March 30, 2026 — Southwest Research Institute (SwRI) is home to the first full-scale system showcasing a novel and commercially scaled method of industrial heat production, the Joule Hive™ Thermal Battery. The project is funded by the U.S. Department of Energy and led by Electrified Thermal Solutions. SwRI designed key support systems and oversaw construction of the system on its San Antonio campus.
Industrial processes typically burn fossil fuels for heat, emitting significant amounts of carbon dioxide (CO2). This contributes a significant percentage of global CO2 output, and most cannot switch to cleaner energy sources because they require temperatures and energy densities that are difficult to achieve without combustion.
“The technology SwRI will help to demonstrate is a purely electric system that could use renewable energy to generate and store heat up to 1,800 degrees Celsius with direct 13.2 kV (medium voltage) integration,” said SwRI’s Josh Schmitt, one of the project’s leaders. “This would eliminate the need for fossil fuels and cut gas bills creating a pathway for zero-emissions industrial heat in building heat, steel, cement, chemicals and other industrial applications.”
The core of the system uses fire bricks designed to withstand intense heat, specifically made to line firepits, kilns and stoves. These bricks are modified with conductive materials to retain large amounts of thermal energy and generate heat through electrical resistance.
“Electricity flows through the bricks at high voltages, generating resistive heat, which the bricks absorb,” Schmitt explained. “This thermal energy is stored inside the bricks until it’s needed, allowing the system to separate importing energy from the process of delivering heat to customers. The heat is delivered by blowing hot air, or any process gas, directly over the heated bricks with a blower, which goes into the process.”
The system’s thermal energy storage capabilities make it possible for industrial sites to use renewable energy flexibly. During especially sunny or windy periods, the system can charge itself by heating the firebricks. This makes it possible for sites to rely on renewable energy sources such as solar or wind, as they can store power for use when the sun isn’t shining or the wind isn’t blowing. The SwRI unit has a capacity of 20 megawatt-hours of heat.
“To host the system, SwRI expanded the infrastructure of its pre-existing High-Temperature Energy Conversion and Storage laboratory to include a 12,000 square-foot heavy-duty outdoor slab and 600 amps of electric power at 13.2 kV,” said Dr. Tim Allison, director of SwRI’s Machinery Department. “Our strategic investment in facility infrastructure supporting the Joule Hive project has established the capability to deploy zero-carbon heat at the MW scale. We are actively assessing the system’s output to validate pathways for integration into future site operations.”
“This project demonstrates a significant step forward in decarbonizing industrial heat systems, which have traditionally relied on carbon-based fuels,” Schmitt said. “By demonstrating a purely electric heating solution that can deliver temperatures up to 1,800 degrees Celsius, we’re not only providing a cleaner, more efficient alternative but also paving the way for industries to integrate renewable energy seamlessly into their operations. Additionally, it provides flexibility for industrial heat applications. It allows owners of the thermal storage to produce process heat from electricity when gas prices are high or provide an industrial site access to high-temperature heat when gas is not available.”
SwRI’s broad expertise in thermal energy systems has been key to providing the engineering, infrastructure and operational requirements necessary to develop, construct and test the technology. This includes designing and building the supporting infrastructure and integrating utilities required to operate the system as well as overseeing project testing and commissioning, addressing operational challenges and fine-tuning system performance. Additionally, SwRI developed innovative air transport, mixing and exhaust systems to ensure precise heat delivery for industrial applications.
Construction of the system began in August 2025 and was completed in December 2025.
For more information, visit Thermal Energy Storage or contact Joanna Quintanilla, +1 210 522 2073, Communications Department, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238-5166.