District heating companies are the largest flexible electricity consumers in Denmark. Using their large thermal storage tanks, they can store cheap electricity as hot water for later use. In addition, electric boilers help balance the electricity system by quickly adjusting consumption up or down to match fluctuations in supply and demand.
By Kia Marie Jerichau, Head of Flexibility and Balancing, Energinet
Solar power often reduces electricity prices during midday hours in the spring. This benefits district heating customers when electric boilers are activated to produce inexpensive, environmentally friendly heat. If a cloud suddenly reduces solar output and causes an imbalance in the grid, district heating plants are ready to respond.
Through the balancing market, Energinet can activate district heating plants to pause consumption, helping to stabilize the grid until production normalizes. The same flexibility applies when wind turbines generate more electricity than expected—electric boilers can ramp up to absorb the surplus, preventing production loss.
The figure illustrates flexible electricity consumption by the district heating sector during periods of low electricity prices, which typically coincide with high solar and wind power production. Yellow represents solar output, green represents wind output, red indicates electricity consumption by district heating systems, and the dashed line shows electricity prices.
While we wait for Power-to-X
District heating is currently one of the largest flexible electricity consumers, playing a crucial role until future technologies, such as Power-to-X, can also deliver flexible demand.
“District heating has a built-in advantage when it comes to balancing the power system: our pipes and storage tanks act as energy reservoirs,” says Michael Søgaard Schrøder, Chief Consultant at the Danish District Heating Association. “We can absorb excess electricity from solar and wind and shut down electric heaters in response to rapid shifts. In this way, district heating supports the power system with balancing capacity and storage options that the grid itself lacks.”
Energinet welcomes this contribution. Kia Marie Jerichau, Head of Flexibility and Balancing at Energinet, adds:
“At Energinet, we welcome actors of all sizes—and district heating is clearly in the top league. The interest in balancing the grid has grown significantly. In 2024, we saw a sevenfold increase in new participants in the balancing market compared to 2023. We need all kinds of contributors, whether greenhouses, swimming pools, or networks of charging electric vehicles. Only imagination sets the limit,” says Jerichau.
Energinet currently spends DKK 2–2.5 billion annually on system services to maintain grid balance.
For further information, please contact Kia Marie Jerichau at kmj@energinet.dk
Facts about Energinet
Energinet is Denmark’s national transmission system operator (TSO) for electricity and natural gas. It is responsible for owning, operating, and developing the country’s main electricity and gas transmission networks.
Energinet is an independent public enterprise founded in 2005 and owned by the Danish Ministry of Climate, Energy, and Utilities. With its headquarters in Fredericia, Denmark, the company employs over 1,000 staff members.
Website: en.energinet.dk
Key Responsibilities:
- Ensuring a high level of security of supply for electricity and gas
- Integrating renewable energy sources into the national grid
- Facilitating fair and equal access to the energy infrastructure
- Developing and maintaining international energy connections
- Operating the balancing markets to maintain grid stability
Notable Projects:
- Viking Link: A 1,400 MW HVDC submarine power cable connecting Denmark and the UK, enhancing energy security and renewable energy integration.
- COBRAcable: A 700 MW HVDC interconnector between Denmark and the Netherlands, improving the European transmission grid and supporting wind power integration.
- Baltic Pipe: A natural gas pipeline project enhancing gas supply security by connecting Norway, Denmark, and Poland.
Energinet plays a crucial role in Denmark’s transition to a green energy system by ensuring that the energy infrastructure supports the integration of renewable energy sources and maintains a stable and secure energy supply.
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