Mega Solar Power Projects: Strengthen Regulations to Suit Local Circumstances

Editorial

16:23 JST, January 10, 2026

Solar power generation is a pillar of renewable energy for the realization of a decarbonized society. With suitable generation sites for the energy source becoming scarcer in Japan, efforts must be made to utilize solar power in ways adapted to local circumstances.

In December last year, the government compiled a package of measures to strengthen regulations for mega solar power projects.

Key points of the measures include abolishing government support for new projects, expanding the scope of projects subject to environmental impact assessments and strengthening oversight of operators. The package encompasses about 20 measures, including a review of the application of the Landscape Law.

This marks a major shift in the nation’s solar power policy as promoted by the government after the Great East Japan Earthquake.

The spread of solar power has been remarkable. Solar power accounted for only 0.3% of the nation’s energy mix in fiscal 2010, but its share rose to 9.8% by fiscal 2023.

Japan’s cumulative installed solar capacity ranks among the world’s highest, at more than double the level of other major countries per unit of flat land area. However, as sites suitable for solar power generation have become scarcer, notable distortions have emerged. It can be said that Japan has reached a stage where regulations need to be strengthened.

Opposition movements have arisen near the national park around Hokkaido’s Kushiro Wetlands, voicing concerns about impacts on the ecosystems of rare bird species. In Kamogawa, Chiba Prefecture, there have been concerns over possible landslides due to mountain forest development related to solar power generation, which involves land area equivalent to 30 Tokyo Domes.

Maintaining solar power as a vital energy source will become difficult unless the government faces local residents’ distrust of such projects. It is necessary to curb reckless development.

The driving force behind the spread of solar power is a system under which electricity generated from renewable sources is purchased with a fixed premium added to the market prices.

This system was launched in 2012, but support for new mega solar projects will end from fiscal 2027, according to the package. With the aim of curbing disorderly expansion, this move is reasonable.

Under its basic energy plan, the government aims to increase solar power’s share to 23%-29% by fiscal 2040. Wisdom must be exercised to find ways to spread the use of solar power even in areas where suitable sites are limited.

There remains ample space that could be used for solar power generation, such as rooftops of high-rise buildings and factories as well as the tops of agricultural greenhouses.

Next-generation perovskite solar cells, which are lightweight and bendable, are effective, as they can be installed at varied locations more flexibly. It is hoped that the government will support technological improvements in manufacturing such solar cells to prevent Japan from lagging behind China.

A massive number of solar panels are expected to be disposed of starting in the second half of the 2030s when they reach the end of their service life. The government also should advance efforts to establish a legal framework that will mandate recycling solar panels.

Given the increasing constraints on solar power generation, it is important to focus on developing diverse renewable energy technologies, not limited to offshore wind and geothermal.

(From The Yomiuri Shimbun, Jan. 10, 2026)