW]

Installation capacity [GW]600

Farmland
Forest250

Weedland
200
150
100
50
0

REI(RE100)

IEEJ(RE100) IEEJ(RE100+)

Potential

REI(RE100)(A) Ground-mounted solar

IEEJ(RE100+)

Potential(B) Onshore wind

Floating(Major conflict)
Bottom-fixed(Major conflict)
Floating(Moderate conflict)
Bottom-fixed(Moderate conflict)
Floating(Minor conflict)
Bottom-fixed(Minor conflict)

500

Installation capacity [GW]

IEEJ(RE100)

400

300

200

100

0

REI(RE100)

IEEJ(RE100) IEEJ(RE100+)

Potential(C) Offshore wind
* Potential is referring to MoE 2021, Obane et al. 2021, Obane et al. 2020.

4.2.3 Final energy demand in 2050
The final energy demand in 2020 amounted to 3,361 TWh and the percentage ofelectricity accounted for 27%. Most of the current final energy demand is covered byfossil fuels. Many scenarios show that the final energy demand is reduced toapproximately 3,000 TWh by 2050. This is mainly caused by the transition from oil to gas
or hydrogen by 2050. Since the total final energy consumption will be reduced by 2050,
the percentage of electricity will increase up to 40 – 50%. Although the percentage ofelectricity is higher, it should be noted that the absolute amount of final electricity
demand is not necessarily increased.

GJETC: Long-term scenario analysis

18Many scenarios show that the oil and gas demand will remain even in 2050 becausesome types of oil such as heavy oil must continuously be used for transportation.
According to the assumptions, the combination of gasoline cars and DAC may beconsidered cost-efficient comparing to electric vehicles. Accordingly, in some scenarios, acertain amount of gasoline cars is still estimated for 2050. Moreover, the use of CCS withgas power plants is estimated to be cost-efficient compared to renewable energies inmany scenarios, leading to a certain remaining share of gas power (see Figures 4 and 6).
These results depend on assumptions such as costs for CCS/DAC and fuel prices.

60%
50%

3000
40%
2000

30%
20%

1000
10%

ActualElectricity

RITE

Oil

Coal

Gas

NIES

REI Deloitte

H2

Other

RE100+

Base+

RE100

Nuclear

CCS

Base

RE

Cost min

RE100

SocialTechnology

DemandCCUS

Hydrogen

NuclearInnovation

RE100

0%
Base

0
2020

Final energy demand[TWh]4000

Percentage of electricity [%]Figure 6: Final energy demand in Japan in 2050 [TWh]IEEJ

Unknown% of electricity

4.2.4 Average costs in the electric power sector
All scenarios show the average costs in the electric power sector. It should be noted thatthe definitions of average costs are different among the models. For example, while REI
shows the lowest average costs, the value is defined as an average LCOE of all power
plants. NIES shows costs dividing the total of capital costs, O&M costs, fuel costs of all
power plants and storage by generated electricity. Deloitte shows average costs
depending on initial costs and variable costs of power plants, storage, and power grids.

GJETC: Long-term scenario analysis

19

IEEJ defines the average costs as the value obtained by dividing the total costs including
capital cost, O&M cost, fuels cost, by the annualized electricity demand of installed
power plants, storage, interconnection lines. Despite these differences of definitions, theaverage costs tend to increase as the percentage of renewable energy increases.
Figure 7: Averaged costs in the power sector in 2050 [JPY/kWh]By modelling, the IEEJ estimated the average costs in 2020 to 10 JPY/kWh

4.2.5 Storage capacity
While the percentage of generated electricity from renewable energy is expected to be
40-100%, some scenarios show extremely high percentages of renewable energy. These
results depend on the availability of hydrogen or the potential of electric vehicles toprovide flexibility to the power system. In these scenarios, backup power plants such as
thermal power plants with CCS and nuclear power plants tend to be excluded. Instead,these scenarios show a massive amount of storage capacities (> 1,000 GWh).
If 10 kWh storage systems were installed in all currently existing residential homes (29million), the total storage capacity would be only 290 GWh (10 kWh x 29 million).
Compared to this, the necessary storage capacity to assure electricity supply security issignificantly larger.

GJETC: Long-term scenario analysis

20

Figure 8: Storage capacity in Japan [GWh] in 2050

Capacity [GWh]

5000
4000
3000
2000

1000
0

Base RE100
RITE

RITE

RE100Cost min RE
NIES

REI

Deloitte

Base

CCS Nuclear RE100 Base+ RE100+
IEEJ

4.2.6 Main implications
As the model approach and assumptions by each organization are different, the main
results of each organization also differ.
RITE implies that various technologies and innovations such as hydrogen generation,ammonia generation and CCUS are necessary to reach carbon neutrality. Moreover,policy support for several fields is necessary. Similarly, IEEJ implies various options being
utilized for carbon neutrality such as nuclear energy generation, hydrogen generation,ammonia generation, and CCUS. Moreover, a balanced energy mix is required.
NIES assumes that the decarbonization may cause losses of national wealth.
Furthermore, social transformation may ensure/enable decarbonization. REI estimatesthat decarbonization is possible not only in the electricity supply but also in the heat andtransport sectors by utilizing renewable energies.
Deloitte assumes that a percentage of renewable energy of 71% in the electricity
generation may lead to a doubling of electricity prices compared to the current pricelevels for realizing carbon neutrality.
Thus, while some organizations stress the difficulty of achieving carbon neutrality in the
power sector and the need for various technologies, others assume that decarbonization
may give positive impacts.

GJETC: Long-term scenario analysis

21

5. Analysis of German scenarios
Author: Wuppertal Institute for Climate, Environment and Energy

5.1 Methods used and key assumptions
5.1.1 Scenario approaches, models and methods used
Most German scenarios are based on back-casting modelling approaches (policy
scenarios): The necessity of reaching carbon neutrality in 2045/2050 is presupposed
according to the Paris Agreement (2015) and a national just contribution to the global“well below 2 degrees”-target calculated by the so-called budget approach 3 . The
scenarios investigate technically and economically possible strategies to reach thepresupposed carbon neutrality target in 2045. Detailed information on the models usedin the selected studies was only partially available.
The climate neutrality scenario 2045 of the Agora study (in German: Klimaneutrales
Deutschland 2045, KN45; Prognos et al. 2021) is a diversified technology scenario. In
comparison to a former scenario analysis with the target year 2050, KN45 scenario relies
primarily on the rapidly accelerated and more comprehensive use of the alreadyprojected approaches of climate-friendly technologies and strong climate policies forclimate neutrality. The basic approach: energy efficiency, renewable energies andelectrification, green hydrogen and ca. 5% of negative emissions. The modelling of KN45
follows the same approach as the Agora scenario KN50 published in 2020 (Prognos et al.
2020). They are based on eight different sector models: the EU-wide electricity market
model, private household model, commercial and public sector model, transport model
TEMPS, agriculture model LiSE, LULUCF model FABio, waste model WaSMOD and theindustry model WISEE-EDM. The approaches differ in the various sectors and range frommerit-order modelling, including power imports and exports, in the electricity market
3 The budget approach starts with the calculation of the remaining global CO2-budget compatible with thetargets of the Paris Agreement and - by a per capita basis distribution – calculates the corresponding available
residual budget e.g. for Germany under certain probability assumptions
www.wbgu.de/fileadmin/user_upload/wbgu/publikationen/factsheets/fs3_2009/wbgu_factsheet_3.pdf).

GJETC: Long-term scenario analysis

22model to a bottom-up approach in the end-use sector models, modelled by end-use andfuels. The power demand resulting from the end-use sector models is converted to load
curves, including flexibility potentials, as an input to the hourly scheduling of power
plants according to their merit order.
Hence, this study models GHG emissions from all sectors, including the often neglected
sectors agriculture, waste and land use (Prognos et al. 2021: 23). The GHG emissions’assessment is based on the inventory report of the UNFCCC estimating a global warming
potential for 100 years for all greenhouse gases (4th Assessment report of the IPCC, IPCC
AR4).

According to the motto “Energy mix of the future: electrons and molecules”, the German
Energy Agency (dena) study (EWI 2021) generally relies on comparable four pillars as theAgora study, but with an emphasis on innovations and a higher share of hydrogen andother Power-to-X (PtX)4 fuels but less direct electricity use compared to the Agora study.
The authors emphasize additionally the importance of an integrated overall strategy witha holistic, political approach, CO2 pricing and social transformation. As all other studies, itis based on sectoral balance sheet limits that are in line with the German Climate
Protection Law (KSG21) (cf. chapter 3). Final energy consumption and greenhouse gas
emissions are calculated according to the source principle, attributing CO2 emissions to
specific countries and sectors in which they were generated. Equally to the Agora andBDI scenario, the GHG reduction targets of the Climate Protection Law (KSG21) are thecentral parameters for the modelling of the KN100 scenario. In 2030, the sectoral
reduction targets for the sectors of transport, industry, buildings and energy are each set
as quantity restrictions in the EWI5 energy system model DIMENSION, which optimizes
the future development of power plants, renewable energies and flexibility options(including electrolyzers) for the provision of energy in 28 European countries. In doing so,

4

Various technologies for storing or otherwise using electricity surpluses in times of oversupply of variable
renewable energies
5
Institute of Energy Economics at the University of Cologne.

GJETC: Long-term scenario analysis

23the model maps the cost-minimizing use and capacity expansions as well as thedismantling of various technologies. According to the EWI, the emissions of the
agriculture sector are not explicitly modelled in this study, but are rather taken from theresults in the Agora study.

The study of the Federation of German Industries (BDI) (BDI and BCG 2021) considers
Germany’s goal to reach GHG neutrality by 2045 the “greatest transformation in its postwar history” (Climate Paths 2.0 2021: 2, English summary) requiring fundamental
changes in the energy system (including the international energy supply), the building
and vehicle stock, infrastructure and large parts of energy intensive industries. Morespecifically, the authors mention the acceleration and intensification of energy-efficiency
measures as well as the green electrification, which necessitates a significant expansionof renewable energy capacities (by a factor of 4 in 2045 compared to 2019).
The BDI study does not explicitly explain the applied modelling approach. The authors
declare, however, that their “comprehensive, open to all types of technologies analysis”(Climate Path 2.0 2021: 1,2, English summary) is based on bottom-up approaches andrealized in dialogue with experts from specific industries and associations of the German
industry. The focus of the analysis lays on the calculation of investment and operation
costs concerning a broad range of mitigation technologies and measures.

