Solar and wind power are being introduced into electric grids to supplement and replace conventional electricity. Unfortunately, the deployment of utility-scale storage has not kept pace with the variable nature of solar and wind. Cost effective large-scale energy storage is required for additional solar and wind renewable energies. The Geothermal Battery Energy Storage concept has the potential to provide this large-scale energy storage using a renewable energy source.

The concept uses solar radiance to heat water on the surface and then inject this heated water deep into the earth. This hot water would elevate the formation temperature creating a high temperature "geothermal reservoir" acceptable for conventional geothermal energy recovery. The unique feature is the use of sedimentary basins with high porosity and high permeability, at depths great enough to allow high temperature water injection and production. The process uses the produced formation water; and thus, neither fresh water nor surface storage or disposal of water is required. Furthermore, calculations show that nearly one hundred percent of the heat injected can be recovered for certain reservoirs.

Since there are many parameter variations possible for different reservoirs and injection-production cases, calculations are needed to consider the effects. This paper presents parametric calculations for permeability, porosity, reservoir thickness, injection rate, and other variables. Temperature and reservoir pressure profiles at distances away from the injection well and the production well are shown. For the calculations, the reservoir is considered to be homogeneous but with different horizontal to vertical permeabilities. Total heat recovered is shown for different parameter variations and different number of cycles of injection-production.

Key parameter effects on the produced water temperature and on the injection and production pressures are discussed. Being able to recover nearly one hundred percent of the heat injected dramatically increases the potential for large-scale thermal energy storage for daily, monthly, or even seasonal cyclic electric generation.

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