A consortium of 12 Japanese companies said Tuesday that it has invested in Commonwealth Fusion Systems, a U.S. fusion energy startup.

The consortium aims to commercialize nuclear fusion power generation in Japan at an early date by acquiring technical knowledge through the investment. The group¡¯s ownership ratio in Commonwealth Fusion Systems was not disclosed.

The 12 companies include trading companies Mitsubishi and Mitsui & Co., telecommunications company NTT, Kansai Electric Power, shipping company Mitsui O.S.K. Lines and Jera, the largest power generation company in Japan.

Founded in 2018, Commonwealth Fusion Systems, a startup from the Massachusetts Institute of Technology, aims to start operations of a demonstration reactor for nuclear fusion in 2027 and put a commercial power plant into operation in the early 2030s.

Nuclear fusion is drawing attention as it generates a significant amount of energy without emitting carbon dioxide.