Japan Targets Rooftop Solar Growth with Mandatory Space Reporting Plan

Tokyo, April 3, 2025 — Japan’s Ministry of Economy, Trade and Industry (METI) has introduced a policy proposal that would require businesses to regularly report rooftop space available for solar panel installation. The measure is aimed at accelerating rooftop solar deployment as part of Japan’s broader renewable energy strategy.

Under the proposal, designated high-energy-consuming businesses would need to report key rooftop data, including total area, structural load capacity, seismic standards, and the portion already equipped with solar systems. The rule would apply to buildings with rooftop areas of 1,000 square meters or more.

The system is set to take effect from fiscal year 2027, while businesses will also be required to include qualitative rooftop solar goals in their mid- to long-term energy plans starting FY2026.

METI also signaled support for next-generation technologies, including lightweight perovskite solar panels, by linking rooftop load capacity data to subsidy eligibility.

Rooftop solar remains a focus in Japan’s 7th Basic Energy Plan, and over 30% of companies have already expressed plans to adopt solar power in their energy strategies.