Multi-fluid, earth battery energy systems and methods

Abstract

The present disclosure relates to a system for storing and time shifting at least one of excess electrical power from an electrical power grid, excess electrical power from the power plant itself, or heat from a heat generating source, in the form of pressure and heat, for future use in assisting with a production of electricity. An oxy-combustion furnace is powered by a combustible fuel source, plus excess electricity, during a charge operation to heat a reservoir system containing a quantity of a thermal storage medium. During a discharge operation, a discharge subsystem has a heat exchanger which receives heated COfrom the reservoir system and uses this to heat a quantity of high-pressure, supercritical CO(sCO) to form very-high-temperature, high-pressure sCOat a first output thereof. The very-high-temperature, high-pressure sCOis used to drive a Brayton-cycle turbine, which generates electricity at a first output thereof for transmission to a power grid. The Brayton-cycle turbine also outputs a quantity of sCOwhich is reduced in temperature and pressure to a heat recuperator subsystem. The heat recuperator subsystem circulates the sCOand re-heats and re-pressurizes the sCObefore feeding it back to the heat exchanger to be even further reheated, and then output to the Brayton-cycle turbine as a new quantity of very-high-temperature, high-pressure sCO, to assist in powering the Brayton-cycle turbine.