The GreenSupreme Scenario of the German Environment Agency (UBA 2019) is the only
German scenario that focuses on both reducing THG emissions and the use of resources,
while combining technical options with sufficiency policies and behavioral changes. As it
was written in 2019, before the climate protection law was revised, it refers to climate
neutrality by 2050. Still, it is one of the most ambitious scenarios published in Germany.
Its strategies: (1) transformation of the energy system with a rapid shift to renewables
across all sectors and smart sector coupling, (2) ambitious energy demand reductions
through both energy efficiency and sufficiency (behavior), (3) conversion of emissionintensive industrial processes to low or zero-emission processes, (4) the reduction of

GJETC: Long-term scenario analysis

24

production volumes through circular strategies, but also lifestyle changes, and (5) the
substitution of fossil raw materials by secondary, biotic and lighter raw materials.
The scenario is based on different Input-Output models for each sector by considering
specific sector assumptions. For instance, to model the effect of resource efficiency the
URMOD model is used6.

5.1.2 Framework conditions and key assumptions
The German scenarios mostly focus on potentials, demand and replacement of existing
technologies in the energy, building, transport and industry sectors that constituterelevant factors for finding economic solutions on the way to climate neutrality. The
agricultural and waste or land use sector, land use or GHG emissions related to biomass
are only considered by the Agora and UBA studies.
In line with the revised Climate Protection Law 2021, the three recent studies refer tothe new more ambitious reduction targets (Climate Protection Law 2021, KSG). Although
the UBA study was published earlier and therefore is targeting on reaching climateneutrality only by 2050, its emphasis on a fast and strong reduction of CO2 emissions isapparent in its even stronger ambition until 2030 (-70%). Three of four scenarios assume
that the current demographic and economic development will be maintained (cf. table6). Only the UBA study follows a new path regarding the assumed economic growth.
While BDI, Agora and dena expect a constant or slightly declining GDP growth rate
ranging from 0,9% to 1,3% per year (2030-2050), the UBA study indicates a departurefrom the growth paradigm after 2030 by a growth rate of 0.7
The importance of market-based instruments for reaching climate neutrality isemphasized in all studies. However, only the BDI study provides explicit values of the CO 2
prices, both in the EU ETS context and in relation to the CO2 price regulated by the6

The average GDP growth rate from 1990-2020 was 1.3%, with a decreasing trend (1990-2000: 1.9%; 2000-

2010:0.9%; 2010-2020: 1.1%).

GJETC: Long-term scenario analysis

25

national Fuel Emissions Trading Act (German: Brennstoffemissionshandelsgesetz, BEHG)
for the sectors not covered by the EU ETS.8 According to the BDI study, the latter may
range from 65 €/t to no less than 150€/t depending on the policies that go along with it.

Table 6: Framework conditions assumed in German scenario studies

Indicatoryear

GHG reduction targets
compared to 1990 (in %)

2030

-65

-65

-65

-70

2045

-100

-100

-100

2050: -100

Population(number in million)

2020

83

83

83

83

2045

80

81

n.a.

74

Households(number in million)

2030
2045

43
43

n.a.
n.a.

n.a.
n.a.

n.a.
n.a.

GDP growth rate
(in %) per year

2018
2030
2045

1.3
ca. 1.0
ca. 1.0

1.3
0.9
0.9

1.3
1.3
n.a.

1.3
0
0

Primary energy demand(in TWh)

2018

3,646

3,646

3,646

3,646

Oil

2030
2045

34
31

45.8
60.6

29.88
n.a.

n.a.

Gas

2030
2045

20
22

17.9
23.7

13.3
n.a.

n.a.

Coal

2030
2045

8
8

10.3
10.2

6.5
n.a.

n.a.

EU ETS CO2 Price:
EUR2019/t

2030
2045

52
80

n.a.

72
n.a.

n.a.

Energy prices*)(EUR/MWh)

Agora
et al

Dena

BDI

UBA
(2050)*): Prices in the BDI study are inflation-adjusted with the reference year 2019. The other studies giveno further information about the inflation adjustment.

8

While the Agora study considers only the EU ETS prices under the current EU ETS system, the CO2-pricing
according to the BEHG even covers sectors beyond what is to be expected by the proposed new (expanded) EU
ETS (see BDI and BCG 2021: 43).

GJETC: Long-term scenario analysis

26

The German scenarios also include sector- and technology-specific assumptions onenergy efficiency and end-use technologies (see table 7).
Building sector
In the building sector, all studies assume a clearly increased renovation rate that
improves the energy efficiency of the building stock and rises on average up to 2% peryear in 2045 (compared to about 1% in the past). Again, the UBA GreenSupreme scenario
is more ambitious and assumes much higher rates, both in 2030 and 2045, achieving
even 3,6%. As an important condition for the decarbonization of the heating sector, allstudies consider the expanded use of heat pumps and expect their numbers to rise from
1,3 million to a maximum of 6 billion in 2030 and ca. 15 million units in 2045.

Transport sector
A basic assumption of all scenarios in the transport sector is its electrification. Startingfrom 516,518 all-electric vehicles in 2021, the analyzed scenarios expect between 9 and
14 million battery-electric vehicles in 2030. Regarding 2045, the studies assume that the
car stock is almost completely converted to BEV, however, they reveal different
assumptions about the size of the car stock. While Agora, dena and BDI consider
between 32 and 39 million all-electric vehicles in 2045, the UBA GreenSupreme-scenario
stands out with its approach of sufficiency: In addition to the 100% electrification
strategy of the motorized individual transport modes, the authors are clearly moving
away from the passenger car, but emphasize a modal shift towards environmentalfriendly means of transport such as public transportation, bicycle, pedestrian traffic. The
number of all-electric vehicles rises to only 18 million in 2050 in this scenario, because
the total number of individual vehicles is assumed to reduce by at least half.

GJETC: Long-term scenario analysis

27

Table 7: Key assumptions in German scenarios: sectoral assumptions

Indicator

Agora
et al

Dena

UBA
(2050)

BDI

Renovation
rate ofbuildings stock(in % per year)

2030

1.6

1.8

1.9

2.5

2045

1.7

1.9

2.1

3.6

Heat pumps
Number ofunits (% of heatin buildings)

2030

6 mn (24%)

4 mn

6 mn

n.a.

2045

14 mn (60%)

9 mn (42%)

15 mn (n.a.)

2050: 16 mn

Battery-electric
VehiclesNumber ofunits (% ofinventory
structure)2030

9 mn (19%)

9 mn (n.a.)

14 mn (31%)

12 mn

2045

34 mn (91%)

32 mn (n.a.)

39 mn (86%)

2050: 18 mn

Annual fullload hours
2030(on = onshore;
off = offshore)

PV

957

946

n.a.

n.a.

Wind

On: 1,888
Off: 3,600

On: 2,348
Off: 4,043

On: 2,122
Off: 3,786

n.a.
n.a.

PV

rooftop: 750
utility scale: 400

rooftop: 733
utility scale: 640

rooftop: 850
utility scale: 500

n.a.

Wind

On: 1,100
Off: 2,000

On: 1,038
Off: 1,920

On: 950
Off: 1,490

n.a.

Crude steel production
2045(in million t / a)

39.6

42.4

n.a.

34.5

Cement production
2045(in million t / a)

27.5

33.0

n.a.

17

Paper production 2045
(in million t / a)

25.1

24.1

n.a.

14

Investment
costs 2030
(in €/kW/2019)(75%)

GJETC: Long-term scenario analysis

28

Energy sector
Regarding renewable energies, the selected scenarios rather differ little in theirassumptions on full-load hours or investment costs. The dena and BDI studies appear tobe slightly more optimistic regarding wind energy. Regarding the investment costs forwind energy and photovoltaics, the scenarios assume different learning curve effects.
But they all commonly expect decreasing costs in the future.
Industry sector
In the industry sector, production volumes of crude steel, cement and paper are similar
between Agora and dena. A radical difference in the basic approach becomes apparent
when considering the numbers presented by the UBA GreenSupreme scenario: thestated quantities in the paper and the cement production are significantly lower andunderscore the immanent principles of sufficiency. As the BDI study only provides
numbers for 2030, it has not been considered further in comparing these indicators.

5.2 Key results
The German scenarios describe what pathways to climate neutrality for the various
sectors of the energy system could look like. In principle, there can be identified fourcommon approaches and basic strategies. However, each scenario has its own
characteristics and differences when compared to the others.
5.2.1 Reducing the energy demand
An ambitious reduction of the energy demand through efficiency measures in all sectors
is considered to be the first important pillar to reduce the GHG emissions. It is also abasic requirement to secure the energy supply through the extensive use of renewableenergy in all German scenarios. Efficiency potentials are seen especially in the building
and the transport sectors, where e.g. renovation, use of heat pumps, all-electric vehicles
lead to much higher degrees of efficiency. As a result, the final energy demand decreases
significantly from 2,500 TWh (2018) to 1,300-1,600 TWh in 2045 (1,600 TWh would be

GJETC: Long-term scenario analysis

29equivalent to approximately -36% in demand). The UBA scenario combines the energy
efficiency approach with resource efficiency and even reaches a final energy demand
reduction of -57% until 2050, to ca. 1,050 TWh in 2050. Primary energy is calculated tosee a 50% reduction between 2019 and 2045. Here, the BDI scenario achieves only 44%
of reduction (cf. table 8). Figures 9 and 10 overleaf show in addition, which resulting final
and primary energy mix is calculated in the German scenario studies.
Table 8: Energy demand reduction in German scenarios
Agora
et al

Dena

UBA
(2050)

BDI

Final energy demand
reduction(compared to 2018)

2045-36,1%-36,3%-36%

2050: -56,8%

Savings in primaryenergy(compared to 2018)

2045-50,8%-50,7%-44,2%

n.a.

It should be noted that the implementation of energy efficiency and energy conservation
policies up to now does not satisfactorily correspond with the partly ambitious energy
efficiency approach of the scenarios. Evaluations point out existing gaps between
possible efficiency potentials and scenario results, also when compared to the targets ofthe government9: “Between 2008 and 2019, final energy productivity improved by anaverage of 1.4 percent annually, which is well below the target of 2.1 percent annually”(8th Monitoring Report 2022: p.74, own translation). This indicates that not only forrenewable energy, but also for energy efficiency the ambition level of policy, industry
and the civil society must be raised to catch up with the path to climate neutrality as
demonstrated in all scenarios. Considering the assumptions for GDP growth rates shown
above, the scenarios would result in final energy productivity improvement rates ofaround 3 percent annually on average.

9

https://www.bmwi.de/Redaktion/EN/Publikationen/Energie/the-energy-of-the-future-8th-monitoringreport.pdf?__blob=publicationFile&v=6.

