The Chinese region of Inner Mongolia expects to start work this year on two new “flexible” power plants mixing coal and green energy.

The plants, which will provide power to the eastern economic hubs of Shanghai and Jiangsu province, mark a major strategic shift in the use of coal because the fossil fuel will now be used to plug gaps in the power generated by wind and solar energy rather than being the primary source of energy.

Inner Mongolia is home to around a quarter of China’s coal reserves but has also established itself as China’s biggest provider of renewable energy.

The autonomous region’s energy bureau said the National Energy Administration had approved plans for two power and transmission plants in the Kubuqi Desert.

The Shanghai plant will have the capacity to supply 8 gigawatts of solar power, 4.5 kilowatts of wind power, 2.6GW of supporting coal-fired power and 9 gigawatt-hours of new energy storage.

The Jiangsu plant is of a similar scale, although it has a slightly smaller wind and energy storage capacity, the regional authorities said.