For thermal batteries, continuous delivery matters more than peak temperature

Inflexible industrial loads and variable generation have increased grid volatility, driving higher prices during peak demand, while at the same time creating extended periods of low power prices during off-peak hours.

This year, the US set record highs for peak demand, yet the valleys remain relatively flat. For manufacturers, this volatility directly affects competitiveness. Electricity is more expensive when it is needed most, and increasingly cheap when it is not. The result is higher operating costs, greater exposure to price swings, and pressure on margins.

Energy storage is the mechanism that connects these two realities. By absorbing excess generation in low-price windows and storing it when demand is high, storage reduces grid instability and lowers delivered energy costs.

For industry, thermal energy storage (TES) is not an abstract transition technology — it is a tool to reduce input costs, improve resilience, and make operations more predictable.

As manufacturers look at electrifying their heat systems, one question dominates: Should plants be redesigned around lower delivered temperatures, or should storage systems be deployed that match the performance of existing equipment?

That decision requires distinguishing between peak temperature and continuous delivered temperature — two metrics that are frequently treated as interchangeable. Many storage technologies can reach impressive internal temperatures—1,000°C or more—but cannot deliver anything close to that consistently under load.

For an industrial process, that distinction determines whether a thermal storage system can complement or match fossil fuel heat delivery or if the new system requires a costly redesign of the entire process.

Picture a car: it may be rated for 150 miles per hour and 40 miles per gallon. Those numbers are technically accurate on their own, but they’re never achieved together — you don’t get 40 mpg at 150 mph. Similarly, some thermal batteries can reach 1,000°C, and some can discharge for 24 hours, but no system, until now, can do both at the same time.

This is where the problem lies for manufacturers. A chemical reactor or cement kiln doesn’t benefit from a brief moment at 1,000°C if the delivered temperature drops to 400–500°C during normal operation. Combustion systems don’t behave like this; they deliver 1,200–1,800°C continuously, with the stable, predictable profiles that industrial processes depend on.

When a thermal battery is marketed based on peak temperature alone, it creates the illusion of fossil-comparable performance without the actual ability to sustain it. And sustaining it is what determines whether electrification can happen economically.

If a system’s delivered temperature is too low or too unstable, the factory must redesign heat exchangers, change residence times, alter material handling, or redesign entire process steps. That can be far more expensive than the benefits of the heat system itself.

So why does this confusion persist? Partly because peak temperature is easier to market. “1,000°C storage” is more eye-catching than “450°C delivered,” even though only the second number matters in practice, partly because sustaining high heat is an inherently harder engineering challenge than reaching it once.

Many current systems built around large blocks of stored heat such bricks, molten media, or packed beds have temperature curves that naturally slope downward as they discharge. These technologies may still be valuable, but they are not drop-in complements for fossil fuel combustion, and the market needs to understand that difference clearly in order to reduce manufacturing costs and remain competitive on the global stage.

As subsidies and incentives soften, this clarity becomes even more important. In the US during the height of Inflation Reduction Act (IRA) and Department of Energy (DOE) enthusiasm, buyers could afford to experiment—trying early-stage systems, signing for small pilots, and running tests at the margins.

Today, procurement teams are asking sharper questions:

• What temperature can this system deliver continuously?
• For how long?
• How much does output drop over a standard shift?
• What retrofits are required to accommodate that drop?
• And is the system genuinely capable of replacing gas, or is it redefining the process around its own limitations?

These are healthy questions, and the industry should embrace them. Thermal storage is too important for ambiguous metrics. As heavy industry faces increasing power costs and uncertain grid stability, the winners will be the technologies that behave like the fossil systems they are meant to complement: stable, high-temperature, controllable, and continuous.

Thermal storage has enormous potential. It can shave peak loads, support industrial demand, stabilise power markets, and unlock energy systems at scale. However, industrial customers need clarity. The market needs honesty, and the technologies designed for continuous, combustion-compatible performance are the ones that will ultimately win the race to electrification.

About the Author

Romano Pasquale serves as CEO and member of the board of directors for Redoxblox, a thermochemical energy storage company. With over 35 years of experience as a serial founder and CEO, he has led four successful companies to exits and has deep experience assembling teams, developing business models, guiding engineering development, and scaling manufacturing to deploy innovative technology solutions as commercial products