Creating industrial sized “underground batteries” from waste heat


Between 20 and 50 % of industrial energy output is lost as waste heat, according to the US Department of Energy. This loss is a needless drain on finances for industrial plants and creates enormous greenhouse gas emissions. Saving and storing this waste heat would reduce both costs and emissions.

Ruden Energy created its HEAT concept to store and recover seasonal waste heat from industrial processes, turning bedrock into large-scale natural thermal batteries. The stored heat can be recovered whenever needed.


Tromsø Kvitebjørn

The combustion plant at Kvitebjørn is currently developing a HEAT energy storage plant, in collaboration with Ruden Energy.

Energy storage for industrial waste heat

Ruden Energy has created the High Enthalpy Aquifer Technology (HEAT) system for underground energy storage. HEAT is particularly suitable for industrial plants with constant high levels of waste heat, as for example solid waste incineration plants.

Ruden Energy measures and models fractured rocks in the subsurface. By cementing and enhancing the fracture network, a reservoir is created for waste heat storage directly under an industrial plant.

Waste heat from the plant is stored in the rock formations by storing the heat in water, and circulating the water through the fractures in the bedrock, thereby taking advantage of the unlimited storage capacity of rocks. Surplus heat from district heating systems can be stored and exploited in this fashion.

The heat storage does not incur emissions and has minimal energy loss.

Concrete benefits

Ruden AS’ HEAT system provides clean energy storage for industrial plants, helping them to turn their waste heat into a seasonal productive resource. It moreover makes district heating plants more resource effective.

Seasonal storage recovers valuable energy that is otherwise lost, and therefore reduces carbon imprint while increasing profit.

ONS 2022 Winner Innovation Award SME RGB BLACK

Market potential

The potential for waste heat recovery in the EU is about 300 TWh per year, enough to power a medium-sized country for an entire year.

Ruden Energy is currently in the process of installing its HEAT system at Kvitebjørn Energi, which provides district heating for the town of Tromsø, Norway.

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