The capital has long pledged to improve air quality by reducing the use of coal, which produces fine particles when burned that are crucial to the formation of smog.
BEIJING'S last large coal-fired power plant has suspended operations, meaning the capital has become the first city in China to have all its power plants fueled by clean energy.
The city also draws electricity from coal-fired power plants in neighbouring provinces such as Hebei and Inner Mongolia, where environmental regulations are weakly enforced. The city has been closing down its coal fired electricity units since 2014.
The shuttering of the Huangneng Beijing Thermal Power Plant comes on the heels of China's annual legislative sessions, where Premier Li Keqiang promised to "make our skies blue again" in his state-of-the-nation speech.
Cai said a new power plant that will use natural gas as fuel is under construction and will start operating soon, adding that the municipal government will provide support to the company during transition.
Following its closure on Saturday, emissions of 1.76 million tonnes of coal, 91 tonnes of sulphur dioxide and 285 tonnes of nitrogen oxide will be reduced annually, state-run agency Xinhua reports.
Under the plan, Beijing will build no more large-scale power plants. Its five generator arrays, with a total energy capacity of 845 megawatts, burned more than 8 million tonnes of coal per year.
To take its place, Mitsubishi Hitachi Power Systems supplied four gas turbines, at least two of which will operate in a combined cycle configuration for cogeneration purposes.