The election win could allow the government to more resolutely advance its nuclear energy policy agenda, write Motoko Hasegawa and Evelyn Lee
Japan's snap election on 8 February delivered a landslide victory for the Liberal Democratic Party (LDP), handing prime minister Sanae Takaichi the political strength she needs to accelerate her planned nuclear capacity expansion. This could reduce Japan's reliance on gas-fired generation as a base-load power source, but LNG is likely to remain central to Tokyo's energy security.
The LDP secured 316 seats in the 465-member lower house, giving it a more than two-thirds majority and effectively restoring the legislative power it lost in the 2024 election. Its coalition partner, the Japan Innovation Party, known as Ishin, adds another 36 seats to its majority, meaning Takaichi now has sufficient support to advance her sometimes controversial policies, despite the LDP and Ishin falling short of a majority in the upper house. Under Japan's bicameral system, the upper house has less power than the lower house for legislative and budgetary matters.
Takaichi's energy policies focus on strengthening the country's energy security, centred around a revival of nuclear power. Her administration has sought to accelerate the restart of existing reactors, while also pushing to develop next-generation nuclear technologies,such as fusion power. Next-generation reactors will underpin Japan's long-term energy independence, the prime minister says. The LDP and Ishin hold the view that nuclear development must keep pace with rapidly rising domestic power demand, brought about by a surge in large-scale artificial intelligence data centres. Takaichi hopes to begin installing next-generation reactors near major data centres by the late 2020s, with an eye towards harnessing fusion technology by the mid-2030s.
The LDP had already planned to increase the share of nuclear output in Japan's power mix to 20pc by the 2040-41 fiscal year, even before this month's vote. This target requires the country's operational nuclear fleet to nearly triple to 39.1GW by 2040 from 13.3GW at present. The existing fleet could provide as much as 33.7GW of capacity if all reactors are in operation, but many have not yet been cleared to restart following the 2011 Fukushima-Daiichi disaster. And this goal would still require 5.5GW of new capacity to be built, the Federation of Electric Power Companies said in October. Japan's main opposition party, the Centrist Reform Alliance, also supports restarting reactors but opposes building new ones. It secured only 49 seats in the latest election, reducing its power to block Takaichi's plans.
In the mix
Nuclear power expanded its share of Japan's generation mix at the expense of LNG last year, and may continue to do so this year. The 1.36GW No.6 reactor at Japan's Kashiwazaki-Kariwa plant restarted on 9 February, having been off line since 2012.
The country's nuclear availability averaged 10.8GW in 2025, up from 9.7GW a year earlier, data from power exchange Jepx show. This pushed up Japanese nuclear power generation to 77.8TWh in January-October from 69.9TWh during the same period a year earlier, according to government data. The share of nuclear energy in Japan's power mix grew by one percentage point on the year to 11pc, even as power demand edged higher to 704TWh from 691TWh. By contrast, LNG's share of the power mix fell by two percentage points to 33pc in January-October, while coal maintained a 31pc share. LNG deliveries mirrored this trend, slipping to 66.8mn t last year from 67.1mn t a year earlier, data from analytics firm Vortexa show.
Last year's power mix indicates that an incremental rise in nuclear output displaced LNG rather than coal, given the solid fuel's cost advantage. But Tokyo continues to seek long-term LNG contracts and upstream stakes to ensure stable power supply during its uncertain transition to nuclear energy, and given the still unpredictable pace of power demand growth stemming from data centres.
