Publications Details
High Performance Reduction/Oxidation Metal Oxides for Thermochemical Energy Storage (PROMOTES) /CSP
Thermochemical energy storage (TCES) offers the potential for greatly increased storage density relative to sensible-only energy storage. Moreover, heat may be stored indefinitely in the form of chemical bonds via TCES, accessed upon demand, and converted to heat at temperatures significantly higher than current solar thermal electricity production technology and is therefore well-suited to more efficient high-temperature power cycles. However, this potential has yet to be realized as no current TCES system satisfies all requirements. This project involves the design, development, and demonstration of a robust and innovative storage cycle based on redox-active metal oxides that are Mixed Ionic-Electronic Conductors (MIECs). We will develop, characterize, and demonstrate a first of its kind 100kWth particle-based TCES system for direct integration with combined-cycle Air Brayton based on the endothermic reduction and exothermic reoxidation of MIECs. Air Brayton cycles require temperatures in the range of 1000-1230 °C for smaller axial flow turbines and are therefore inaccessible to all but the most robust storage solutions such as metal oxides. The choice of MIECs, with exceptional tunability and stability over the specified operating conditions allows us to optimally target this high impact cycle and to introduce the innovation of directly driving the turbine with the reacting/heat recovery fluid. The potential for high temperature thermal storage has direct bearing on next-gen CSP, and an appropriate investment for SETO.