Together with Sinopec, China's two other major oil and gas companies, China National Petroleum Corp and China National Offshore Oil Corp, or CNOOC, are also stepping up efforts to transform themselves into greener energy businesses.

China National Petroleum Corp, the country's largest oil and gas company, has intensified its solar, wind and hydrogen business. It said it will have four refueling stations to supply 816 hydrogen-powered vehicles for the upcoming Winter Olympics.

CNOOC, the nation's leading offshore oil and gas driller, aims to place 5 percent to 10 percent of its total investment in solar and wind energy each year to ensure these sectors achieve major breakthroughs from 2021 to 2025.

Wang Dongjin, chairman of CNOOC, said that the offshore wind sector aligns with the company's overall business. CNOOC can apply its resources in offshore engineering and experience in such operations, and the company plans to intensify its new energy business by focusing on offshore wind power.

CNOOC's first wind turbines, located off the coast of Jiangsu, started production by the end of last year, with a total installed capacity of 300 megawatts.