Power sector in 2030
Japan’s power system is dominated by coal (33%) and natural gas (39%) with 19% coming from renewables and another 9% from nuclear. Nuclear energy provided a quarter of power until the Fukushima nuclear accident in 2011. It is slowly increasing again after the 2014 total shutdown, but it is unclear whether it will ever fully regain its former role. For much of the last three decades renewable share in power generation remained around 10%, and this was almost entirely due to hydroelectricity. However, beginning in 2012, the country saw an accelerated uptake of solar power.,
Paris Agreement compatible pathways show a phase-out of unabated coal by around 2030 and unabated gas between 2038-40. This would primarily be achieved through a significant scale-up of renewable power, which could supply 51-82% of Japan’s power by 2030, and close to 100% in 2050. A share of at least 60% would need to be achieved in order to avoid reliance on nuclear energy nor fossil fuels with CCS.
Japan faces unique challenges in decarbonising its power sector. Historically, the country has opted for nuclear power and energy efficiency measures as a means of meeting increasing demand and maintain security of supply. More recently, demand trends have shifted significantly and, on the supply side, nuclear power’s share in generation dropped after the 2011 Fukushima accident.
Issues with security of supply remain, given the country’s isolated location. While the country has limited potential for solar and onshore wind, offshore wind could provide significant power generating capacity. The government has identified offshore wind as a key area of focus in its long-term energy planning. At the same time, Japan also sees nuclear and fossil CCS as important contributors to a future power grid.,
Towards a fully decarbonised power sector
Under 1.5°C compatible pathways, Japan’s power sector achieves carbon neutrality between 2040 and 2043 by phasing out unabated coal from around 2030 and unabated gas between 2038 and 2040.
Nearly all pathways retain nuclear power in the generation mix.
Some pathways assume a certain level of reliance on carbon dioxide removal. In these pathways fossil fuel generation with CCS commences from the 2030s and accounts for 29-32% of total generation in 2050. In addition to CCS, residual emissions under these pathways are abated with negative emissions technologies, also starting in the 2030s, i.e., bioenergy with CCS which, by 2050, accounts for 1.6-3.2% of total power generation. CCS has yet to been proven an effective means of emissions reduction at scale. Relying on this technology is thus risky.
Japan could achieve a fully decarbonised power system based on renewable energy and storage technologies. The 100% renewable energy pathway modelled here has non-bio renewables share in power generation increasing from 16% (2019 levels) to 81% by 2030 and nearly 100% by 2050.
In addition to energy efficiency measures, technologies most readily available to Japan to facilitate this transition are solar PV on buildings and offshore wind, paired with geothermal and hydropower.