Chinese scientists have devised a new use for old oil and gas wells that could provide access to geothermal energy.

Xianbiao Bu and his colleagues at the Chinese Academy of Sciences, Guangzho, China, are suggesting that deep, old, oil and gas wells could be retrofitted to circulate water that could be heated by geothermal energy and brought to the surface to generate power.

In an online article in Renewable Energy, the scientists explained that the largest cost for tapping geothermal energy is the cost of drilling the wells. By retrofitting these old wells, geothermal energy could be developed at a lower cost.

Each well could generate an estimated 54 kilowatts of electricity. Although a small amount of power, it could add to available renewable energy.

The scientists said two strings of pipe could be run in each well. Water would be pumped down the inner pipe, be heated and then pumped up the annulus to the surface where it could run a turbine.