Thermal batteries have the potential to assist in reducing emissions in hard-to-decarbonize sectors, such as manufacturing and heavy industries like cement and steel production. Rondo has announced a significant development in demonstrating the practical application of thermal energy storage.
The thermal battery concept involves using electricity to heat durable materials, such as bricks, and storing that heat for later use in industrial processes or electricity generation. Rondo’s latest system has been operational for ten weeks and reportedly meets various efficiency and reliability benchmarks. The system can heat bricks to temperatures exceeding 1,000 °C (approximately 1,800 °F), with over 97% of the input energy being returned as usable heat.
This new system marks an advancement from Rondo’s earlier 2 MWh pilot project initiated in 2023, and it represents the first mass-produced heat battery the company plans to deliver to customers. Given that 20% of current energy demand is utilized for industrial heating, which predominantly relies on fossil fuels, the success of this technology could play a role in climate action.
However, it is important to note that this particular system is being utilized for enhanced oil recovery, a practice that involves injecting steam into wells to extract oil. This raises questions about the alignment of climate technology with fossil fuel production, as some critics argue that such practices may prolong reliance on polluting infrastructures.
In discussions, Rondo’s founder and chief innovation officer, John O’Donnell, defended the decision to engage with the oil and gas sector, indicating a complex relationship between advancing clean technology and fossil fuel extraction. The implications of this approach within the broader context of climate action remain to be fully evaluated.
Source: https://www.technologyreview.com/2025/10/23/1126419/thermal-batteries-energy-storage/