GJETC: Long-term scenario analysis

30

Figure 9: Total final energy demand and mix in German scenarios (in TWh)

4000
3500

2030

3000
2500

112
500
170

2000
1500
1000

134
549

2045

109

115
142

616

648

186

225

217

1022

934

962

1634

500
0
Statistics
2019

Agora

Dena

Fossil Fuels
Environmental Heat

BDI

206
545
465

85
121
138
148

226
138

96
147
158

524

727

724

822

580

282
143

280

229

207

286

UBA

Agora

Dena

BDI

UBA

Biomass
Synthetic Fuels

Electricity
Hydrogen

236
136
127

District Heat
Other Energies

Figure 10: Primary energy demand and mix in German scenarios (in TWh)

4000
3500
529
3000

TWh

2500

895
942

2000
1500

809

850

224

1253
711

726

1000
624

0

227
Statistik

586

712

754

Agora

Dena

BDI

2019

433

815
1516

500

596

Agora

2030

1165

1495

Dena

BDI

2045

Nuclear energy

Coal

Mineral oil

Fossil gas

Renewable

Other (e.g. waste)

Electricity trade

PtX-Import (incl. H2)

GJETC: Long-term scenario analysis

31

5.2.2 Transformation of the energy mix: Renewable energy and electrification
While the energy demand is decreasing, figures 9 and 10 also show that at the same time
there is a strong change in the energy mix. The scenario studies by Agora, BDI and UBA
suggest a phase-out of coal until 2030, 8 years earlier than what the former government
coalition decided in 2021.10 Nuclear energy will be phased out by 2022. The share ofother fossil fuels decreases to zero by 2045, meaning essentially 100% renewable energy
supply, including import of green fuels and, in some scenarios, electricity. Bothrenewable energy as an available, cost-efficient energy source11 and green electricity are
becoming increasingly important. Moreover, hydrogen and PtX fuels become relevant
after 2030.

Renewable energies
In all 4 scenarios, shifting the energy production to renewable energy sources is
considered to be the second major strategy towards climate neutrality. There is anadditional power demand for the domestic generation of green hydrogen and hydrogenbased PtX fuels as well as non-energetic uses in the industry.
The share of renewable energy sources in electricity generation increases from 44%(2020) to 60 to 86% in 2030 and almost 100% in 2045. The BDI study sets only 60% in
2030, because it assumes an even faster electrification, leading to higher total power
demand, while the UBA study with 86% is even higher, indicating a significantly fasterelectrification.12 It should be noted that the new government’s target of reaching a shareof 80% renewable power by 2030 exceeds the assumed share of renewables in three out

10

The new coalition actually seeks to phase-out coal until 2030.

11

See for estimates of cost developments e.g. the latest analysis by Transition Zerohttps://static1.squarespace.com/static/605b4bcc5526904ff5589918/t/62066db231110622409e34eb/1644588
483986/TransitionZero_Coal-de-sac_Report_final_full+report.pdf
12While the studies conducted by Agora and dena still consider a small amount of natural gas (Agora: 2%,
dena: 1%) in the electricity production of 2045, in the BDI-scenario the phase-out will be already completed
then. Also, contrary to Agora and dena, the electricity production refrains from net electricity imports in the
BDI study. The share of renewable energy in the net power generation including net power imports, in all 4
scenarios rises to 67-84% in 2030, and reaches 100% by 2045.

GJETC: Long-term scenario analysis

32

of the four studies analyzed here. The same is true for the electrification goals, e.g. thenumber of electric vehicles.
In regards to primary energy, the share of renewable energy increases from currently
16,4% (2021) to 31%-38% in 2030 and 93%-97% in 2045.13 Renewable energies such as
geothermal and solar thermal also play an important role in the heating and cooling
sector.
Germany will have to accelerate the expansion of renewable energy production
significantly. Figure 11 shows the annual gross increases until 2030, which will double oreven triple compared to the last years. The biggest annual increases are seen for PV (810 GW), wind onshore follows with 5-11 GW. This ambitious capacity increase
underscores that the restrictive upper limits of installation, zoning rules and spatialplanning of the past must be revised in favour of a very challenging expansion strategy.
The resulting electricity production capacities of renewable energies are expected toreach on average 140 GW for PV, 90 GW for wind onshore and 25 GW for wind offshore
until 2030 (cf. table 9). In the following phase up to 2045, the scenarios show different
dynamics: While Agora sees a further massive expansion of PV with 355 GW in 2045, theBDI-study and dena are more reserved with only 230-260 GW, UBA even expects only
130 GW of installed capacity. BDI sees the highest wind onshore potential, with 180 GW
installed capacities in 2045.

Most of the scenarios do not focus on price developments and integration costs inparticular, since they find that overall energy system costs will be more or less the sameas today. The GreenSupreme Scenario, for instance, describes the direction of pricedevelopments (as constant or as shifting slightly upward) but without any quantification.
However, based on the low-cost flexibility potentials that they identify, the studies do
not consider integration costs as a major challenge for reaching climate neutrality.
13

While the studies conducted by Agora and dena still consider a small amount of natural gas (Agora:
2%, dena: 1%) in the electricity production of 2045, in the BDI-scenario the phase-out will be alreadycompleted then. Also, contrary to Agora and dena, the electricity production refrains from net
electricity imports in the BDI study.

GJETC: Long-term scenario analysis

33

Table 9: Expansion of renewable energy and electricity system costs in German scenarios

Agora
et al

Dena

BDI

UBA
(2050)

Primary energy:
Share ofrenewables

2030

37.6%

33.1%

31.2%

n.a.

2045

97.0%

93.3%

n.a.

n.a.

Electricity
generation:
Share ofrenewables,
includinghydrogen andwaste fromrenewables
Installed
electricity
production
capacities (GW)

2030

70,8%

75%

59,9%

85,5%

2045

100%

100%

100%

100%

2030

PV: 150
Wind on: 81
Wind off: 25

PV: 131Wind on: 92
Wind off: 23

PV: 140Wind on: 98
Wind off: 28

PV: ca. 105
Wind on: 104
Wind off: ca. 16

2045

PV: 385
Wind on: 145
Wind off: 70

PV: 259Wind on: 124
Wind off: 50

PV: 230
Wind on: 180
Wind off: 70

2050: PV: 130
Wind on: 127
Wind off: 30

Difference inElectricity System
Costs(Eurocent/kWh,compared toreference)

2030

n.a.

n.a.

-0.1

n.a.

2045

n.a.

n.a.

+0.6

n.a.

According to BDI, such a vast expansion of renewable energy will cause power systemcosts amounting to 73-104 billion Euro (BDI and BCG 2021), related to the expansion of
the electricity grid (13 billion EUR), the accelerated expansion of renewable energies (13billion EUR) and the construction of “H2-ready” gas-run power plants (5 billion EUR).
These costs are estimated to be largely passed on to the end-users (ibid). However, theelectricity prices are expected to only rise slightly (+0.6 Eurocent/kWh in 2045), due toan overall increase of electricity demand related to new applications entering the market(see figure 13). Moreover, the authors of the BDI study assume that the renewableenergy levy will be abolished, leading to a considerable decrease of customer prices per

GJETC: Long-term scenario analysis

34

MWh (BDI and BCG, 2021). This assumption corresponds with the decision of the Federal
Cabinet of March 2022. 14
Expanding renewable energies in densely populated Germany will be a challenge
especially for onshore wind energy. Potential studies of the UBA (2013/2019) on thepossibility of increasing wind energy onshore (UBA 2019) show that, theoretically, there
is sufficient space (UBA 2013; UBA 2019a). But zoning rules, environmental and nature
conservation aspects, social restrictions and lengthy approval procedures pose an
obstacle so far. Further land use conflicts due to grid, storage, electrolysers and CCS/DAC
are to be expected. Considering environmental and nature conservation aspects, UBA
identifies an area of (roughly) 7,800 km2 to be available for onshore wind energy use, on
which an installed capacity of around 200 GW would be possible. This has not been
exhausted in any of the four studies. The same is the case for the Solar PV potential. The
solar PV generation potential in buildings alone has been estimated to be around 10
times higher than the use of PV calculated for 2050 in the German scenarios (Fath 2017),
and most of it is cost-effective.
Figure 11: Annual gross increases of wind and PV capacities in German scenario studies (in GW)

25Wind Onshore

Wind Offshore

20

16

Photovoltaics

15

17

15

10

GW

10
5

0

14

6
3
1
2

6

7

4
1
1

5

Statistics
2018

Statistics
2019

1

2
5

9

11

2

2

4
1

6

7

6

8

Statistics Agora et al
Dena
BDI
UBA (GS)
2020------- 2021 - 2030 (average) --------

https://www.bundesregierung.de/breg-en/news/renewable-energy-sources-act-levy-abolished-2011854.

GJETC: Long-term scenario analysis

35

Electrification
Technology shift and the electrification in all sectors, especially transport, building andindustry sector enables displacement of conventional fossil energy sources. It thus
represents an important and particularly efficient strategy to decarbonization. The shareof electricity contributing to the total final energy demand increases in almost all
scenarios from 20% (2019) to ca. 41-51% in 2045 (cf. figure 9). Particularly the expansionof electric vehicles, heat pumps and electrolysers for the ramp-up of green H2
production, but also the stronger use of other power-based processes in the industry
contribute to the increase in power demand (see figure 13). Differences in the assumed
growth in these numbers among the 4 scenarios are also reflected in the results, showing
different quantities of net power generation needed. The net power generation will
nearly double from ca. 540 TWh to ca. 1,000 TWh between 2019 and 2045 (see figure
12).
Figure 12: Net power generation by fuel plus power imports (w/o pumped hydro and batteries) in Germany(in TWh)
1300

TWh

700

540

500

87

100

2

774

900

300

1061

1031

1100

673

632

137

134

52

105
71
46
99

139
90
151

Statistics

Agora

194

565
90

355

868

46

65

240

740

235

292

130
130

440

430

BDI

UBA
(2050)

123
93

137
106

105
75

252

199

216

208

270

309

303

Dena

BDI

UBA
(2050)

Agora

Dena

-100

2019

2030

Wind Onshore
Biomass
OthersWind Offshore
NuclearNatural gas

GJETC: Long-term scenario analysis

2045
Photovoltaics
LigniteHydrogenHydro power
Hard coalNet electricity imports

36

Figure 13: Power demand of “new” uses of electricity in German scenario studies (in TWh)

Agora…

62

30

Dena

43

27 14

BDI
UBA

30

30

72

48

31

63

Agora…

68

160

Dena

98

BDI
62

0

191

38
163

UBA…

150

52

155

72
249

48
100
Electromobility

200

300
Heat pumps

400

500

TWh

Electrolysers

5.2.3 Hydrogen and PtX as energy source and raw material
However, renewable energy and electrification alone will not be enough to decarbonize
the economy. In some fields gaseous and liquid energy sources will still be needed, sothat the decarbonization of the industry, the energy and the transport sector in Germany
also strongly depend on an increasing use of hydrogen and PtX. Hydrogen will be used
for 5 to 10 per cent of power generation (e.g., during ‘dark doldrums’), Direct Iron
Reduction in steel production, as raw material in the basic industry, for process steam
generation and for heavy freight, fuel cells of trucks and semi-trailers. PtX will beespecially used in international shipping and air traffic, thus reaching a significant
importance in 2045.
Figure 14 shows the hydrogen and PtX synfuels demand in 2030 and 2045 and it
illustrates a considerable big range of expected demand and production or importamounts. This is an area, in which the four scenario studies differ most widely. The dena
study estimates the highest demand, both for hydrogen (458 TWh) and synfuels (656TWh) in 2045, most of which would have to be imported, while the UBA GreenSupreme
scenario considers much lower demand (Hydrogen: 88 TWh, PtX: 455 TWh) in 2045.

