Japan stands as the fifth largest carbon emitter in the world. The country has devoted itself to executing carbon neutrality by 2050.

Japan’s capital’s local council said on Thursday that all new homes built in Tokyo by major home builders after April 2025 will have to install solar panels to cut homes’ carbon footprint.

According to the news agency Reuters, the new regulations on new homes will require around 50 major builders to equip homes up to 2,000 square meters (21,500 sq ft) with renewable energy (mainly solar panels).

Tokyo Governor Yuriko Koike last week noted that only 4% of the city’s buildings that can install solar panels currently have them installed. However, the Tokyo Metropolitan Government aims to halve greenhouse gas emissions from 2000 levels by 2030.

Risako Narikiyo, a member of Koike’s regional party Tomin First no Kai said, “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.”

Meanwhile, researchers in California also launched a solar space program after receiving a $100 million grant in 2013, and groups in countries like Japan, Russia, and India are also exploring the possibility.