Electric grid operators and utilities around the world must adapt to a rapidly changing energy landscape. Electricity generation is undergoing its biggest shift since the dawn of the grid, as falling costs of wind and solar bring record-breaking deployments of variable renewables online.

Meanwhile, rising demand, rapid electrification and new opportunities for load flexibility and responsiveness present both new challenges and new tools. As these changes lead to increasing variability and market volatility, new approaches are needed to manage supply and demand, support existing infrastructure and continue new investments in our energy system.

An emerging opportunity to help manage and balance the changing grid comes from thermal energy storage. Thermal batteries store electricity as heat, soaking up energy during periods of high generation and low demand. They use that heat to power always-on industrial energy loads in industries ranging from chemicals to food to steel. Because of their long duration, low cost and rapid charging capabilities, they are uniquely suited to enable a more efficient and reliable grid in the face of these emerging challenges.

In addition to providing clean energy for nearly every industrial sector, thermal batteries have the potential to serve as a linchpin for a reliable low-emissions grid, mitigating the variability of renewable generation and electrifying industrial heat loads without increasing peak demand or raising costs for ratepayers.

Variable, low-cost resources are transforming electricity markets

As more wind and solar are deployed on the grid, their variability increasingly leads to market conditions that would be unheard of in a fossil-dominated grid. With zero marginal cost generation, renewables fare well in competitive markets during times of high electricity demand. However, when renewable production is high and demand is low, or when low-cost production is stuck behind transmission constraints, wholesale power prices plummet and generation resources worth millions of dollars are often curtailed.

Such imbalance in renewable supply and grid demand is not rare. In fact, in many parts of the country it is one of the biggest drivers of wholesale electricity pricing today. In regions with high penetrations of renewable energy, electricity prices frequently dip to or even below zero, often leading clean energy generators to cease production altogether. Across the “Wind Belt” of the U.S. Midwest, nearly 10% of wind production curtailed, amounting to nearly 10 TWh of wasted energy each year — enough to power nearly a million American homes. For some wind generators, curtailment rates are as high as 20%.

To access cheap energy, flexibility is king

Intermittent electricity from wind and solar may at first seem ill-suited to meet the needs of the industrial sector, where manufacturers typically operate 24/7 and can’t afford unplanned downtime. But when paired with thermal storage, this clean generation opens an opportunity that was previously impossible: powering industry with ultra-low-cost electricity that’s cheaper than the fuels available to industry today. In the Central U.S. Southwest Power Pool region, for instance, over 20% of hours of wholesale electricity prices are already below the country’s cheapest natural gas.

Accessing this ultra-cheap electricity requires immense flexibility. Thermal batteries can meet this challenge by using only the cheapest hours of electricity generation: they charge by running electricity through a resistive heating element, just like a toaster, rapidly soaking up energy when it’s cheap and available and storing it in highly insulated containers. By storing and continuously outputting this energy for long periods of time — multiple days in the case of Antora’s thermal battery — thermal batteries can be extremely flexible in their charging patterns while still delivering always-on heat. This flexibility creates an opportunity to provide a low-cost, low-carbon, domestic energy supply to U.S. manufacturers without impacting peak demand or requiring the expensive buildout of new grid infrastructure.

Thermal batteries enable a more efficient and reliable grid

The immense flexibility of thermal storage enables industrial facilities to make valuable use of low-priced electricity that might otherwise be curtailed or sold for negative prices, enabling better utilization of existing grid assets and reducing utilities’ and asset owners’ exposure to market risks. This same flexibility enables thermal batteries to ramp up and down to meet the needs of grid operators, increasing efficiency and resilience across the system.

Currently, rapid renewable growth within a region can lead to diminishing returns on new investments as supply overtakes demand for parts of the day. Thermal batteries change the equation by providing flexible demand for low-cost generation, regardless of the time of production, thereby lifting demand when electricity generation has little or no value elsewhere on the grid. By providing a valuable use for low-value power — and therefore additional revenue to renewable generation assets — thermal batteries also support further investment in the buildout of low-cost new renewable generation on the grid.

Stabilizing the grid while supporting a U.S. industrial renaissance

Thermal batteries can increase U.S. manufacturing competitiveness by providing a low-cost and low-carbon energy source for American factories. The same advantages that thermal batteries hold for industry — such as low costs, fast charging and long storage durations — also position thermal batteries as one of the most flexible assets to ever operate on the grid. This flexibility enables the technology to increase grid resilience, make better use of existing assets and spur investment in the buildout of new low-cost generation.

In the face of changing electricity markets and growing electricity demand, thermal batteries offer American industry a low-cost and dynamic energy source, creating value by making more efficient use of our existing electricity system and driving emissions reductions across both industry and the grid.