By Anders Lorenzen

Last week, regulators in the local assembly of Tokyo, the capital of Japan, ruled that all new homes constructed by large-scale homebuilders after April 2025 must install solar panels to cut emissions.

This mandate will be the first of its kind for a Japanese municipality and will require about 50 major builders to equip homes of up to 2,000 square metres (m2) with renewable energy technologies, mainly solar power.

Poor solar uptake

The capital’s Governor, Yuriko Koike, had noted that by the prior week, only 4% of buildings in the city which could have installed solar, actually had done so.  

By 2030 the Tokyo Metropolitan Government has set targets that aim to halve greenhouse gas (GHG) emissions compared to 2000 levels.

Japan is the fifth-largest CO2 emitter in the world and has committed to being carbon-neutral by 2050. But the country switched off most of its nuclear generators following the 2011 Fukushima disaster. Therefore its coal consumption increased, making that target much harder to achieve. In Europe, Germany is facing similar challenges, as it decommissioned its nuclear fleet after Fukushima and as a result, has increased coal burning and so also its emissions.

Risako Narikiyo, a member of Koike’s regional party Tomin First no Kai said on the assembly floor: “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.”

In recent years Japan has been ravaged by a series of extreme weather events linked to the burning of fossil fuels.