GJETC: Long-term scenario analysis

37While all studies emphasize that the domestic hydrogen and synfuel production would
be preferable, it is mostly assumed that Germany will continue to be an energy importcountry. To meet the GHG emission reduction goals and ensure the financial feasibility,
significant imports will be needed: for hydrogen between 60 and 90% (130-400 TWh/yr),
for PtX ca. 77-90% (320-600 TWh/yr). Only the UBA GreenSupreme scenario considershydrogen to be fully produced domestically by 2045. This needs to be related to theoverall lower energy demand that the UBA GreenSupreme scenario assumes, according
to which the domestic green power potentials would be sufficient to cover the greenhydrogen production. Samadi/Lechtenböhmer (2022) underline, however, that theenergy imports in 2045 will be 70 percent lower than today´s imports of fossil energy
sources.
Figure 14: Hydrogen and PtX-Synfuels demand in Germany
700

700
Domestic
Import

500

60

400
300
200
100
0

19
44

10
56

43
0

Agora Dena BDI

Domestic
Import600

Demand [TWh]Demand [TWh]600

96 398

98

169

138

52

UBA Agora Dena BDI

2030

2045

500

109

400

UBA

300

596
433

200

0

84

96

327

100
88

60

19
45

10
60

46
54

371

0
63

Agora Dena BDI UBA Agora Dena BDI UBA
2030

2045

Since hydrogen for the time being will be mostly imported, the price will depend on theregion of origin and the means of transport. Figure 15, extracted from the dena study,
illustrates the respective price differences arising for imported hydrogen: Countries
outside Europe often have better conditions for renewable electricity production.
However, the more favorable production conditions are countered by longer distances
for hydrogen transport. Especially for distant countries, from where hydrogen will need
to be transported to Germany by ship, transportation costs account for a large share of

GJETC: Long-term scenario analysis

38the total hydrogen import costs. The import via pipelines from Eastern Europe, North
Africa, Middle East appears cheaper than by ship from South America, Middle East andAustralia. Accordingly, the price range fluctuates. Finally, geopolitical considerations
must be taken into account as well, as the current situation in Eastern Europe painfully
shows.

It is commonly agreed in all studies that green hydrogen production has to be pursued.
Natural gas will drop to almost zero in 2045. Accordingly, in 2045/2050, almost all gas for
power plants has to be green hydrogen to reach carbon neutrality. This implies thatpower plants that may still be fed by natural gas in the period 2030 to 2045 must alreadybe constructed “hydrogen-ready” to convert them gradually to hydrogen.
In addition to the optimized use of biogenic energy sources, the studies project a needfor further engagement in the national and international market development ofhydrogen and PtX synfuels.

Figure 15: Hydrogen import costs to Germany by region in 2045 (dena 2021)

5.2.4 Removing residual greenhouse gas emissions
It is expected that despite all measures and efforts, some greenhouse gas emissions
particularly in the agriculture, industry and waste sectors, will remain inevitable. For
2045, the analyzed scenarios expect residual emissions of about 43 to 87 billion tCO2eq

GJETC: Long-term scenario analysis

39

(cf. Figure 16). These amounts range from about 5 to 10% of the emissions in 1990, andcompensation appears feasible. But the relevance of technical and/or natural sinks is
considered quite differently across scenarios. Especially the authors of the Agora and BDI
study claim that the use of direct and indirect carbon capture technologies needs to bepracticed earlier and with more emphasis. Most of the scenarios emphasize BECCS as amain strategy. Dena and BDI also assume some CCS for natural gas, and BDI considers
DACCS as the most important option.
The GreenSupreme Scenario does not focus on technical measures for carbon dioxide
storage (CCS), because CCU is considered to be required for the provision of electricitybased hydrocarbons (in PtG/PtL technologies). But since national priority is given to the
production of hydrogen for industry, the nationally produced PtG quantities are limited
and thus also the need for CO2 sources. Instead, the GreenSupreme focuses solely on
natural sinks. Also, the dena study states natural sinks as a major option.
Figure 16: Technical and natural negative emissions 2045 (in million tCO2eq)[Million CO2eq t]

100

0

63

87

-11

-36
-1
-20

70

Green Feedstocks(Naphta, green polymere)
DACCS

43

-11

-41

-11
-9

-17

-39

-7

-7
-10

Agora

Dena

BECCU/S (Energy sector)
BECCU/S (Industry)

-43

CCS
Natural sinks / LULUCF
Residual GHG/CO2

-12

-100

GJETC: Long-term scenario analysis

BDI

UBA

40

6. Japanese-German Comparison
Authors: The Institute of Energy Economics, Japan and Wuppertal Institute for Climate,
Environment and Energy

The selected scenarios in both countries follow a back-casting approach, seek to reacheconomic solutions with a focus on cost efficiency and are assuming similar framework
conditions. Identified common strategies to reach climate neutrality are the reduction ofenergy demand through improved energy efficiency, the shift in the energy mix towards
climate neutral energy carriers, the electrification of energy end uses, and thecompensation of residual GHG emissions through technical sinks. However, details,characteristics and targeted shares differ, as shown below.

6.1 Improving energy efficiency
Japan: The primary energy demand on average decreases about 33%, only REI is more
ambitious with a reduction of 50% until 2050 (from ca. 5,100 TWh in 2020 to a range of
4,700 (NIES) to 2,000 TWh (REI)). The final energy demand decreases by 30% (from 3,361
TWh to approximately 2,500 TWh). The analyses of the demand side are not sufficiently
shown by current studies. In the future, it is recommended to assess theimpact/potential on the demand side in more detail.

Germany:

Improvingenergyefficiency

is

a

key

point

to

reduceCO2.

In the analyzed scenarios, the primary energy demand between 2019 and 2045
decreases on average by 50% (from 3,557 TWh to a range of 1,883 to 1,794 TWh), with
the BDI scenario achieving a slightly lower reduction of 44% (2,003 TWh). The final
energy demand in the analyzed scenarios decreases between 2019 and 2045 by 36%(from 2,484 TWh to a range of 1,604 to 1,572 TWh), whereas for the UBA scenario thathas a special focus on energy efficiency and sufficiency, it even reaches a decrease of
57% (down to 1,056 TWh in 2050). Potentials must be fully exploited according to the

GJETC: Long-term scenario analysis

41

UBA scenario, even if this may exceed the current targets and strategies of thegovernment.

6.2 Energy mix
Japan: Concerning the primary energy mix, the Japanese scenarios differ. The share offossil energy decreases from 85% (2020) to 0-10% (REI, NIES) or 40-50% (RITE, IEEJ
scenarios with CCS) in 2050. The share of renewable energies in the generated electricity
mix rises from 20% in 2020 to 100% (REI) or 40-70% for the other scenarios. The
installation of renewable energies is limited because of land use restriction. If a massive
expansion of renewable energies should be adopted, renewable energy sources would
have to be installed in restricted areas such as forests or farmland.
In contrast to Germany, nuclear energy is also considered as a supporting energy carrier
towards climate neutrality by most scenarios. In addition, final energy consumption fromgas and oil remains for transportation or industries, including steel or chemical. The
residual greenhouse gas emissions are compensated by using DAC and CCUS.
In many Japanese scenarios, electrification is determined as a model result while somescenarios may consider electrification as an assumption. If marginal electricity costs arelower than the costs for other technology combinations such as gas + DAC or gasoline +DAC, electrification will tend to increase. Many scenarios show the share of electricity infinal energy demand also increasing up to 40–50%, since the total final energy
consumption is reduced by 2050.

Germany: In German scenarios, the share of renewable energies in primary energy rises
to 95%, and to 100% in electricity production by 2045. Thus, compared to Japan, theinstallation of renewable energies is significantly higher. In order to achieve this, massive
additional capacities of on- and offshore wind power (174-250 GW) and PV (119385 GW) are needed. The higher numbers consider the available potential for windenergy in Germany, but not the complete PV potential, because it does not fully include
e.g. building-integrated and agri-PV.

GJETC: Long-term scenario analysis

42

The electricity supply-demand balance can be assured by all kinds of flexibility options
and some 5-7% of gas-fired power generation (including H2). Hydrogen from othercountries and from electricity by offshore wind is a key option to reduce CO2 in industry
and transportation. Nuclear energy is not included in the model assumptions, because
the German government decided on the nuclear phase-out to be completed by 2022. In
most scenarios, coal power would be phased out by ca. 2030.

6.3 Key technologies to fully reduce CO2 emissions
This section first relates to options used in the scenarios for fully reducing the energyrelated GHG emissions. Afterwards, options for emissions from other sectors are
discussed.

Japan: DAC (approximately 100-200 Mt CO2 per year) and CCS are considered key options
to reduce CO2 from e.g. gas power plants or furnaces in those scenarios that still see a
considerable share of fossil fuels in 2050. However, it is uncertain how much CO2 can be
stored by CCS (see also chapter 7.1.2). Other scenarios, such as REI, rely on hydrogen
imports instead of fossil fuels.

Germany: The import of zero-carbon fuels, such as green hydrogen and derived PtX fuels,
is a key option to meet the overall final energy demand. Maintaining the electricity
supply-demand balance depends on domestic flexibilities, domestic green hydrogen, andin some scenarios, limited net electricity imports. Nuclear power plants are generally
assumed in the models to be phased out by 2022.

While the Japanese scenarios stress the need to consider various technologies (including
nuclear energy) so as to ensure cost-efficiency and energy security, the German
scenarios underscore that energy security can go along with positive economic effects
and the impact of innovations, while phasing out nuclear and coal energy.

GJETC: Long-term scenario analysis

43

In addition to energy-related emissions, particularly in the sectors agriculture, waste
treatment, and some industrial processes it appears difficult, if not impossible, to fully
reduce GHG emissions, and the remaining emissions will need to be removed from theatmosphere through various technologies, such as those discussed in chapter 5.2.4. All
German scenarios, therefore, consider technical sinks as an inevitable strategy. However,
the envisaged quantities are relatively low. For about 5% of remaining GHG emissions,mostly from the non-energy sectors, natural sinks, BECCS and DACCS are the mostimportant options considered. Remarkably, the BDI puts emphasis on DACCS.

