J-Power, the country's biggest coal-fired power generator, also aims to be carbon neutral by 2050, in line with the Japanese government's pledge, by expanding the use of hydrogen.

While suspending operation of older thermal power stations by 2030, the company will expand its renewable energy capacity by 1 gigawatt (GW) by March 2026 from 9 GW as of March 2018 which is mostly comprised of hydro power.

To boost carbon-free power generation capacity, J-Power also aims to start the Oma nuclear power plant, which is under construction, in the financial year starting April 2028, Hitoshi Kanno, J-Power's executive managing officer, told a news conference.

The company plans to cut emissions by 19 million tonnes by 2030 from average annual emissions during 2017-2019 financial years of 46.33 million tonnes, a company spokesman said.

The planned shutdown of old power plants would reduce its annual profit by about 10 billion yen ($94 million), but the company plans to offset the loss by increasing renewable power and overseas businesses, Kanno said.

($1 = 106.3600 yen)

(Reporting by Yuka Obayashi. Editing by Jane Merriman)