May 13 (Bloomberg) -- United Photovoltaics Group Ltd. a Chinese solar-farm operator, said it will invest 10 billion yuan ($1.6 billion) this year to almost triple its solar power plant capacity.

It will buy 1 gigawatt of plants, Chief Financial Officer Li Hong said in an interview in Shenzhen yesterday. It currently operates 531.7 megawatts of solar projects and the acquisition may also include 100 megawatts of projects overseas.

United PV is increasing spending on solar farms as deadly pollution has fueled pressure on the government to declare war on smog, spurring demand for renewable energy. Its biggest shareholder China Merchants New Energy Group last month bought

13.6 million shares and increased its stake to 13.4 percent.

About 20 percent of the investment will come from their “own capital,” Li said. The company has about 500 million yuan in cash and will use loans to supplement the spending, he said.

The company said April 16 that it secured a finance lease of at least 10 billion yuan from China Financial Leasing Co.

China Merchants Group, parent of China Merchants New Energy Group, may provide further capital to its subsidiary to help raise funds for the expansion, Li said.

The stock rose 20 percent to HK$0.61 as of 1:11 p.m. in Hong Kong trading after earlier jumping as much as 33 percent, the most since Sept. 28, 2007.

United PV last month agreed to buy equity interests in 300 solar power projects to be developed by Yingli Green Energy Holding Co. from 2014 to 2016. The projects will be in provinces including Hebei, Guangxi, Shanxi and Shandong, Yingli said April 14.