Electricity Generation and Delivery

Stanford University will develop a machine-learning enhanced framework for the design of optical communications components that will enable them to operate at their physical performance limits. Information processing and communications systems use a significant fraction of total global energy. Data centers alone consume more than 70 billion kilowatt-hours per year. Much of this energy usage is intrinsic to electronic wiring. However, optical-based technologies offer a promising option to reduce energy consumption.

Iowa State University will develop novel machine learning tools to accelerate the inverse design of new microstructures in photovoltaics. The team will create a new deep generative model called bi-directional inverse design networks to combat challenges in real-world inverse design problems. The proposed inverse design tools, if successful, will produce novel, manufacturable material microstructures with improved electromagnetic properties relative to existing technology for better, more efficient solar energy.

The University of Tennessee, Knoxville team will develop an energy storage system based on an innovative electrolyzer/fuel cell combination. Typically, fuel cells produce water from hydrogen and oxygen. The Tennessee team will instead use the fuel cell to produce hydrogen peroxide, a liquid that can be stored. When extra power is needed on the grid, the fuel cell will produce peroxide and electricity. Available electricity then can be used to convert the peroxide back to hydrogen and oxygen during the charging cycle, which can be stored for future use.

The Echogen Power Systems team will develop an energy storage system that uses a carbon dioxide (CO2) heat pump cycle to convert electrical energy into thermal energy by heating a “reservoir” of low-cost materials such as sand or concrete. During the charging cycle, the reservoir will store the heat that will be converted into electricity on demand in the discharge or generating cycle. To generate power, liquid CO2 will be pumped to a supercritical pressure and brought to a higher temperature using the stored heat from the reservoir.

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.