7. Shortcomings to achieving the net zero carbon target for2050 in Japanese scenarios and enhanced or new strategies
Author: The Institute of Energy Economics, Japan

7.1 Gaps
All Japanese scenarios assume achieving carbon neutrality in Japan by 2050. And allmodels focus only on Japan. Hence, none of the models shows any implication of the 1.5degree-reduction-target that must be achieved worldwide. In order to discuss thepossibility to reach the 1.5-degree, it is necessary to develop a worldwide model
assessment. Although it is difficult to discuss the worldwide potential to meet the 1.5degree-target based exclusively on this scenario comparison, to achieve the results
predicted by the models, it is important to analyze the gap between ideal scenario
results and reality.
7.1.1. Social acceptance for installation of nuclear and renewable energies
All Japanese scenarios consider either nuclear power plants or renewable energy asimportant power sources to achieve carbon neutrality. As for nuclear power plants,
almost all scenarios model only with existing nuclear power plants or those that are

GJETC: Long-term scenario analysis

44already in the planning. Only RITE and IEEJ develop scenarios allowing new constructions.
Although the scenarios show that new constructions potentially contribute to a
reduction of total integration costs based on model analysis, cost-analysis consideringsafety measures should be carefully evaluated, as German studies argue that theconstruction of new nuclear power plants in Germany is not cost-effective (DIW 2019). In
addition to this, social acceptance regarding restarting or constructing nuclear power
plants is a key issue to implementing these scenarios. Following the Fukushima accident
in 2011, many residents are opposed to restart nuclear power plants because of safetyconcerns.
The issue is raised not only for nuclear power but also for renewable energies. Many
scenarios show a massive installation of renewable energies to achieve carbon neutrality.
As a result, the percentage of renewable energies in generated electricity in 2050 isapproximately 40-100%. However, for achieving this capacity, PV systems or windturbines must be installed in restricted areas such as forests or farmland. Even foroffshore wind energy systems, wind turbines must be installed in the near shore area
which has a negative effect on the coastal landscape or is restricted by the fishery rights
in that area. In Japan, fishers have a strong legal basis to refuse developments in areas
covered by fishery rights based on the Fishery Act. For example, they have the right toclaim losses caused by development changes and seek injunctions. Therefore, developing
offshore wind energy in areas covered by fishery rights is impossible without the consent
from the fishers.
7.1.2. Potential of CO2 storage
Many Japanese scenarios assume utilizing CCS or DAC to capture CO 2 from power plants
or industry plants such as furnaces. The scenarios set the upper limit of CO2 capture
capacity at approximately > 1000 million t / year. The CO2 storage requires large areas ofland, but it is not clear, how big the CO2 storage potential on the Japanese territorial landor oversea is. If CCS or DAC could not be fully utilized as the scenarios show, more
electricity from renewable energy or electrification is required and total energy system

GJETC: Long-term scenario analysis

45

costs will increase. Thus, it should be noted that the feasibility of scenarios using CCS or
DAC depends on the potential of CO2 storage capacity.
7.1.3. Feasibility of massive installation of storage systems
The Japanese scenarios show that a massive installation of storage systems is required as
renewable energies increase (>1000 GWh). Even if 10 kWh storage systems were
installed in currently existing residential homes (290 GWh), the capacity cannot besatisfied with the required capacity to maintain hourly energy supply-demand balance.
Moreover, materials shortages are also a concern in regards to lithium. Hence, not only
economic feasibility but also the material supply risks of storage systems should be taken
into account.

7.2 Enhanced or new strategies to close the gap
Although many Japanese scenarios draw pictures of carbon neutrality by 2050 using
back-casting models, there is no scenario that convincingly proves the feasibility ofclimate neutrality by 2050. As described above, all scenarios have some kind of criticalissue such as social acceptance or the potential of CO2 storage. If a specific technology is
excluded in the scenario assumption, the number of possible strategies to achievecarbon neutrality is also limited. Hence, it is important to seek various low emission
technologies, not only renewable energies, but also to include nuclear power, CCS, DAC
and ammonia power plants. To come closer to the pictures drawn by the scenarios, thefollowing strategies are considered important.
7.2.1 Establishing a process to gain consensus from stakeholders
Given the estimated increase of nuclear power plants or massive installations ofrenewable energies in order to reach carbon neutrality, the need of social consensus will
increase respectively. However, a concrete process to gain consensus from stakeholders
or local residents has not been sufficiently established. Especially for PV systems or
onshore wind, there are no specific rules on how to take the opinions of stakeholders or
local residents into consideration. Hence, it is important for the feasibility of scenarios to

GJETC: Long-term scenario analysis

46

consider the question of how to reach consensus among stakeholders and/or local
residents to enable the massive installation of renewable energies or nuclear power
plants.
7.2.2 Consistency between local spatial planning and carbon neutrality
Up to now, some of the PV systems or onshore wind turbines — for instance, those inforests — proved to have negative effects on the local environment and wildlife /biodiversity. According to a report by the Japanese Forestry Agency, the total area of
deforestation attributable to the installation of PV systems is more than 90 km 2, which isequivalent to an installed PV power capacity of 6 GW (Japanese Forestry Agency, 2019).
In the case of onshore wind energy systems, 56% of systems installed after 2004 were inforests or wilderness areas (MoE 2011). Given these facts, the Japanese government now
considers spatial planning called “positive zoning” to determine those areas where only
few or no negative effects on nature through the installations of photovoltaic (PV)systems and wind turbines are to be expected. Therefore, the expansion of renewableenergies to the end of reaching carbon neutrality and the spatial planning that regulates
the installation are in a trade-off relationship. For example, many scenarios implying
renewable energy may have to be installed in restricted areas such as forests, but theseareas are possibly excluded from positive zoning areas. Hence, it is essential for decisionmakers who determine renewable energy targets to also take spatial planning into
consideration. Moreover, it is also important to develop agri-PV by ensuring crop
production and reducing the impact on the landscape.
7.2.3 Assessing the impact of non-power sectors for carbon neutrality
Many current Japanese scenarios focus on the power sector. However, non-power
sectors such as the industry sector and the transportation sector account for
approximately 50% of total CO2 emissions. It is thus important to also consider the nonpower sector when aiming at carbon neutrality. Hence, future scenario analysis should
also include key strategies for non-power sectors to approach carbon neutrality.

GJETC: Long-term scenario analysis

47

8. Shortcomings to achieving the net zero carbon target for2045 in German scenarios and enhanced or new strategies
Author: Wuppertal Institute for Climate, Environment and Energy

The German scenarios presented in Chapter 5 all underscore the technical feasibility ofachieving carbon neutrality by 2045 while presenting somewhat different pathways withvarying degrees of energy demand reduction, electrification, renewable energies, the useof hydrogen and hydrogen-based synthetic fuels, and carbon sinks.
The basic strategies in the German representative scenarios are comparable and can besummarized as follows.
▪

the nuclear phase-out will be completed in 2022;▪

coal-fired power generation must be phased out well ahead of 2038, ideally by 2030;▪

the expansion of renewable energies and, above all, renewable power generation is
massively accelerated;▪

the rate of energetic refurbishment of the building stock is increased considerably,and deep renovation must be achieved during retrofit processes; energy efficiency isalso increased in the industry sector, and some potentials of sustainable transport
are harnessed;▪

decarbonization of the transport, building and industry sectors takes place as far as
technically and economically possible through direct (green) electrification▪

the expansion of the hydrogen economy – with increasing proportions of imports(hydrogen and PtX) – plays an important role mainly after 2030.

Indeed, numerous scenarios also from other institutes, even with different technical andenergy policy positions, nevertheless reflect a broad scientific consensus on the technicalfeasibility of climate neutrality in Germany by 2045 with regard to the basic strategies. In
all scenarios, the phase out of nuclear energy in 2022 is assumed to be safely
manageable. The basic availability of less risky climate protection technologies to achieve

GJETC: Long-term scenario analysis

48

climate neutrality by 2045 is no longer in question in any scenario. Instead, thediscussion focuses on fundamental questions about the socio-economic relevance of thestrategies and scenarios as well as on the tension between scenarios, levels of ambition
and implementation, which will be addressed below.
In this respect, various shortcomings can be identified that could be resolved by anumber of additional strategies that should be considered in prospective studies.
Through a stronger analysis of the necessary policies and these additional strategies, thereliability of the scenarios and the confidence that carbon neutrality will be achieved inpractice by 2045 can be enhanced. They will make the rationale of highly ambitious
climate mitigation policies more understandable and acceptable for the public. On thisbackground and backed with additional analysis, it might be possible to achieve carbon
neutrality even faster than by 2045, eventually by around 2035.

8.1 Shortcomings of technology-focused German scenarios
The selected German scenarios are strongly focused on energy-related strategies and theassociated technical feasibility of decarbonization. A special focus is on the electricity
market and on the differentiated analysis of a renewable electricity supply. This isundoubtedly a crucial pillar of ambitious climate protection policy, but the essentialsocio-economic aspects are only addressed in the BDI study, while the behavioral aspects(e.g. rebound and growth effects or the opposite, more sustainable consumption
patterns) of an energy transition are not touched upon at all or only marginally in all
scenarios, with the exception of the UBA study.
8.1.1. Energy efficiency first

Energy efficiency plays an important role in all scenarios to reduce the overall demand.
Still, in most scenarios, the existing potentials, particularly in the transportation andbuilding sectors, but also in the industry sector, are not fully exploited. Hence, theprinciple of ‘energy efficiency first’ is not fully considered. Only the GreenSupreme
scenario of the UBA takes a larger potential into consideration. The combination of

GJETC: Long-term scenario analysis

49

material efficiency and circular economy strategies is also only partially pursued, e.g. by
the UBA study and to a certain degree by the BDI study. Without a policy integration ofclimate and resource protection, the strategy is biased towards supply-focusedelectrification strategies.
8.1.2 Socio-economic aspects

While technical feasibility is a crucial prerequisite of transformative paths todecarbonization, economic optimization of possible pathways is also important. However,in the selected studies, the simulation of macroeconomic effects is missing or only
carried out in the first steps. Moreover, challenges such as area restrictions related tothe estimated intensive installation of renewable power plants and the importance ofsocial acceptance are not fully anticipated in most studies. The same holds true formaterial restrictions related to PV and wind power (silicon, rare earths). With regard tosocial acceptance, distributional effects for households, companies and regions also
deserve closer attention in order to devise the necessary narratives of a just transition;
they are only analyzed to some degree in the BDI study. In this context, rebound andlifestyle effects (values, behavior), sufficiency policies and issues of change management(innovation/exnovation) also need to be shed light on. To date, only the UBA study
includes some of these aspects.
8.1.3 Policies for the actual implementation of the strategies
Most scenario studies conclude with a list of policies that are perceived as being able toreach the calculated scenario results. However, usually the studies do not directly model
the impact of concrete policy instruments and packages, which are needed to enable andincentivize both the technical and behavioral actions needed for the transition.
8.1.4 The ambiguous role of hydrogen
While the importance of including significant amounts of hydrogen and hydrogen-based
synthetic fuels is common ground among the studies, only little is said about thechallenges that come along with it: Neither do the scenarios present detailed concepts

