Storage

The Michigan State University team will develop a modular thermal energy storage system that uses electricity from sources like wind and solar power to heat up a bed of magnesium manganese oxide (Mg-Mn-O) particles to high temperatures. Once heated, the Mg-Mn-O will release oxygen and store the heat energy in the form of chemical energy. Later, when additional power is needed, the system will pass air over the particle bed, initiating a chemical reaction that releases heat to drive a gas turbine generator.

Form Energy will develop a long-duration energy storage system that takes advantage of the low cost and high abundance of sulfur in a water-based solution. Previous MIT research demonstrated that aqueous sulfur flow batteries represent the lowest chemical cost among rechargeable batteries. However, these systems have relatively low efficiency. Conversely, numerous rechargeable battery chemistries with higher efficiency have high chemical costs. The solution requires low chemical cost, high efficiency, and streamlined architecture.

The Antora Energy team will develop key components for a thermal energy storage system (solid state thermal battery) that stores thermal energy in inexpensive carbon blocks. To charge the battery, power from the grid will heat the blocks to temperatures exceeding 2000°C (3632°F) via resistive heating. To discharge energy, the hot blocks are exposed to thermophotovoltaics (TPV) panels that are similar to traditional solar panels but specifically designed to efficiently use the heat radiated by the blocks.

The National Renewable Energy Laboratory team will develop a high-temperature, low-cost thermal energy storage system using a high-performance heat exchanger and Brayton combined-cycle turbine to generate power. Electric heaters will heat stable, inexpensive solid particles to temperatures greater than 1100°C (2012°F) during charging, which can be stored in insulated silos for several days. To discharge the system, the hot particles will be fed through the fluidized bed heat exchanger, heating a working fluid to drive the gas turbine attached to a generator.

The Quidnet Energy team will develop a modified pumped hydro energy storage system that stores energy via high-pressure water in the subsurface. To charge, the team will pump water into confined rock underground, creating high pressures. When energy is needed later, the pressure forces water back up the well and through a generator to produce electricity. The Quidnet team will demonstrate the reversibility of this process and the ability to translate it across multiple types of geography within the U.S.

The Brayton Energy team will develop a key component to enable a cost-competitive Laughlin-Brayton battery energy storage system that combines thermal storage and innovative turbomachinery to generate power. When the system is charging, an electrically driven heat pump will accumulate thermal energy in a high temperature thermal energy storage medium. During discharge, electricity is produced by heating a gas using the stored thermal energy and sending it through the generation turbine that drives an electric generator.

The United Technologies Research Center team will develop an energy storage system based on a new flow battery chemistry using inexpensive and readily available sulfur and manganese based active materials. The team will employ innovative strategies to overcome challenges of system control and unwanted crossover of active materials through the membrane. The affordable reactants, paired with the unique requirements for long-duration electricity discharge, present the opportunity for very low cost energy storage.

The University of California, San Diego (UC San Diego) will conduct testing of existing ARPA-E energy storage technologies in both laboratory and grid-connected conditions. Home to one of the country’s largest microgrids, UC San Diego will apply its advanced understanding of microgrid operation in the California market to select and value applications for storage, in grid-connected and islanded conditions, and to develop duty cycles for energy storage in order to serve individual and stacked applications.

Det Norske Veritas (DNV GL) and Group NIRE will provide a unique combination of third-party testing facilities, testing and analysis methodologies, and expert oversight to the evaluation of ARPA-E-funded energy storage systems. The project will leverage DNV GL’s deep expertise in economic analysis of energy storage technologies, and will implement economically optimized duty cycles into the testing and validation protocol.

Southwest Research Institute (SwRI) is developing a battery management system to track the performance characteristics of lithium-ion batteries during charge and discharge cycles to help analyze battery capacity and health. No two battery cells are alike—they differ over their life-times in terms of charge and discharge rates, capacity, and temperature characteristics, among other things. In SwRI's design, a number of strain gauges would be strategically placed on the cells to monitor their state of charges and overall health during operation.