The vast North American oil shale and tar sand deposits offer the potential to make USA energy independent. However, if these deposits were produced by the existing combustion processes, substantial CO2 emissions would be injected in to air. To avoid this green house gas problem and yet produce liquid fuels, an electro-thermal energy storage system that may be wind-powered is described. It stores the unpredictable, intermittent (e.g., wind) electrical energy over long periods as thermal energy in fossil hydrocarbon deposits. Because the thermal diffusion time is very slow in such deposits, the thermal energy is effectively trapped in a defined section of a hydrocarbon deposit. This allows time for the thermal energy to convert hydrocarbons into gaseous and liquid fuels. It can also use a portion of the fuel to regenerate electrical power into the electrical grid of higher energy content than was initially stored. In addition, the method can increase the reliability of the grid and provide a load leveling function.