Thermal batteries: The why, what, and how of this technology that’s helping eliminate fossil fuel combustion in industrial heating.
Thermal batteries are hot. The technology, which promises to provide a cheaper, cleaner alternative for some of the roughly 20 percent of global energy consumption — usually derived from fossil fuels — that goes into industrial heating, is causing a lot of excitement, ranking as the reader’s choice for 2024 breakthrough technologies in MIT Technology Review.
Heat has long been a challenge in slashing carbon pollution from industrial processes. On-demand heat — including at temperatures of greater than 1,000°C, hot enough to melt glass — is necessary for a wide range of industrial applications, including food and beverage production, pulp and paper manufacturing, glassmaking, steelmaking, and most chemical manufacturing. By converting low-cost, low-value hours of electricity production into energy stored for long durations as high temperature heat, thermal batteries can deliver industrial heat and power cost-effectively and on demand, day or night, solving this crucial problem.
Thermal batteries aren’t just an industrial solution, they can also serve as backup energy for the grid, especially at times when other renewables production is low.
So how do they work? CLICK HERE to read about steps below outline the process:
- Charging: Electricity, typically from renewable sources like wind or solar power when they are in oversupply and without impacting coincident peak loads, is drawn into the thermal battery system.
- Conversion: The electricity is converted into thermal energy, typically through resistive heating, where electricity is passed through a material with high electrical resistance, generating heat — just like a toaster.
- Storage: The heat is then stored in a high-heat capacity medium such as “hot rocks” like graphite, crushed rock, and bricks, or thermochemical media.
- Insulation: The heated material is held in an insulated environment to maintain temperature for very extended periods — from tens of hours to multiple days.
- Delivery: When needed, the stored heat is released, delivering on-demand energy to industrial processes or heating systems.
Excerpted from an article originally published on February 3, 2025 by Colm Quinn, Nathan Iyer, David Hynek, Ankur Dass
