The trillion barrel oil shale and oil sand deposits in North America offer the potential to make the less energy dependent on unreliable foreign sources. However, if these unconventional deposits were produced using existing combustion processes, substantial CO2 emissions would be injected into air. To avoid this green house gas problem and yet produce liquid fuels, a wind powered electrothermal energy storage system is described. It stores the unpredictable intermittent wind electrical energy as thermal energy over long periods in thick fossil hydrocarbon deposits. Because thermal diffusion time is very slow in such deposits, thermal energy is effectively trapped in a defined section of the hydrocarbon deposit. This allows time for the thermal energy to convert hydrocarbons into gaseous and liquid fuels. The process is highly energy-efficient and makes available considerably more energy than was expended during the heating. In addition, the method can increase the reliability of the grid and provide a load-leveling function. The wind-powered electrothermal conversion method produces substantially less CO2 than traditional shale oil extraction processes or renewable energy processes that employ a combustion step to produce the fuel.