XINING, June 20 (Xinhua) -- Northwest China's Qinghai Province on Wednesday started a nine-day all clean energy power supply project following a successful seven-day trial last year.

The province plans to use all green energy sources to generate electricity from June 20 to 28 to promote the use of clean energy.

As the source of China's three major rivers, the Yellow, Yangtze and Lancang, Qinghai has strong hydro-power and solar supplies, and a population of 5.8 million people.

Last year, from June 17 to 23, the province ran entirely on renewable energy, using wind, solar, and hydro power.

During that period, hydro power plants supplied 72.3 percent of the electricity, with new energy sources such as wind and solar supplying the remainder.