Shota Furuya

Pieces日本語版

Don't large solar farms destroy forests and landscapes?

Since the late 2010s, disputes over the construction of large solar farms have been reported across Japan: Hokuto in Yamanashi, Ito in Shizuoka, Bansan in Sendai, Kirigamine in Suwa, Tsuno in Miyazaki — the list of place names runs on. When a debris flow struck Atami in July 2021, the direct cause was identified as illegal fill upslope, but the case was discussed alongside a nearby solar development, and many people were left with a firm association between renewables and the destruction of forests.

Seeing all this, it is a natural reaction to feel that clearing forest to lay out panels defeats the purpose of decarbonisation, and that the loss of scenery and the risk of landslides are too high a price. This piece sets out what the data actually says, how the rules have changed, and the international design principles for reconciling the two. To anticipate the conclusion: the problems are real, but they are not limits of renewable energy itself. They are the immaturity of siting governance, and the way out is already visible.

Solar and forests, in numbers

Start with the scale. Japan’s cumulative solar capacity reached about 91 GW by the end of FY2024 (Agency for Natural Resources and Energy). Of that, utility and commercial solar (10 kW and above, including large solar farms) accounts for roughly 55 GW. Ground-mounted solar needs about 1–2 ha per MW, so even if all 55 GW were on the ground, the area occupied would be at most around 110,000 ha.

Japan’s land area is about 37.8 million ha, of which about 25 million ha — some 66% — is forest (Forestry Agency). Even if half the land under large solar farms had been converted forest, that is about 0.2% of all forest. In fact the Forestry Agency’s figures put cumulative permitted forest development for solar from FY2012 to FY2022 at about 7,400 ha, which is orders of magnitude smaller than annual forest losses from windthrow, fire and pests, or than the area of postwar plantation being harvested.

At the macro level, in other words, there is no evidence that renewables are consuming Japan’s forests. But that is an average, and the regional variation is enormous. In the steep interior of the Pacific side, and on the plateaus opened up by resort development, projects have concentrated in ways that affect residents’ surroundings, water catchments and landslide risk directly. The problem is not the total but the skew in location, scale and process.

Why the “wrong places” got built on

Understanding this means understanding the design weaknesses of the old feed-in tariff. Introduced in 2012, the FIT was a globally successful policy for accelerating deployment in volume. But it asked nothing about where generation was built, which made cheap hillside and scrub land the economically rational choice. Because early tariffs were set high — ¥40/kWh in FY2012 — a large number of projects took the certification and delayed construction, waiting for land prices to fall before breaking ground.

Beyond that, social acceptance and landscape governance were left almost entirely to municipalities. Large solar was only brought under the Environmental Impact Assessment Act in April 2020 (mandatory above 40 MW, second-class from 30 to 40 MW), so many earlier projects carried no statutory assessment obligation. Forest development permits existed under Article 10-2 of the Forest Act, but splitting sites into parcels of a hectare or less to avoid the permit process was not uncommon, and that fed local mistrust.

Past cases, then, are better understood not as problems of technology or of renewables as such, but as the result of land-use governance failing to keep pace with the strength of the economic incentive.

How the rules have changed

The regulatory environment has changed a great deal in a decade. The 2017 FIT amendment introduced expiry rules for deemed certifications; 2020 brought the revised Act on Promotion of Global Warming Countermeasures and the revised assessment law into force; 2022 began the parallel running of FIT and FIP. Then in 2023 the renewable energy special measures act was amended to make permits under related laws a precondition for METI’s project certification where forest development is involved, with FIT/FIP certification revoked for breaches. That effectively ended the old development model of securing an offtake contract first and falling out with the community later: agreement at the siting stage is now built into the economics.

The revised warming countermeasures act also lets municipalities designate promotion zones. Projects inside a zone receive certain procedural allowances, while designating the zone requires discussion in a council of residents, experts, developers and the municipality. As institutional change in Japan, that is a step forward. Only a few dozen municipalities had designated zones by the end of FY2024, and few have attempted zoning across a whole municipality, so contradictions arise in practice. Even so, these rules are the footing for moving the relationship between renewables and communities from confrontation towards joint design.

