Japan Sets 2040 Energy Targets as Nuclear Queue Lengthens and Biomass Subsidies Disappear
Tokyo's plans for 20% nuclear power and 6% biomass by 2040 rest on regulatory and commercial foundations that are visibly weakening.
Molten salt reactors cleared a major U.S. regulatory hurdle on Sunday (2026-07-26), oilprice.com reported, advancing a clean baseload technology that developers and policymakers across Asia are watching closely. Japan's energy ministry has its own portfolio of ambitious 2040 targets. The policy ambition is rising. The commercial and regulatory infrastructure needed to meet it has been weakening.5
Japan's latest Basic Energy Plan, as reported by the Economist in May 2026, targets nuclear power at 20% of the electricity mix by 2040, up from under 10% last year.1 Reaching that share requires nearly all 21 reactors currently eligible for restart to be operating within that period, the Economist noted, making the regulatory approval queue the effective bottleneck on the entire plan.
The queue offers little comfort. Japan has 15 operational reactors, the Economist reported in May 2026; three more have received safety clearances but remain offline, while 18 others are still working through the regulatory process.1 Industry ministry plans published in mid-2026 envision two to five new reactors built by the 2040s and up to 14 replacements by 2050, PNA reported.4 No reactor has broken ground in Japan since before Fukushima. The 2040 timeline leaves limited room for the multi-decade construction cycles that define the sector.
The three units that have cleared safety reviews but remain idle are the most immediate test. If regulators and operators cannot move those units into commercial service, the prospect of processing 18 more approvals and initiating new builds simultaneously becomes harder to take at face value.
Beneath the nuclear headline sits a waste problem with no current resolution. Japan has not secured a long-term storage site for its nuclear waste, a constraint that has persisted for years, japan-nrg.com reported in May 2026.2 Expanding the fleet without resolving storage requires either a political decision that has so far proved elusive or a technical arrangement that has not emerged.
Biomass is facing its own inflection. The fuel accounted for 4.1% of Japan's energy mix in 2023, with METI's Basic Energy Plan targeting 6% by 2040, japan-nrg.com reported in June 2026.3 METI abolished feed-in tariff support for woody biomass assets above 10 MW from April 2026, removing the subsidy that made large-scale projects financeable. Many existing plants are midway through their FIT support periods. Operators approaching the end of those periods face a revenue model that no longer functions, with no replacement framework in place.3
Renewables face a third set of barriers. Wind turbines in Japan must meet earthquake-resistance standards equivalent to those for tall residential buildings, the Economist reported, raising development costs significantly. Land-use regulation blocks solar deployment on abandoned farmland. Transmission infrastructure is too weak to carry renewable output to where it is consumed, the Economist reported.1 Expansion has slowed rather than accelerated.
The JKM Asian LNG benchmark stood at $22.00/MMBtu on Monday morning (2026-07-27). Japan pays that price at scale because its domestic generation build-out has not reduced import dependence. Each year that eligible reactors sit idle, or each biomass plant that closes after FIT support ends, extends that exposure.
How quickly the nuclear regulator processes the 18 pending approvals, combined with the commercial fate of the three already-cleared but idle units, will be more revealing about Japan's energy delivery record than any revision to the 2040 plan.1,4