GJETC: Long-term scenario analysis

50

on the necessary infrastructure, nor do they thoroughly discuss possible target conflicts
concerning (domestic and) imported hydrogen (e.g. perspectives of exporting
countries/global

competition/international

standards

forcertifying

greenhydrogen/synfuels).
8.1.5 Compliance with international commitments: how to reach the 1,5°C-target
Finally, the scenarios fail to explicitly discuss whether the ambition level and the strategies
they provide suffice to achieve the internationally agreed 1,5°C-target. The studies by Agora,dena, and BDI only focus on the analysis of if and how the carbon neutrality target for 2045
could be achieved. Applying the aforementioned budget approach (cf. chapter 5), theWuppertal Institute showed that the global CO2 budget compatible with the targets of theParis agreement demands for even more ambitious targets: As the graphic below illustrates,
Germany would have to reach climate-neutrality as early as 2035, because the remaining
CO2 budget of 4,200 tons would have been consumed by then.
Figure 17: Exemplary Emission Reduction path according to a German 1.5°C budget

Source: Wuppertal Institute 2020; based on SRU 2020

It must be emphasized that the study of the Wuppertal Institute (2020) as of today (March
2022) still is an initial illustration for Germany that has not yet been backed-up by acomplete scenario analysis. However, it highlights that Germany's contribution to a global
strategy “keeping 1.5 degrees within reach” requires a tremendous additional effort.
Nevertheless, the authors of the study sum up: “A climate-neutral energy system by 2035 is

GJETC: Long-term scenario analysis

51very ambitious, but fundamentally feasible if all strategies that are possible from today's
perspective are joined together” (Wuppertal Institute 202015).

Thus, the key challenge remains how the technology-focused strategies in the existinghighly ambitious scenarios must and can be combined with stronger policies or otherpolicy integration options, e.g. with sufficiency, circular economy/material efficiency, andstronger energy efficiency policies, to reach carbon neutrality ideally in 2035.16 It should
therefore be examined whether and to what extent the existing energy-related scenarios
can be linked and supplemented with corresponding quantified sub-scenarios, in orderto establish robust strategies for policy advice (see chapter 9).

8.2 Enhanced or new strategies to close the gaps
Corresponding to the aforementioned shortcomings, the following strategies aresuggested to be included in future scenarios and connected analyses: (1) the integrationof circular economy strategies, (2) the consideration of sufficiency policies, lifestylechanges, (3) just transition and public/social acceptance, and (4) the inclusion of policies
and policy integration in the modelling.
8.2.1 Integration of circular economy (CE) strategies
The integration of circular economy strategies into climate protection policies unfolds
significant synergies related to material and energy efficiency: Including the use of raw
materials into the scenario analysis would also help to avoid problem shifting to critical
metals and unsustainable extraction facilities. The technical potentials do exist, but every
kilowatt hour avoided through energy and material efficiency would facilitate the15

https://wupperinst.org/a/wi/a/s/ad/5169

16

A so called global „Societal Transformation Scenario (STS)“has been published recently: „The...results for the STS show alarge decline in energy demand in the Global North and a reduction of global GHG emissions of roughly 50% from 2020 to2030 and a further 22% (12.7 Gt CO2eq) by 2050. The cumulative CO2 emissions remain within the carbon budget that gives
us a 2/3 chance to staying within the temperatur increase of 1.5o C.“ (p.10). The assumed redistribution of wealth, power,
consumption and production might be utopian but it presents food for thought to analyze opportunities and risks ofincluding sufficiency policies into technically focussed scenarios. https://www.boell.de/sites/default/files/2020-12/A
Societal Transformation Scenario for Staying Below 1.5C.pdf?dimension1=division_iup

GJETC: Long-term scenario analysis

52expansion of renewable energy generation and particularly help to reduce the immense
implementation problems (e.g. space requirements, network expansion, resource
consumption, import requirements, acceptance).17
8.2.2 Consideration of sufficiency policies, lifestyle changes
To ensure a comprehensive analysis of the pathway towards climate-neutrality, socioeconomic aspects need to be considered. This includes values, change-management,
innovation and exnovation strategies. Most important societal topics of socio-economictransformation (e.g. behavior shifts, societal tipping points, mobility patterns, floor
space, living comfort, eating habits, reducing meat/dairy products, food waste, etc.)
sometimes cannot easily be included into existing modelling approaches. Also, atransformation of the agricultural sector with fewer livestock, more organic farming, anincrease of non-productive areas and biodiversity should be considered. The risk that ascenario-based “proof“ of the technical feasibility leads to wishful thinking andunrealistic target-setting should be avoided. For example, rebound effects, the inertia oflifestyles, or growth effects are a reality and they should be anticipated into scenario
assumptions and procedures as much as possible.
8.2.3 “Just transition” and citizen participation
The socio-economic transformation and enormous economic structural change on theway to carbon neutrality makes it imperative to anticipate possible detrimental or
supporting distribution and welfare effects. For example, carbon pricing will have aregressive impact on households and can induce carbon-leakage if not supported bycompensation measures. Also, wind power and huge ground-mounted PV might facestrong local opposition. But refunding a part of the revenues from carbon pricing,
citizens participation, financing and local benefit sharing can increase public acceptancefor the transformation. Thus, just transition should be a basic focus of scenario-related
analysis and it should be directly included into scenario assumptions and strategies.
17

Compare Acatech (2021), Circular Economy Roadmap for Germany; acatech/Circular Economy Initiative
Deutschland/SYSTEMIQ (Eds.) Update December 2021.

GJETC: Long-term scenario analysis

53

In Germany, for example, the coal regions and – foreseeable – the automotive sectors
are focal points of structural change. Thus, macro-economic analyses are of utmost
importance, but they should be combined with calculating net effects, e.g., for jobs,
added value, income and budgets referring to regional hotspots of economic structuralchange.

8.2.4 Analysis of policies and policy integration, and their inclusion in the modelling
Finally, the analysis of policies, which are needed to implement both, the technical andbehavioral actions needed for the transition, need to be included in the models to offer amore realistic view on whether and how targets can be achieved. In addition, policy
integration (e.g. heading for a sustainable and just mobility not only relying onelectrification or integrating the housing and the overall city planning) allows for acomprehensive view on the endeavor of reaching climate-neutrality. For example,
through the integration of comprehensive policies in the scenario strategies, thepotential of technical (e.g. prefabricated buildings), economic (e.g. overcoming split
incentives), institutional innovation (e.g. one-stop-shops for targeted advice and support,
decentralized heat networks) and social goals (e.g. affordable housing for low income
families) can be addressed in comprehensive policy packages.

As mentioned above, probably the most ambitious targets of the scenario-based policies
in Germany refer to the heating sector and the retrofit of the existing building stock.
Achieving a doubling or even a tripling of the retrofit rate and a rapidly growing share of
renewable energy for heating systems implies a comprehensive policy mix to drivecomplex system changes, not only in single buildings, but also in neighborhoods anddistricts.

GJETC: Long-term scenario analysis

54

9. Overall conclusions
In this study, a comparative analysis of recent long-term scenarios to reach climateneutrality in Germany by 2045 and Japan by 2050, respectively, was conducted. The
objective was to identify, which strategic technological options are being considered andwhat transferable lessons can be learned. The analysis revealed some similarities in theapproaches as well as divergent assessments (cf. chapter 6). Also, shortcomings ofprevailing scenarios and opportunities to use scenario comparisons as an instrument forsocial learning were identified. Following are some general conclusions which can bederived:9.1 Strategic technological options
For both countries, the scenarios underscored the importance of energy efficiency and of
a forced market introduction of renewable energies. The shift towards a more climateneutral energy mix is supported by expanded electrification of the building and transport
sector and the increased use of ‘green’ or at least low-carbon hydrogen and synthetic
fuels. Finally, both countries also consider technical carbon sinks to compensate residual(“hard to abate”) greenhouse gas emissions. Comparing the strategic technology optionsof German and Japanese scenarios, three important differences can be summarized:(1) The amount of energy reduction
The reduction of primary and final energy by 2045/2050 in German scenarios seems to
be more pronounced than in Japanese scenarios. These differences should be further
explained, e.g., how far this impact is related to more ambitious energy efficiency
improvements or pronounced acceleration of renewable energy sources or different
patterns of structural change. As the UBA GreenSupreme scenario demonstrates, also
within the selected range of German scenarios there are apparent differences
concerning the implementation of the “Energy Efficiency First” principle of the IEA.

GJETC: Long-term scenario analysis

55

(2) Energy mix: Interpretation of the term climate-neutral technology
While Germany aims at a share of renewable energies of almost 100%, including the useof 100% green hydrogen/synfuels by 2045, the renewable energy share in Japanesescenarios varies from only 40 to 100% in Japan (until 2050). Although hydrogen in Japanis also considered as an important strategic pillar of decarbonization, the focus is notnecessarily on green hydrogen, due to a lower share of electricity from renewablesources. Another reason might be that international pipelines for hydrogen supply are
not easily available in Japan. Additionally, almost all of the selected Japanese scenarios
also include nuclear energy and the continued use of fossil energy with CCS technology.
The feasibility of these technologies depends on how much potentials for CCS isavailable, how far renewable energy costs and storage costs will decrease and whethersocial acceptance of nuclear power plants and CCS can be achieved.

(3) Residual emissions and removals:
The German scenarios target at full decarbonization of the energy sector, fewer residual
emissions from the non-energy sectors and relying both on technical and natural sinks.
The majority of Japanese scenarios – due to a larger residual share of fossil fuels – resultin higher remaining greenhouse gas emissions, including those from the energy sector,
and therefore need to strongly rely on CCS, including DACCS (cf Chapters 4, 5, 6).

