Renewable Pathways to Climate-neutral JapanReaching Zero Emissions by 2050 in the Energy System

9 March 2021

in Japanese

Japan has pledged climate-neutrality by 2050. Now, on the tenth anniversary of the Fukushima accident, a new report by Renewable Energy Institute (REI), Agora Energiewende, and LUT University finds that a zero-carbon energy supply based solely on renewables would be affordable in Japan (updated June 2021).  

LUT University performed a first-of-its-kind modelling of the Japanese energy system across sectors and regions and at a one-hour time resolution. “With such a model, we were able to capture precisely all the flexibility requirements and technical options to facilitate the integration of very high shares of variable renewables in Japan,” explains LUT professor Christian Breyer.

Entitled “Renewable Pathways to Climate-neutral Japan: Reaching Zero Emissions by 2050 in the Energy System”, the study sets forth a three-step roadmap for renewables deployment and electrification.
First, greenhouse gas emissions would fall by 45% by 2030 (relative to 2010) based largely on at least a 40% share of renewables in the power sector. The rollout of renewable electricity would be based on a comprehensive policy package to drive investments in new renewables. This renewable power would then replace coal power, which would be reduced to zero by 2030 based on a phaseout plan. 

Second, emissions must decline by at least 90% by 2045 (relative to 2010). In this phase, renewables continue to grow, and electrification enters the foreground. The heat sector switches to electricity by means of heat pumps, whereas electric vehicles would become the norm on roads. At the same time, ambitious building standards and stringer regulations for vehicles would ensure efficiency gains.

Finally, green synthetic fuels eliminate residual emissions by 2050, mostly from high-temperature heat generation in industry. Not all of the processes based on fossil fuels today will, however, simply switch to green hydrogen; rather, electrification will be the preferred option economically in most cases, with hydrogen filling in the gaps. Direct electrification should therefore be prioritized wherever possible in transportation, space heating and low and mid-temperature heat in industry already today and explored for high-temperature heat.
Because green hydrogen is made from renewable electricity, producing large amounts of it domestically would significantly increase the amount of wind turbines and solar panels that need to be installed in the country. The roadmap thus foresees some imports of green hydrogen.

One option currently debated in Japan is nuclear power. The study finds, however, that nuclear is not necessary to achieve the long-term decarbonization target at a low cost. On the contrary, renewables will increasingly be less expensive than new nuclear and even lifetime extensions starting as soon as 2025. “Accelerating the deployment of renewables is essential to achieving climate neutrality by 2050” explains REI’s Senior Manager Yuko Nishida. “Reaching 100% renewables in 2050 is not only a vision for Japan, it is economically and technically feasible.”

Of course, these steps overlap; industry facilities, for instance, are built for decades, so any new production plants built before 2030 would at least need to be retrofittable for eventual zero emissions. Japan must therefore act now. “As a global technological leader, Japan can help pave the way towards a renewables-based energy system,” says Agora’s Director Patrick Graichen. “And as an economic powerhouse, Japan must be a leader in the global push for climate neutrality.”

The upcoming discussions on the 6th Strategic Energy Plan and concrete regulatory measures such as an effective carbon pricing mechanism will be crucial to determine how Japan can achieve interim 2030 targets and climate neutrality by 2050. Japan must kick-start enhanced climate action as soon as possible by increasing its interim sectoral targets to reach 45% lower greenhouse gas emissions and at least 40% renewables in power generation by 2030. In particular, Japan’s Green Growth strategy should include a comprehensive program to boost economic growth while moving the economy towards climate neutrality based on renewables deployment.


About Agora Energiewende
Agora Energiewende is an independent think-tank and policy laboratory.  To ensure the success of the Energiewende, it develops scientifically sound, politically feasible approaches. Along with experts from public policy, civil society, business and academia, it develops a common understanding of the energy transition, its challenges and courses of action. Agora Energiewende is a joint initiative of the Mercator Foundation and the European Climate Foundation.

About LUT
Clean energy, water and air are life-giving resources for which LUT University seeks new solutions with expertise in technology and business. LUT helps society and businesses in their sustainable renewal.
LUT's campuses are located in Lappeenranta and Lahti, Finland. The international science community is comprised of 6,500 students and experts engaged in scientific research and academic education.


External Links

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  • 自然エネルギー協議会
  • 指定都市 自然エネルギー協議会
  • irelp
  • 全球能源互联网发展合作组织

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