Drive to install rooftop solar panels on homes, factories and public buildings

China, the world's biggest solar market for two years running, is pushing to install more panels at factories, schools and even greenhouses as it seeks to meet its goals under a historic climate agreement with the US.

China expects to install up to 8gigawatts of small solar systems this year, more than 10 times the amount installed last year. The country had almost 20GW of solar capacity at the end of last year, equivalent to about 20 nuclear reactors. Most of that came from massive solar farms in remote areas and policymakers are now promoting smaller systems closer to where they are needed.

The push to promote wider use of rooftop solar comes amid growing health concerns about smog from residents and foreign companies. It also adds to the nation's push to be a leader within the global climate community.

Solar's proportion of electricity generation capacity rose to 2 per cent, from 0.08 per cent four years ago, which was double nuclear power's share last year.

"Rooftop solar is actually the most attractive because it eliminates transmission and distribution investment," said Ahmad Chatila, chief executive officer of US-based producer SunEdison.

Producing so much power in isolated areas creates bottlenecks in the grid. So-called distributed power, smaller systems installed locally, eliminates the need for costly transmission cables and will speed the country's transition away from the coal-fired power plants that help create some of the world's dirtiest air.

SunEdison is in talks with a Chinese partner to build a factory in the country and has agreed to jointly create a US$220 million fund to develop up to 1GW of solar projects there. China's distributed solar market was going to be "enormous", Chatila said.