China may be the world's biggest polluter, but the country is certainly taking commendable steps towards a cleaner energy future. The latest example is a trial conducted in the country's northwest, which saw the Qinghai Province run on 100 percent renewable energy for seven days straight.

China's rapid industrialization has seen it claim the mantle as the world's largest emitter of C02, some 10,357 million metric tons per year, according to the Global Carbon Project. What that means for global warming is one thing, but that pollution is also devastating for air quality, as coal combustion contributes an estimated 40 percent of the country's harmful PM 2.5 particles.

So China is making huge investments to rectify the problem, pumping US$102.9 billion into renewables in 2016, more than one third of the world total. The country now installs a soccer field's worth of solar panels every hour, and installed two wind turbines every hour across 2015.

In the Qinghai Province, which is home to around 6 million people, the focus is on solar and hydro power in particular. The power grid has a total installed capacity of 23.4 million kW, and last month, around 83 percent of that came from solar, wind and hydro power.

The State Grid Corporation put that potential into practice between June 17 and June 23, running the entire province on power generated by solar, wind and hydro. During this period, 1.1 billion kWh hours were used, which is equivalent to 535,000 tons of coal. 72.3 percent of this came from hydro, and the remainder from wind and solar.

"Being the first trial of this kind in the country and a major step in the transformation of energy supply, it will be of great importance in promoting the use of clean energy in China in a sustainable and effective way," said Quan Shenming, General Manager of Qinghai Electric Power Corporation, a subsidiary of State Grid Corporation.

According to Climate Action, a partner of the United Nations Environment Programme, China will invest a mammoth $366 billion into renewables by 2020.