Japan’s energy sector is undergoing a significant transformation, with the share of fossil fuels in its power supply dropping to a record low in the first half of 2025. As reported by clean energy think tank Ember and cited by journalist Gavin Maguire, this shift is largely fueled by an increase in nuclear and solar energy production.
For the first time, the portion of Japan’s utility-scale electricity generated from fossil fuels fell below 60% between January and June 2025. This marks a notable change for a nation that has historically depended on imports of liquefied natural gas (LNG), crude oil, and coal to meet its energy needs. At the same time, the contribution of low-carbon electricity sources, such as nuclear and renewables, reached its highest level in over a decade.
Renewed Focus on Nuclear Energy
Following the Fukushima disaster in 2011, many of Japan’s nuclear reactors were taken offline for safety inspections. However, the country is gradually reactivating some of these capacities as part of its broader decarbonization strategy. Currently, nuclear energy represents less than 10% of Japan’s electricity supply, but the government aims to increase this figure to 20% by 2040.
Before the Fukushima incident, nuclear energy accounted for approximately 30% of Japan’s power mix. The resurgence of this energy source, along with a significant rise in solar power generation, has contributed to the decline of fossil fuels in the energy landscape. Estimates indicate that solar power generation has increased by a remarkable 25 times since 2010.
Growth of Renewable Energy Sources
In addition to solar energy, other renewable sources have also seen substantial growth. Over the past fifteen years, electricity production from bioenergy power plants has more than doubled, while wind farm output has also significantly increased. Japan is actively working to develop its offshore wind capacity, aiming for a total of 10 GW of offshore projects by 2030 and between 30 GW and 45 GW by 2040.
Despite these ambitious targets, the offshore wind sector faces challenges, including rising costs and supply chain delays. The government has conducted three auctions to award offshore wind capacity, but major developers are reassessing their involvement amid global market pressures.
Japan’s strategy reflects a broader commitment to reducing carbon emissions and transitioning to a more sustainable energy model. As the nation continues to navigate its energy future, the shift away from fossil fuels represents a crucial step in addressing the challenges of climate change and energy security.
