Beijing, Oct 5 (IANS): Beijing will build four power centres by the end of 2014 to replace coal with natural gas in heating and power generation, authorities said Saturday.

Construction of the centres is part of the city's efforts to optimise energy mix and reduce emissions, according to officials of the Beijing Municipal Commission of Development and Reform, reports Xinhua.

With an investment of 47.7 billion yuan ($7.79 billion), the four power centres and 40 other related utility projects will reduce sulphur dioxide by 10,000 tonnes, provide heating for 100 million square metres and generate 7.2 million kilowatts of electricity through natural gas.

These services have so far been powered by four coal-fired power plants, which burned 9.2 million tonnes of coal in 2012, or 40 percent of the 23 million tonnes Beijing consumed in the same period. They will be shut down once the new power centres start operation.

Heavy smog shrouded Beijing's sky during the seven-day National Day holiday, prompting concern about worsening air pollution in the China's capital.