DISTRICT HEATING CONFERENCE IN AARHUS FOCUSED ON SECURITY OF SUPPLY AND BIOMASS

by Linda Bertelsen March 26, 2026

Participants gathered at ARoS in Aarhus for Fjernvarmens Branchemøde 2026, where security of supply and biomass dominated the agenda.

At Fjernvarmens Branchemøde 2026 at ARoS, two issues dominated the agenda: how to strengthen security of supply in an increasingly electrified energy system, and whether biomass should remain part of district heating’s future fuel mix. The programme also included site visits, presentations on geothermal development in Aarhus, and a closing geopolitical perspective from Lykke Friis.

Geothermal and local heat sources set the scene

This year’s industry conference in Aarhus opened with visits to Innargi’s geothermal plant and Kredsløb’s facilities, before participants gathered at ARoS for a full afternoon of presentations and debate. From the outset, the conference made clear that district heating is moving toward a more diversified setup built on several technologies rather than a single dominant source.

Innargi presented geothermal energy as a stable, local and weather-independent heat source. Its Aarhus project in Skejby delivered first heat in September 2025, and the full Aarhus development is expected to reach around 110 MW and cover 15–20% of the city’s heat demand by 2030.

Kredsløb placed geothermal in a broader system context. Its presentation showed how the future heat supply in Aarhus is being built around “the forces of nature” supported by local heat sources, with a clear emphasis on technology flexibility. One of the key messages was that the same amount of electricity can produce far more heat when used in heat pumps than in an electric boiler, especially when combined with high-value heat sources such as seawater, wastewater or geothermal energy.

Electrification offers major opportunities — but also raises new risks

The first main conference theme was security of supply, and electricity was at the centre of the discussion. Rasmus Bramstoft Pedersen from DTU highlighted the synergies of electrifying district heating: higher energy efficiency, lower system costs and better integration of renewable energy. He also underlined the role of large heat pumps and thermal storage in creating flexibility across the energy system.

At the same time, the conference did not gloss over the challenges. Electrification increases dependence on the power system, on grid expansion, on electricity prices and on market design. DTU’s presentation also pointed to a harder question: how heat should be supplied during winter peak periods when electricity production is not sufficient.

That concern was echoed in Energinet’s presentation. Morten Pindstrup pointed to the growing value of flexibility in the Danish power market, where price volatility is increasing and consumption patterns are changing. His material also showed that Denmark’s degree of self-sufficiency in the most capacity-constrained hours is expected to decline, adding weight to the broader debate about how far electrification alone can carry the heat sector.

Hobro case drew attention to resilience and self-sufficiency

One of the practical highlights was the Hobro case, which resonated strongly with participants because it moved the debate from theory to operations. The broader takeaway was clear: security of supply is not just about adding new technologies, but about building resilient systems with multiple heat sources and stronger local backup capabilities. That made self-sufficiency and operational robustness central themes in the room.

The session on gas engines added another layer to that discussion. Rather than treating them only as legacy assets, the presentation from JPH Energi pointed to their potential role in a future renewable-based district heating infrastructure, where flexible and dispatchable units may still be needed when the wider energy system is under pressure.

Biomass remained the most divisive issue of the day

If the first half of the conference focused on security of supply, the second half exposed the sharp divisions around biomass. Lars Bonderup Bjørn from EWII argued that biomass has moved from being seen as a solution to being seen as a problem, challenging its continued role in future heat supply.

Palle Madsen from InNovaSilva made the counterargument. His presentation framed forests and biomass as part of a broader portfolio approach, combining CO2 uptake, storage, material substitution and energy production. From that perspective, biomass still has a role in the district heating mix when sourced and managed sustainably.

Jannick H. Buhl from Dansk Fjernvarme took a system-wide view. His presentation showed that biomass has already played a major role in replacing fossil fuels, even though district heating is now investing overwhelmingly in electric technologies such as heat pumps and electric boilers. His key point was that biomass is likely to fill a smaller role in the future, but still remain important in a diversified supply system because it can support both security of supply and price stability.

A geopolitical close to a technical debate

Lykke Friis closed the conference by widening the lens. After a day focused on technologies, infrastructure and fuel choices, her presentation placed district heating in a broader European and geopolitical setting shaped by war, uncertainty and renewed concern about energy security. It was a fitting conclusion to a conference where supply security was discussed not only as a technical issue, but as a strategic one.

The Branchemøde 2026 was organized in cooperation with Fjernvarmens Informationsfond.