A power generation system and related method for repowering a fossil-fueled power plant using a carbon-free nuclear steam supply system (NSSS) which replaces the existing fossil plant steam generator which burns fossil fuel such as coal, oil, or natural gas. The existing fossil plant energy conversion system including the turbine-generator (turbogenerator) and auxiliary components of the Rankine cycle is retained. The NSSS may include a small modular reactor (SMR) unit comprising a reactor vessel with nuclear fuel core and steam generator which receives heated primary coolant from the reactor to produce main steam to operate the Rankine cycle. The main steam output by the SMR unit is compressed in a steam compressor to increase its pressure to a level necessary to operate the turbogenerator. The compressor may be operated via a portion of the main steam. An intercooler of the compressor may be used for main steam reheating.

The present invention provides an absorption-desorption based Carnot battery designed to achieve a high-efficiency, large-density, and low-loss conversion battery system for power-heat-power purpose. Based on the rational operating strategies, the current Carnot battery system design demonstrates outstanding energy storage density and round-trip efficiency, while the self-discharging loss is minimal even after prolonged standby time. The battery system of the present invention also enables further designs with flexibility in adopting different operating modes for versatile functions to provide electricity, heating, and cooling.

A power generation system and related method for repowering a fossil-fueled power plant using a carbon-free nuclear steam supply system (NSSS) which replaces the existing fossil plant steam generator which burns fossil fuel such as coal, oil, or natural gas. The existing fossil plant energy conversion system including the turbine-generator (turbogenerator) and auxiliary components of the Rankine cycle is retained. The NSSS may include a small modular reactor (SMR) unit comprising a reactor vessel with nuclear fuel core and steam generator which receives heated primary coolant from the reactor to produce main steam to operate the Rankine cycle. The main steam output by the SMR unit is compressed in a steam compressor to increase its pressure to a level necessary to operate the turbogenerator. The compressor may be operated via a portion of the main steam. An intercooler of the compressor may be used for main steam reheating.

Systems and methods for carbon dioxide-based energy storage and power generation are described. An example system is presented that includes a compressor operable to receive supercritical carbon dioxide (sCO.sub.2) and produce compressed sCO.sub.2, one or more thermal energy storage (TES) units operable to heat the compressed sCO.sub.2, a turbine operable to receive the heated and compressed sCO.sub.2 and output an sCO.sub.2 exhaust, and at least one of a generator or a propeller coupled to the turbine, where the generator is operable to produce electricity and the propeller is operable to produce thrust.

A charging circuit for converting electrical energy into thermal energy is provided, having a compression stage, connected via a shaft to an electric motor, a heat exchanger and an expansion stage, which is connected via a shaft to a generator, wherein the compression stage is connected to the expansion stage via a hot-gas line, and the heat exchanger is connected on the primary side into the hot-gas line, wherein the expansion stage is connected via a return line to the compression stage, so that a closed circuit for a working gas is formed. A recuperator is also provided which, on the primary side, is connected into the hot-gas line between the heat exchanger and the expansion stage and, on the secondary side, is connected into the return line, so that heat from the working gas in the hot-gas line can be transferred to the working gas in the return line.

The present disclosure provides pumped thermal energy storage systems that can be used to store and extract electrical energy. A pumped thermal energy storage system of the present disclosure can store energy by operating as a heat pump or refrigerator, whereby net work input can be used to transfer heat from the cold side to the hot side. A working fluid of the system is capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. The system can extract energy by operating as a beat engine transferring heat from the hot side to the cold side, which can result in net work output.

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. Configurations of simple cycle systems and combined cycle power plants using thermal energy storage units can provide even greater efficiency and responsiveness.

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. Configurations of simple cycle systems and combined cycle power plants using thermal energy storage units can provide even greater efficiency and responsiveness.