Overseas investments last year ranged from lithium battery makers in Australia and Chile to an electricity distribution deal in Brazil and the building of a solar cell factory in Vietnam. China now owns five of the six largest solar module manufacturing firms in the world, according to the report. On the domestic front, the world's second-largest economy had already emerged as a renewable powerhouse, outstripping the United States. China poured more than $100 billion in domestic renewable energy -- the wind, solar, hydro -- and related sectors in 2015, more than double the US investment, according to Bloomberg New Energy Finance. "The US is already slipping well behind China in the race to secure a larger share of the booming clean energy market," said IEEFA director Tim Buckley. "With the incoming (US) administration talking up coal and gas, prospective domestic policy changes don't bode well," he said in a statement.