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.