9.2 Improved scenario approaches
But there are also shortcomings in both countries regarding the methodology and theuse of scenario analyses as well as in policy mixes to effectively guide the fundamental
structural changes and the transition strategies elaborated by the scenarios.
It seems to be worthwhile to address them by future research cooperation on scenarios.
In brief the recommendations can be summarized as follows:

GJETC: Long-term scenario analysis

56▪ Operationalize the principle “Energy Efficiency First” (IEA) and conduct acomprehensive assessment of energy efficiency potentials, costs and co-benefits
in all sectors▪

Prioritize direct electrification (where feasible) instead of gas-based pathways,
due to the higher energy efficiency, by a factor 3 to 5, and hence lower needs toexpand low-carbon power supply▪ Develop integrated energy and material efficiency approaches by combining
climate protection and Circular Economy (CE) strategies▪ Combine technically focused strategies with elements of sufficiency strategies,
including enabling strategies towards sustainable production and consumption▪ Consider barriers and policies to achieve social acceptance, by reflecting also area
restrictions, possible problem shifting (e.g. concerning critical metals) and nature
conservation▪ Integrate socio-economic distributional aspects dealing with just transition,reflecting regional structural change, resilience, citizen participation and citizen
financing▪ Focus on sector coupling and policy integration, e.g. concerning transportation(e.g. e-mobility) and buildings (e.g. heat pumps, district heating/cooling)▪ Continue efforts towards the market introduction of risk-minimizing, low-carbon
technologies to avoid lock-in effects into high-risk technological pathways (e.g.
coal or nuclear energy)

It is evident that the uptake of these recommendations must be considered andevaluated in an international and geostrategic setting. This setting might currently beperceived predominantly as a threat (see outlook), but it would be wise to recognize
the long-term opportunities as well. This general recommendation can besummarized as follows: Assess the opportunities of long-term global dynamics,
innovations and competition of transformative strategies and technologies to carbon
neutrality. Global technical and market developments might change the optimum

GJETC: Long-term scenario analysis

57energy mix in the direction of rapid climate neutrality, more energy security, further
cost degression of low-risk technologies and less resource conflicts on fossil fuels.

9.3 Interlinkages between scenario modelling and policies
In both countries there is a close exchange between the scenario community (e.g., thinktanks) and politics. In the past, e.g. in Germany, political targets regarding GHG emissions
reductions were often justified by scenario-based back-casting approaches. Accordingly,
the GHG reduction targets (2050/2045) defined by the governments appeared more
based on a prevailing perception of the current government what might be “feasible”18
than on the internationally agreed GHG reduction targets that are deemed necessary:
limiting global warming to well below 2°C, if possible to 1.5°C. Thus, in order to develop
comprehensive, independent and research-based climate policy approaches, twoprerequisites need to be taken into account: 1) global necessities and 2) national
possibilities.
9.3.1 Global necessities
IPCC in particular, represents a benchmark for national climate mitigation policies basedon the latest international scientific insights. According to the budget approach, “what isnecessary“ requires a normatively based answer to the question of an appropriate andresponsible national contribution to global climate protection. Thus, the ambition levelof national climate policies and the back-casting target year of decarbonization scenarios
should ideally be in line with global targets and agreements, such as the Paris Agreement
2015.

18

E.g. the Agora study, the only available scenario prospecting climate-neutrality until 2045 at the time of therevision of the German climate protection law in 2021, can be said to have strongly influenced the politicaldecisions.

GJETC: Long-term scenario analysis

58

9.3.2 National possibilities
While taking into account the global necessities, it is also indispensable to consider thenational possibilities of ambitious GHG emissions reduction targets. The question on
national possibilities cannot solely be answered by emphasizing the technologicalfeasibility. Instead, scientific knowledge, political majorities, social acceptance andeconomic interests are key factors that need to be reflected in national climate policies.
To this end, it is of utmost importance that the scenarios provide an analysis of socioeconomic aspects as well. Yet, scenarios also need to consider that policy is able to shapenational possibilities, e.g. by accelerating technology implementation and learning, andby measures to increase acceptance. Only if the important role of science isacknowledged, scenarios can significantly contribute to promising climate policies.
9.3.3 Strengthening the supporting role of science – scenario-based stakeholder
dialogues
The future is uncertain and the uncertainty increases when decisions on decarbonization
strategies for the target year 2045/2050 have to be taken today by majority votes andconsensus. Scenarios can be a powerful instrument of consensus building not only within
the research community or between research and policy, but also related to the interestsof different stakeholders and the broad public.
In Germany, there are some successful processes showing how scenarios contributed toconsensus building on climate protection targets and a consensus-oriented formulationof the climate law in the state of North-Rhine Westfalia (NRW). 19 Furthermore, there are
first positive experiences by establishing citizens assemblies 20 on climate policy inGermany, which were supported by scenario-based research. The integration of civilsociety actors that is enabled in such formats and processes can be evaluated as animportant prerequisite of broader social acceptance.

19e.g. Schepelmann (2018)20

https://www.buergerrat.de/en/news/climate-assembly-in-germany/

GJETC: Long-term scenario analysis

599.3.4 International cooperation
Against the background of international competitiveness, a pivotal role can also be
attributed to international cooperation, e.g. bilaterally between Japan and Germany or ina multinational context like the EU, the G7 or the G20. Synchronous and mutually
reinforcing activities worldwide can help to increase the public support for even morevigorous climate policies at the national level.
Substantial and coordinated steps forward towards climate neutrality in Japan and Germany
could induce important impulses to stimulate modernization, innovation and investment
dynamics worldwide, putting the “well below two degrees” statement of the Parisdeclaration into reach.

9.4 A bright or a frightening outlook?
At the time of writing and finalizing this study (March 2022), the invasion of Ukraine by the
Russian army has already caused endless human suffering and victims. The current
expectation is that the end of the war and its catastrophic consequences are not yet in sight.
It is likely that not only the entire geopolitical structure and the balance of power willchange, but that the global energy system and climate policy will also be massively affected.
So, does this war of aggression change everything for the energy world and the energy
futures outlined above for Germany and Japan? One thing is certain: the perception ofenergy import dependency will change fundamentally, not only in Europe and Germany, but
worldwide. Too much dependence on fossil fuels obviously affects peace and freedom, so it
must be reduced as quickly as possible and, in the future, reduced to zero, not just becauseof climate protection, but for minimizing geostrategic conflicts. Kilowatt-hours saved orgained from sun and wind do not cause or finance wars. For example, Germany's
dependence on Russia for imports of 55% for natural gas, 45% for coal and 34% for oil isextremely dangerous for Germany and indispensable for Russia's military apparatus. But the
15 nuclear power plants and the 55% share of nuclear power in the Ukraine are arecognizable high risk as well, which should be reduced as quickly as possible after the endof the war, hopefully soon. Minimizing all risks connected with the domestic use of energy
sources and the interdependent risks of all imported energy for the exporting and the

GJETC: Long-term scenario analysis

60

importing countries should be taken much more into the research focus of long-term
scenario approaches than in the past.
So, is everything changing? It is possible that climate protection will be pushed into thebackground again by the war. But it is also possible that there will be a growing recognition
that energy efficiency and renewable energies are possible "freedom technologies" (as theGerman Minister of Finance called them), because they reduce conflicts about fossil fuels
and other risky energy technologies, thereby minimizing potentially catastrophic life risks. In
this respect, many options such as energy efficiency and renewable energies will besolutions for both climate action and improving energy security – a win-win situation.
Nevertheless, a general risk check is required for the key energy transition and climate
protection strategies and paths (Fischedick 2022). This also applies to conceivable newimport dependencies in a globalized hydrogen economy or for PV panels.
It seems that bilateral research between Japan and Germany and within the GJETC is
confronted with many new research topics, which should be addressed by intensified
cooperation.

GJETC: Long-term scenario analysis

61

Bibliography
Acatech (2021): Circular Economy Roadmap for Germany. Acatech/Circular Economy Initiative
Deutschland/SYSTEMIQ (Eds.) Update December 2021.
BDI/Boston Consulting Group (2021): Klimapfade 2.0. – Ein Wirtschaftsprogramm für Klima und
Zukunft. URL: https://issuu.com/bdi-berlin/docs/211021_bdi_klimapfade_2.0__gesamtstudie_-_vorabve. (last access, 31.3.2022)
BMWi (Hrsg.) (2021): The Energy of the Future 8th Monitoring Report on the Energy Transition –Reporting Years 2018 and 2019. 296. URL:
https://www.bmwi.de/Redaktion/EN/Publikationen/Energie/the-energy-of-the-future-8thmonitoring-report.pdf?__blob=publicationFile&v=6 (last access, 31.3.2022)
Bundesregierung (2021): Generationenvertrag für das Klima. URL:
https://www.bundesregierung.de/breg-de/themen/klimaschutz/klimaschutzgesetz-20211913672m. (last access, 31.3.2022)
Bundesregierung (2021): Entwurf eines Ersten Gesetzes zur Änderung des BundesKlimaschutzgesetzes. Bearbeitungsstand 11.05.2021.
URL:https://www.bmu.de/fileadmin/Daten_BMU/Download_PDF/Glaeserne_Gesetze/19._L
p/ksg_aendg/Entwurf/ksg_aendg_bf.pdf. (last access, 31.3.2022)
Bundesregierung (2021): Koalitionsvertrag. URL:
https://www.bundesregierung.de/resource/blob/974430/1990812/04221173eef9a6720059c
c353d759a2b/2021-12-10-koav2021-data.pdf?download=1 . (last access, 31.3.2022)
Bundesverfassungsgericht (2021): (1 BvR 2656/18), URL:
https://www.bundesverfassungsgericht.de/SharedDocs/Entscheidungen/DE/2021/03/rs2021
0324_1bvr265618.html;jsessionid=001C1116106F6F190134CB39F2998580.2_cid354. (lastaccess, 31.3.2022)
Bürgerrat (o. J.): Climate Assembly in Germany. URL: https://www.buergerrat.de/en/news/climateassembly-in-germany/. (last access, 31.3.2022)
Deutscher Bundestag (2021): (DS 19/30230), URL:
https://dserver.bundestag.de/btd/19/302/1930230.pdf. (last access, 31.3.2022)
Deloitte Tohmatsu Consulting (2021): Scenario analysis for carbon neutrality society. URL:
https://www.enecho.meti.go.jp/committee/council/basic_policy_subcommittee/2021/044/0
44_008.pdf (last access, 31.3.2022)
Deutsche Energie-Agentur GmbH (Ed.) (2021): „dena-Leitstudie Aufbruch Klimaneutralität“. URL:
https://www.dena.de/fileadmin/dena/Publikationen/PDFs/2021/Abschlussbericht_denaLeitstudie_Aufbruch_Klimaneutralitaet.pdf (last access, 31.3.2022)
Dittrich, M.; Gerhardt, N.; Schoer, K.; Dünnebeil, F.; Becker, S.; Oehsen, A. von; Vogt, R.; Köppen, S.;
Biemann, K.; Böttger, D.; Ewers, B.; Limberger, S.; Frischmuth, F.; Fehrenbach, H. (2020):
Transformationsprozess zum treibhausgasneutralen und ressourcenschonenden Deutschland- GreenSupreme. UBA Climate Change 05/2020. URL:GJETC: Long-term scenario analysis

