On April 1, 2025, the Tokyo Metropolitan Government implemented a new regulation mandating the installation of solar power systems and energy-saving measures in new residential buildings. This regulation is part of the Tokyo Metropolitan Government’s broader initiative to promote green policies, with the goal of achieving a 50% reduction in greenhouse gas emissions by 2030. Here is what you need to know about the regulation and Tokyo’s efforts to promote solar panel recycling.
Regulation Overview
The new regulation requires major housing developers—defined as those with a total annual supply of at least 20,000 square meters of floor space in Tokyo—to install solar panels on newly constructed buildings with a total floor area of less than 2,000 square meters. Existing buildings are not subject to this requirement1.
Costs
According to the Tokyo Metropolitan Government, homeowners can recover solar panel installation costs through energy savings in approximately eight years by utilizing Tokyo’s subsidy program. The metropolitan government estimates that a newly constructed detached house equipped with a 4-kilowatt solar panel system can reduce annual utility expenses by approximately 92,400 yen (equivalent to about 7,700 yen per month)2.
Cost Breakdown:
- Installation cost: 1,170,000 yen
- Government subsidy: 400,000 yen
- Out-of-pocket expense: 770,000 yen
*Estimate based on a household of two or more people in a Tokyo ward (as of August 2024).
Recycling Efforts
The Tokyo Metropolitan Government has been implementing initiatives to promote the recycling of solar panels3.
- In September 2022, the Tokyo Metropolitan Government established the Tokyo Council for the Advanced Recycling of Solar Power Equipment (Japanese: 東京都太陽光発電設備高度循環利用推進協議会), comprising demolition contractors, transportation and collection businesses, recycling operators, and other relevant stakeholders. The council serves as a central hub for developing a comprehensive and efficient recycling system for residential solar panels in Tokyo.
- As part of these efforts, and in collaboration with the council, the Tokyo Metropolitan Government developed the Manual for the Removal and Transportation of Used Residential Solar Panels (Japanese: 使用済住宅用太陽光パネルの取り外し・収集運搬マニュアル) for business operators.
- In fiscal year 2023, the Tokyo Metropolitan Government launched the Residential Solar Panel Recycling Promotion Program (Japanese: 使用済住宅用太陽光パネルリサイクル促進事業). Under this program, the metropolitan government provides partial subsidies to businesses that recycle residential solar panels at designated intermediate industrial waste treatment facilities.
EnerScale Insight
Tokyo’s new solar panel installation regulations are poised to significantly accelerate the adoption of solar energy across the metropolis. These measures may also draw greater attention to the mounting challenge of solar panel waste—prompting stronger efforts toward reuse and recycling. While a subsidy program currently supports solar panel recycling, introducing clear incentives for panel reuse could further advance the circular economy in the solar industry.
Reference
- Tokyo Metropolitan Government Bureau of Environment, “Solar Portal,” [Online]. Available: https://www.kankyo.metro.tokyo.lg.jp/climate/solar_portal ↩︎
- Tokyo Metropolitan Government, “Mandatory installation of solar panels to begin in April 2025,” Koho Tokyo (Tokyo Public Relations), Mar. 2025. [Online]. Available: https://www.koho.metro.tokyo.lg.jp/2025/03/02.html ↩︎
- Tokyo Metropolitan Government Bureau of Environment, “Disposal and recycling of solar panels,” Tokyo Solar Portal, [Online]. Available: https://www.kankyo.metro.tokyo.lg.jp/climate/solar_portal/recycle/ ↩︎
