The illustration has been generated with the assistance of AI tools.
The district heating sector can already store around 100 GWh of energy. A new analysis shows that large-scale thermal energy storage will become an increasingly important part of the future energy system – with significant potential to expand storage capacity even further.
7 August 2026 | Original article in Danish by Flemming Linnebjerg Rasmussen, the Danish District Heating Association
Large-scale thermal energy storage is one of the most important – and often overlooked – enablers of district heating electrification.
According to a new analysis by the Danish District Heating Association, The Value of Electrified and Multi-Source District Heating, the district heating sector already has thermal storage capacity of around 100 GWh during the winter period. This is roughly equivalent to the amount of energy needed to charge around 1.5 million electric cars from 0 to 100%.
The analysis also shows that the value of thermal storage increases as district heating becomes more electrified.
“Thermal storage is what makes electrification work as an integrated system. It allows us to produce heat when it is most beneficial for the power system and deliver it when customers need it. This ability to separate production and consumption in time is one of district heating’s greatest strengths,” says Søren Lorenz Rask Søndergaard, Senior Consultant at the Danish District Heating Association.
Making electrification more valuable
Electrification is not simply about producing heat using electricity. Just as important is the ability to choose when that electricity is consumed.
Thermal storage makes it possible to decouple heat production from heat demand. Large heat pumps and electric boilers can therefore produce heat during hours when electricity is cheapest and most readily available, or when the power grid is under less pressure, while the heat can be delivered to customers later.
This means district heating companies can plan heat production based on both current and expected electricity prices. At the same time, large heat pumps and electric boilers become considerably more valuable to the power system because they can take advantage of periods with high electricity generation from wind and solar.
“The more district heating is electrified, the greater the value of being able to store heat. Storage gives us the flexibility to shift electricity consumption to the times when it creates the greatest benefit for both the power system and heat customers,” says Søren Lorenz Rask Søndergaard.
The analysis expects district heating companies to continue making substantial investments in heat pumps and electric boilers in the coming years. It therefore also identifies significant potential for further expansion of thermal storage capacity.
Thermal energy storage is set to become an increasingly important link between district heating and the power system.
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This article was translated into English by DBDH with the assistance of AI tools. The content has been reviewed and edited by the editorial team.
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