A CO2 Earth Battery system implemented with four concentric rings of horizontal injection and production wells is shown. Supercritical CO2 (sCO2)
from a fossil fuel power plant is pressurized for injection in the second ring of wells, which displaces brine produced at the inner ring. The produced
brine is heated, using heat from an above-ground source, such as a solar thermal farm, pressurized, and injected in the third well ring using excess
power from the grid. Gradually, the inner ring produces CO2, which is sent through a Brayton Cycle turbine and pressurized for injection in the second
ring. Hot brine produced at outer well rings is used to heat produced CO2, prior to being stored in a staging pond. When either waste or excess heat is
available, brine from the pond is heated and pressurized for injection in the third well ring, using excess power from the grid. To manage pressure,
some of the produced brine is diverted for consumptive use, such as in a reverse osmosis plant. The production of pressurized CO2 and brine can
be varied to provide dispatchable power to the grid. Although not shown in this figure, each well ring includes multiple horizontal wells.
Also not shown in this figure are field multi-fluidseparators that separate produced brine from the CO2 produced from the inner ring of wells.