A series of aerial photos of a mega solar power plant construction site in Kushiro and Kamogawa, Japan.

The reclaimed soil smells like sewage. ……

Three red-crowned cranes, a special protected species, resting in the marsh, one of which is a juvenile born this spring and still sharing the same habitat with its parents. Nearby, dump trucks have been pumping earth and sand into the marsh every day, reclaiming the marshland that used to be a place for people to live (second photo).

Serious trouble is brewing over the construction of a mega solar power plant in Kushiro Marsh (Kushiro City, Hokkaido), which is registered under the Ramsar Convention for the Conservation of Wetlands of International Importance.

In Kushiro City, where conditions are favorable for the installation of photovoltaic power generation facilities, such as the fact that there are many flat areas, there are more than 600 photovoltaic power generation facilities with a capacity of over 10 KW, and the total site area of those under planning alone is equivalent to more than 21 Tokyo Domes. Citizens concerned about environmental destruction have been increasing, and two years ago the city instituted measures to tighten installation standards. However, the plan did not go away, and there were operators who tried to build a large number of new facilities by claiming property rights on private land,” said a reporter from the society section of a national newspaper.

The construction work mentioned at the beginning of this article began in an urbanization control zone about 2 km southwest of the Kushiro Marshland Observation Deck. The area is home to red-crowned cranes and the endangered northern salamander. According to the plan submitted to the city, 6,600 solar panels were to be installed on the 42,000 m2 site, and operation was expected to begin in October of this year (plan delayed).

Kushiro City had asked the operator to confirm that there would be no impact on rare species, but construction began around June of this year without sufficient investigation. When the reporter stood on the site and looked at the reclaimed soil, he saw debris such as pieces of plastic and electric wires. There was also the occasional smell of sewage, perhaps wafting from the soil.

The company involved in this project has notified Kushiro City of its plans for 17 mega solar power plants (two were later abolished), 16 of which are located in the “special conservation zone. The city’s solar regulation ordinance, which went into effect in October, defines these zones as places where rare species of organisms are likely to inhabit. Keisuke Saito, president of the Institute of Birds of Prey Medicine, which is located next to the construction site, is outraged.

The operator must conduct a thorough preliminary survey to ensure that rare species will not be affected,” he said. However, the operator did not conduct a field survey of the red-crowned crane, but only interviewed a single expert. （The survey of the white-tailed sea eagle, which is a rare species, should have been conducted from mid-February to late September, the breeding season, but it was only conducted for three days in October.

The 200-meter difference in elevation is a mountain to be stripped bare.

It is not only wildlife and nature that are threatened by mega solar power plants. Human life is at stake as well.

In Kamogawa City, Chiba Prefecture, plans are underway to install 470,000 solar panels on a vast site of 2.5 million square meters (53 times the size of the Tokyo Dome). Construction began in May of this year, but as shown in the fifth and sixth photos, residents of the village at the foot of the site are concerned that the felling of 370,000 trees could cause a major disaster. Kunie Katsumata, a member of a citizens’ group that opposes the construction project, said, “The solar panels will be laid on the ground.

The plan, which was approved six years ago, does not comply with the new prefectural government standards for disaster prevention, which have been strengthened, and therefore safety cannot be guaranteed. With the number of disasters on the rise, including guerrilla rains, there is a risk of mountain collapses and river flooding if the embankment construction is pushed too hard.

The prefectural government has issued administrative guidance to operators in 58 locations and asked them to review their plans to ensure safety, but it remains unclear to what extent this will be done. What can be done to prevent the mega solar power plant problems that are occurring across Japan? Hidetoshi Yamashita, an associate professor at Hitotsubashi University and an expert on renewable energy policy, points this out.

When the government launched the feed-in tariff system (a system under which electric power companies promise to purchase electricity generated from renewable energy sources at a certain price), it failed to establish regulations that would allow it to control the siting of such plants, which has led to the mega-solar problem. In order to prevent problems, the government needs to strengthen regulations, establish local ordinances, demarcate installation zones, and conduct thorough investigations of operators.

The government has established a liaison council of related ministries and agencies to study how to coexist with local communities and strengthen discipline. The pros and cons of mega solar power plants are being questioned.

November 7, 2025 issue