As Goldman Sachs Group Inc. and billionaire Masayoshi Son lead a swarm of investors seeking to exploit Japan's solar power subsidies — the largest in the world — Sumitomo Corp. is betting on wind.

Trading house Sumitomo, Japan's second-largest investor in power generation outside utilities, will add wind farms and at least two biomass plants to take advantage of the above-market rates for electricity from renewable sources the government introduced in July.

Sumitomo's utility, Summit Energy Corp., expects profits from wind power to triple in as many years, according to the unit's president, Shinichi Kitamura.