The Tokyo municipality is working on new regulations to make it mandatory for new homes with a total roof area of more than 20 square meters and for buildings with a roof area of less than 2,000 square meters to install solar energy.

The Tokyo Metropolitan Government and the Japan Photovoltaic Electricity Association (JPEA) are jointly developing new regulations to support the development of rooftop photovoltaics throughout the Japanese capital.

The authorities plan to introduce new mandatory PV requirements for new buildings and dwellings from 2025. The city government first announced plans for a mandatory solar requirement in early September and it is still under discussion in the Tokyo Metropolitan Assembly.

The new rules, if approved, could apply to new homes with a roof area of more than 20 square meters and buildings with a total roof area of less than 2,000 square meters, and could also require businesses to install solar arrays on 30 percent of their roof area, and some parts of the city will also May face the requirement of 85% PV coverage on all roofs.

The new rules, which will require developers and installers to use panels from manufacturers that respect human rights, appear to mean that solar modules made with polysilicon from Xinjiang, China, may not be allowed due to alleged use of forced labour.