Solar Thermal Energy Storage

Titanium Hydride for Solar Thermal Energy Storage

Our group is a partner in the ARPA-E/DOE funded program at Pacific Northwest National Laboratory (PNNL). This program exploits recent breakthroughs with metal hydride materials and system design to demonstrate proof of concept for novel hydride-based thermal storage that far exceeds the DOE€™s performance and cost targets.  Reversible Metal Hydride Thermochemical (RMHT) systems offer a transformational advancement in thermal energy projected to achieve exergetic efficiencies of 95% at an operational temperature range of 600°C €“ 800°C, while lowering costs.  RMHT systems are a revolutionary change because they store enormous amounts of thermal energy via endo/exothermic reversible reactions resulting in a factor of two to twenty times increase in thermal energy storage, i.e. > 2000 kJ/kg and > 5000 kJ/dm3 compared to the current state of the art. Since the hydrogen is recycled during the storage and release processes, round trip exergetic efficiencies are projected to be ~95%.  During this seed project, the PNNL-University of Utah team will transition this technology forward to attract additional government and private sector investment by reducing technology risk in two ways: 1) By demonstrating the desired cycle life in a reversible hydride at 700°C, and 2) Through design, construction and operation of a 3 kWh prototype with energy storage densities and exergetic efficiencies that meet or exceed ARPA-E targets.

The purpose of the proposed R&D project is to transform thermal energy storage (TES) technology by demonstrating, in proof of concept, a high-temperature thermal energy storage based on the concept of high-energy density dual bed metal hydrides.