A thermal energy storage (TES) system converts variable renewable electricity (VRE) to continuous heat at over 900 C. Intermittent electrical energy heats a solid medium. Heat from the solid medium is delivered continuously on demand. Heat delivery via flowing gas establishes a thermocline which maintains high outlet temperature throughout discharge. The delivered heat which may be used for processes including power generation and cogeneration. The thermal storage medium may constitute refractory material such as brick or concrete configured with radiation cavities and fluid flow channels to provide for rapid radiative charging from VRE and long-term convective discharging. Configurations of the thermal storage medium enable a substantially horizontal thermocline and heat delivery arrangement, which provides seismic stability and facilitates significant expandability of the TES system primarily by increasing the length of the system without adding undue height, contributing to both stability and efficiency of the heat delivery structure.

A system for heating and cooling buildings using geothermal heat storage includes a heat exchange system coupled to a heat storage medium including rock. The heat exchange system comprises pipes running through boreholes in the rock. The pipes of the heat exchange system are connected to pipes used within the building for heating and cooling the building. The system stores excess heat collected during the summer in the rock and discharges heat from the rock during the winter. The pipes of the heat exchange system may be arranged horizontally, and configured to run under the foundation of a building. Horizontal bores containing the pipes can be constructed using directional drilling techniques.

A system for heating and cooling buildings using geothermal heat storage includes a heat exchange system coupled to a heat storage medium including rock. The heat exchange system comprises pipes running through boreholes in the rock. The pipes of the heat exchange system are connected to pipes used within the building for heating and cooling the building. The system stores excess heat collected during the summer in the rock and discharges heat from the rock during the winter.

An integrated underground heat storage and heat transfer system is provided for CO2-based heating and cooling installations. The invention enables both energy storage and heat exchange in a single Underground Thermal Energy Storage (UTES) system. Excess heat produced during warm weather heats the ground to relatively high temperatures, which in cool weather serves as an artificial geothermal source. A geothermal heat pump (GHP) system reclaims this heat during cool weather. When the GHP is reversed in warm weather, the rejected heat is sent to a separate loop installed in cold earth.

A thermal energy storage (TES) system converts variable renewable electricity (VRE) to continuous heat at over 900 C. Intermittent electrical energy heats a solid medium. Heat from the solid medium is delivered continuously on demand. Heat delivery via flowing gas establishes a thermocline which maintains high outlet temperature throughout discharge. The delivered heat which may be used for processes including power generation and cogeneration. The thermal storage medium may constitute refractory material such as brick or concrete configured with radiation cavities and fluid flow channels to provide for rapid radiative charging from VRE and long-term convective discharging. Configurations of the thermal storage medium enable a substantially horizontal thermocline and heat delivery arrangement, which provides seismic stability and facilitates significant expandability of the TES system primarily by increasing the length of the system without adding undue height, contributing to both stability and efficiency of the heat delivery structure.