62https://www.umweltbundesamt.de/publikationen/transformationsprozesstreibhausgasneutrales-ressourcenschonendes-deutschlandgreensupreme#:~:text=Klima%20%7C%20Energie,Transformationsprozess%20zum%20treibhausgasneutralen%20und%20ressourcenschonend
en%20Deutschland%20%2D%20GreenSupreme,%E2%81%A0%20und%20Ressourcennutzung%20untersucht%20wurden. (last access, 31.3.2022)
Energiewirtschaftliches Institut an der Universität zu Köln (EWI) (2021): dena-Leitstudie Aufbruch
Klimaneutralität. Klimaneutralität 2045 - Transformation der Verbrauchssektoren und desEnergiesystems. Herausgegeben von der Deutschen Energie-Agentur GmbH (dena).
European Commission (2021): Communication to the European Parliament, the Council, theEuropean Economic and Social Committee and the Committee of the regions. 'Fit for 55':
delivering the EU's 2030 Climate Target on the way to climate neutrality. URL: https://eurlex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:52021DC0550&from=DE. (last access,31.3.2022)
European Commission (2019): Communication from the commission to the European Parliament, theEuropean Council, the Council, the European Economic and Social Committee and theCommittee of the regions. The European Green Deal. URL:
https://ec.europa.eu/info/sites/default/files/european-green-deal-communication_en.pdf.
(last access, 31.3.2022)
European Commission (2022): Delivering the European Green Deal. URL:
https://ec.europa.eu/info/strategy/priorities-2019-2024/european-green-deal/deliveringeuropean-green-deal_en. (last access, 31.3.2022)
European Commission (2022): European Green Deal : Striving to be the first climate-neutral
continent. URL: https://ec.europa.eu/info/strategy/priorities-2019-2024/european-greendeal_en. (last access, 31.3.2022)
Fath, K. (2017): Technical and economic potential for photovoltaic systems on buildings. Karlsruhe:
KIT. URL: https://www.ksp.kit.edu/site/books/m/10.5445/KSP/1000081498/ (last access,31.3.2022)
Federal Government Germany (2022, März 9): Elimination of EEG levy relieves electricity consumers.
Website of the Federal Government. URL: https://www.bundesregierung.de/bregen/news/renewable-energy-sources-act-levy-abolished-2011854 (last access, 31.3.2022)
Fischedick, Manfred (2022): Energieversorgungsrisiken, Energiepreiskrise, KlimaschutzHerausforderung : Wie sieht die Energieversorgung von morgen aus?
https://wupperinst.org/fa/redaktion/downloads/news/220309_MFStatement_Energieversorgung.pdf (last access, 31.3.2022)
German Environment Agency (UBA) (2013): Potenzial der Windenergie an Land. URL:
https://www.umweltbundesamt.de/sites/default/files/medien/378/publikationen/potenzial_der_windenergie.pdf. (last access, 31.3.2022)

GJETC: Long-term scenario analysis

63German Environment Agency (UBA) (2019): Wege in eine ressourcenschonende
Treibhausgasneutralität. RESCUE-Studie. Dessau-Roßlau. URL:
https://www.umweltbundesamt.de/sites/default/files/medien/376/publikationen/rescue_st
udie_cc_36-2019_wege_in_eine_ressourcenschonende_treibhausgasneutralitaet.pdf. (lastaccess, 31.3.2022)
German Environment Agency (UBA) (2019a): Analyse der kurz- und mittelfristigen Verfügbarkeit von
Flächen für die Windenergienutzung an Land Kurztitel: Flächenanalyse Windenergie an Land
Abschlussbericht, URL:
https://www.umweltbundesamt.de/sites/default/files/medien/376/publikationen/climate_c
hange_38_2019_flaechenanalyse_windenergie_an_land.pdf. (last access, 31.3.2022)
Heinrich Böll Stiftung (2020): A Societal Transformation Scenario for Staying Below 1.5C. URL:
https://www.boell.de/sites/default/files/202012/A%20Societal%20Transformation%20Scenario%20for%20Staying%20Below%201.5C.pdf?
dimension1=division_iup. (last access, 31.3.2022)
IRENA (2019): Future of Solar Photovoltaic: Deployment, investment, technology, grid integrationand socio-economic aspects (A Global Energy Transformation: paper), International
Renewable Energy Agency, Abu Dhabi.
IRENA (2019): Future of wind: Deployment, investment, technology, grid integration and socioeconomic aspects(A Global Energy Transformation paper), International Renewable Energy Agency, Abu Dhabi.
Japanese Forestry agency (2019): Report of study group on forestland development permission forphotovoltaic system [In Japanese].
https://www.rinya.maff.go.jp/j/tisan/tisan/attach/pdf/con_4-11.pdf. (Last access 11 Apr
2020)
Japanese Ministry of Economy Trade and Industry (2021): Generation cost analysis working group,
URL:
https://www.enecho.meti.go.jp/committee/council/basic_policy_subcommittee/index.html#
cost_wg. (last access, 31.3.2022)
Japanese Ministry of Environment (2019): Entrusted Work Concerning the Development andDisclosure of Basic. Zoning Information Concerning Renewable Energies. URL:
https://www.renewable-energy-potential.env.go.jp/RenewableEnergy/report/r01.html. (lastaccess, 31.3.2022)
Obane, H.; Nagai, Y.; Asano, K. (2021): Assessing the potential areas for developing offshore windenergy in Japanese territorial waters considering national zoning and possible social conflicts,
Marine Policy, Vol 129.
Obane, H.; Nagai, Y.; Asano, K. (2020): Assessing land use and potential conflict in solar and onshore
wind energy in Japan, Renewable Energy, Vol160, pp842-851.
Prognos, Öko-Institut, Wuppertal-Institut (2020): Klimaneutrales Deutschland. Studie im Auftrag vonAgora Energiewende, Agora Verkehrswende und Stiftung Klimaneutralität.

GJETC: Long-term scenario analysis

64Prognos, Öko-Institut, Wuppertal-Institut (2021): Klimaneutrales Deutschland 2045. Wie Deutschlandseine Klimaziele schon vor 2050 erreichen kann, Studie im Auftrag von Stiftung
Klimaneutralität, Agora Energiewende und Agora Verkehrswende.
Renewable Energy Institute (2021): Energy mix supporting decarbonization in 2050 in Japan. URL:
https://www.enecho.meti.go.jp/committee/council/basic_policy_subcommittee/2021/044/0
44_006.pdf (last access, 31.3.2022)
Rubin, E. S.; Azevedo, I.M.L.; Jaramillo, P.; Yeh, S. (2015): A review of learning rates for electricity
supply technologies. In: Energy Policy, 86. pp 198-218.
Samadi, S.; Lechtenböhmer, S. (2022): Klimaneutralität bis 2045 – Vergleich der Entwicklungen im
Energiesystem in aktuellen Szenarien für Deutschland. In: Energiewirtschaftliche Tagesfragen
72. Vol. 2022 Issue 3. URL:
https://epub.wupperinst.org/frontdoor/deliver/index/docId/7925/file/7925_Samadi.pdf.
(last access, 31.3.2022)
Schepelmann, P. (2018): Governance of Low-Carbon Energy System Transitions. A case study from
North-Rhine Westphalia, Germany. In: The Governance Brief. ISSUE 32. URL:
https://www.adb.org/sites/default/files/publication/433861/governance-brief-32-lowcarbon-energy-system.pdf (last access, 31.3.2022)
SCI4climate.NRW (2022): Quantitativer Vergleich aktueller Klimaschutzszenarien für Deutschland,
Wuppertal. URL:
https://www.energy4climate.nrw/fileadmin/Service/Publikationen/Ergebnisse_SCI4climate.
NRW/Szenarien/2022/SCI4climate.NRW-Samadi-2022-Vergleich-aktuellerKlimaschutzszenarien-fu__r-Deutschland.pdf (last access, 31.3.2022)
Tao, J. & Gray, M. (2022): Coal-de-sac- The role of advanced coal technologies in decarbonising
Japan’s electricity sector. URL:
https://static1.squarespace.com/static/605b4bcc5526904ff5589918/t/62066db2311106224
09e34eb/1644588483986/TransitionZero_Coal-de-sac_Report_final_full+report.pdf (lastaccess, 31.3.2022)
The Institute of Energy Economics, Japan (IEEJ)(2021): Model analysis for carbon neutrality in 2050.
URL:
https://www.enecho.meti.go.jp/committee/council/basic_policy_subcommittee/2021/044/0
44_009.pdf (last access, 31.3.2022)
The National Institute for Environmental Studies (NIES) (2021): Analysis about scenarios toward
decarbonization by 2050. URL:
https://www.enecho.meti.go.jp/committee/council/basic_policy_subcommittee/2021/044/0
44_005.pdf (last access, 31.3.2022)
The Research Institute of Innovative Technology for the Earth (RITE) (2021): Scenario analysis aboutcarbon neutrality in 2050 (Interim report). URL:
https://www.enecho.meti.go.jp/committee/council/basic_policy_subcommittee/2021/043/043_005.p
df (last access, 31.3.2022)

GJETC: Long-term scenario analysis

65Vartiainen, E.; Masson, G.; Breyer, C.; Moser, D.; Medina, E.R. (2019): “Impact of weighted average
cost of capital, capital expenditure, and other parameters on future utility-scale PV levelised
cost of electricity”, Progress in Photovoltaics,Vol 28 - 6, Special Issue: EU PV SEC.
Wealer, B.; Bauer, S.; Göke, L.; von Hirschhausen, C.; Kemfert, C. (2019): Zu teuer und gefährlich :Atomkraft ist keine Option für eine Klimafreundliche Energieversorgung. In: DIW
Wochenbericht 20/2019.
https://www.diw.de/documents/publikationen/73/diw_01.c.670462.de/19-30.pdf. (lastaccess, 31.3.2022)
Wuppertal Institute (2020) (Ed.): CO2-neutral bis 2035 : Eckpunkte eines deutschen Beitrags zur
Einhaltung der 1,5°C-Grenze; Diskussionsbeitrag für Fridays For Future Deutschland. URL:
https://epub.wupperinst.org/frontdoor/index/index/docId/7606 (last access, 31.3.2022)
Wissenschaftlicher Beirat der Bundesregierung Globale Umweltveränderungen (WBGU) (2009): Der
WBGU-Budgetansatz. Factsheet 3/2009. URL:
www.wbgu.de/fileadmin/user_upload/wbgu/publikationen/factsheets/fs3_2009/wbgu_facts
heet_3.pdf). (last access, 31.3.2022)

GJETC: Long-term scenario analysis

66