Marubeni Corp. is planning to develop more than five times the offshore wind power capacity currently installed in Japan as it moves aggressively into a poorly developed area of the country's renewable energy market.

"If you want to do large-scale projects, it's offshore wind that has the most potential" among clean energy sources, Tomofumi Fukuda, who oversees power projects in Japan for the Tokyo-based trading company, said in an interview.

Marubeni will need to overcome several challenges for its plans to install more than 270 megawatts of offshore wind power capacity, among them a dearth of ships outfitted to install turbines off the coast. Japan had 52 megawatts of offshore capacity at the end of 2014, a fraction of the 2,715 megawatts onshore, according to Bloomberg New Energy Finance data.