According to Reuters, officials require some 50 major home builders to equip new buildings with as much as 2.000 square meters worth of renewable power sources.

Tokyo Governor Yuriko Koike recently said that out of all residential buildings that can have solar panels installed on them, only 4% have renewable power sources implemented.

The move to accelerate the development of renewables comes as Tokyo authorities plan to halve their emissions by 2030 compared to 2000 levels.

Being the world's fifth carbon-emitter, Japan promised to achieve carbon neutrality by 2050, although this task could be difficult, as the country has been relying more heavily on coal power ever since the Fukushima disaster in 2011, when most of the nuclear reactors were shut down.

Risako Narikiyo, a member of Koike's regional party Tomin First no Kai, said that "in addition to the existing global climate crisis, we face an energy crisis with a prolonged Russia-Ukraine war. There is no time to waste."