Steam generator

An apparatus for utilizing fossile fuels still in the ground as an energy source, comprising a bore hole extending from the earth's surface to underground fossile fuel, a cap closing the upper end of said hole, a first conduit leading from above ground through said cap to adjacent the fuel, said cap having a bore through which an igniter can be utilized for igniting the fuel, a closure for sealing said cap bore after the fuel is ignited, means supplying air from above the earth's surface through said first conduit to the burning fuel, a second conduit opening into the bore hole through said cap to receive heat from the burning fuel, an electric generator, and a heat exchanger connected to said second conduit and to the generator for utilizing the heat to drive the generator.