A decline in the cost of solar, wind and battery storage would help Japan achieve this feat, the study said.
Japan’s power grid, with extra battery storage and inter-regional transmission lines, could remain reliable without coal generation or new gas-fired power plants, it added.
The Group of Seven countries, including Japan, committed last year to largely decarbonise their power sectors by 2035 to tackle climate change. However, Tokyo has yet to map out a clear path for the goal.
Resource-poor Japan faces a significant energy security risk as it imports nearly all of the fuel used in its power sector.
Clean electricity – which includes generation from solar, wind, hydropower, biomass, hydrogen and even nuclear sources – currently accounts for 24% of Japan’s total energy.
Clear policies needed
Raising the share of clean energy to 90% would cut Japan’s electricity costs by 6%, the study found. It would also cut power sector emissions by 92% from 2020 levels, it said.
But Japan needs clear policies, such as setting medium-term targets beyond 2030 and corresponding renewable deployment goals, to take advantage of the economic, environmental, and energy security benefits, it added.
The study is based on modelling using the latest cost data on renewables and batteries, and is consistent with Japan’s 2030 policy goals and the G7 commitment.
Japan aims to cut greenhouse gas emissions by 46% by 2030 versus 2013 levels. It aims to do so by boosting renewable energy in its electricity mix to 36%-38%, double 2019’s levels, and nuclear power to 20%-22% from 2019’s 6%.
The world’s fifth-biggest emitter also aims to achieve carbon neutrality by 2050.
Under the scenario with the least-cost combination of generation, storage and transmission, renewable power, including floating offshore wind, totals 70% of the electricity mix by 2035.
Nuclear and gas-fired power will account for 20% and 10%, respectively, while existing coal power plants are phased out, the study said.
- Reuters, with additional editing by Vishakha Saxena