Echogen will lead the conceptual design and modeling of a sCO2 power cycle for the TCES application. Southern Research will continue the development, testing, and optimization of MgO sorbent materials. The teams will combine to complete the conceptual design of a prototype TCES reactor for a test program to be conducted at Echogen’s prototype sCO2 test loop. The prototype system will be fabricated and tested over a large number of simulated solar storage and discharge cycles.
The thermochemical energy storage proposed here involves the reaction of a gas-phase material with a solid-phase material. The transport of heat into and out of such systems has traditionally been a challenge. It is also challenging to manage the large volumes of gas-phase material when it is not reacting. By direct-contacting the power cycle’s working fluid (sCO2) with the TCES, the gas-phase reactant and power cycle working fluid both experience efficient heat transfer. The effect of the reaction is a manageable increase or a decrease to the existing inventory of sCO2. This allows the CO2 reactant storage to be combined with the sCO2 power cycle equipment in a way that will greatly reduce the size and cost of the storage system. In addition, the thermochemical reaction occurs over a narrow temperature range, allowing tight integration with the sCO2 power cycle and cycle efficiency improvements.