Research Paper

Feasibility and Policy Challenges for Rooftop Solar PV During Japan's Energy Policy Transition

Author	Hideaki Obane
Summary	Japan has experienced rapid growth in solar photovoltaic (PV) deployment since the introduction of the Feed-in Tariff (FIT) scheme in 2012. As of December 2025, the cumulative installed capacity approved under the FIT scheme had reached ...
Outline	Japan’s solar PV policy is shifting from large ground-mounted systems toward rooftop installations to address environmental concerns. This study assesses the feasibility of rooftop solar PV for non-residential and public buildings by examining technical potential and cost structures. Although rooftop PV has a technical potential of 137 GW, only 13.1 GW is associated with buildings covered by the revised Energy Conservation Act, limiting policy effectiveness. Furthermore, installation costs remain the primary barrier to economic viability, particularly for small buildings. The findings suggest that future support schemes should prioritize reducing installation costs and expanding deployment beyond regulated buildings.
Keyword	Solar PV, Energy Policy, Renewable Energy, GIS, Cost analysis, Potential
Media	ＨＰ (7/10/2026)
Report PDF	https://test-eneken.mvmt.jp/data/13383.pdf