On disaster prevention, the fill regulation act that took effect in 2023 made earthworks — including those for solar farms — subject to permits by regulated area, tightening the constraint on inappropriate modification of land. It codifies the lesson of the Atami debris flow and applies to all earthworks, not only renewable projects.

The places to build are roofs and degraded land, not mountains

Mountain forest is not where solar should be built in Japan in the first place. Estimates by the energy agency and the environment ministry put rooftop potential alone, residential and non-residential, at about 280 GW, and at over 400 GW including car parks, agrivoltaics and floating solar on reservoirs. That covers the 260–370 GW of solar considered necessary for carbon neutrality by 2050 without leaning heavily on ground-mounted systems.

Two things deserve particular attention: agrivoltaics and the use of abandoned farmland. Japan had about 420,000 ha of abandoned farmland in 2020 (Ministry of Agriculture, Forestry and Fisheries), and using even part of it leaves room for tens of gigawatts. In Sosa in Chiba and the Hamadori area of Fukushima, agrivoltaic projects run by local farmers with citizen investment, combining farm income with energy revenue, are becoming established.

It is easy to overlook in arguments about scenery, but it is worth stating plainly that rooftop solar has essentially no landscape impact. Japan is densely populated, so its total roof area is not inferior to that of the major European countries. The economics work too: against a residential FIT price of ¥16/kWh in FY2024, retail electricity is around ¥30/kWh, so a system built for self-consumption pays back in about ten years. Tokyo’s requirement for solar on new detached houses, in force from April 2025, is a policy judgement grounded in that shift.

International principles for building with nature

Reconciling renewables with landscapes and ecosystems is an active international discussion. IRENA’s Nature-Positive Energy principles, published in 2025, organise the idea of nature-positive energy into six: (1) design a net gain for ecosystems into the siting stage, (2) draw multiple functions from land through co-use, (3) strengthen conservation and restoration, (4) monitor and manage adaptively, (5) extend the life of installations, and (6) institutionalise local participation.

The key method is the mitigation hierarchy: avoid, then minimise, then restore, then offset. Avoid primary forest and ecologically valuable areas from the outset, minimise what is unavoidable, restore what is altered, and offset what remains. The sequence is standard in the safeguards of international financial institutions, and it is becoming the de facto standard in renewable siting in Japan too.

On landscape, Europe works with the concept of landscape governance: treating a landscape not as a view but as a social construct bound up with the lives, culture and memory of the people there, and deciding its future with them from the planning stage. Research on the Munga–Hamra power line dispute in Sweden (Peacock & Devine-Wright 2026) shows the value of participatory GIS in discussing place attachment and renewable siting together.

Japan has its own models — Iida in Nagano, for instance, where agreement with local stakeholders and citizen investment are combined so that siting, scale and the distribution of benefits are designed as one. Opposition to large solar farms is rarely opposition to renewable energy; it is resistance to decisions being made about one’s own place, elsewhere and out of sight. Empirical work in several countries confirms that arrangements for local participation and local returns improve social acceptance substantially (Wüstenhagen et al. 2007; Knauf & Wüstenhagen 2022).

Summary

  • Forest loss to large solar farms amounts to something like 0.2% of Japan’s forest, so the claim that renewables are destroying the country’s forests is not supported by the data. What is true is that concentration in particular areas has produced serious conflict.
  • The problems came not from technology but from land-use governance failing to keep pace with the FIT’s economic incentive.
  • The 2020 assessment law revision, the 2023 amendments to the renewables act and the fill regulation act, and the promotion-zone system have strengthened siting governance considerably.
  • Japan’s solar potential across roofs, car parks, farmland and water is on the order of 400 GW, so decarbonisation is achievable without clearing mountains.
  • Nature-positive energy principles, the mitigation hierarchy and participatory landscape governance make it possible to have both nature and renewables.
  • Opposition is not a rejection of renewables but resistance to exclusion from local decisions, and the answer lies in designing participation and returns into projects.

Sources

← Back to list