In the city of Lund, in southern Sweden, a remarkable transformation towards climate neutrality has been unfolding. With a population close to 128 000 inhabitants, Lund has embarked on the ambitious mission of reducing its carbon footprint and pave the way for a sustainable future.
In 2010, Lund took a significant step by committing to become a climate-neutral and fossil fuel-free city by 2030. The city's sustainability policy outlines ambitious targets, aiming to reduce greenhouse gas emissions by at least 65 percent by 2025 and 80 percent by 2030, in comparison to 2010 when they started measuring emissions.
To achieve these goals, Lund has adopted critical measures in its heating system, which started back in the 1950s.
A biomass-fired combined heat and power plant
Traditionally relying on oil, natural gas, and geothermal sources for district heating, the city sought innovative solutions. The turning point came with the establishment of a combined biomass-fired heat and power plant in 2015, which provided not only sustainable heating but also generated electricity. This decision allowed Lund to phase out natural gas and decrease its dependence on imported electricity.
Operated by the city’s power company, Kraftringen, district heating accounts today for 90% of the city’s heat demand.
Low-temperature district heating
Through the COOL DH project, Lund is now focusing on low-temperature district heating, and has built the largest low-temperature district heating network in the world. This approach, suitable for well-isolated new buildings, allows Lund to lower the temperature of the district heating, reducing energy losses.
Waste heat, which is too cold for traditional district heating, can be utilised in these systems. Lund harnesses waste heat from the Lund University research facility Max IV.
Low temperature district heating has lower investment costs than traditional district heating. For cities that do not have DH available yet, opting for a low temperature grid can be faster and cheaper, as they can be installed with plastic pipes instead of steel pipes, allowing to skip several steps of development.
The project started in 2019 and is currently under development. The solution is being built in the Brunnshög district of Lund, which aims to house and employ 40,000 people by 2050.
What were the key drivers supporting the implementation?
- Political stability, regardless of political affiliations, was one of the main factors that enabled the development of these projects.
- The involvement of different municipal departments through a cross-sectoral working group has been instrumental in Lund's climate neutrality journey.
- With regard to the construction of the biomass plant, the partial ownership of the municipality helped to secure the necessary loans for the significant investment required.
- The existing customer of the power company base played a role in supporting the projects.
- The technical feasibility of the district heating solution was a key driver for implementation.
And which were the challenges and barriers the city encountered?
- Ensuring an adequate feedstock supply for biomass could become a challenge in some cases. However, Lund managed to secure a close supply than initially expected.
- The significant investment required and other economic factors, particularly for cities without district heating, can be a major barrier.
- However, for cities where district heating is not available yet, it is easier and cheaper to start with low temperature grids.
Potential for replication of the biomass-fired power plant:
Building on the success of the first plant, Lund is now gearing up for a second combined biomass-fired power plant. This upscaled facility will not only enhance efficiency by replacing smaller plants, but also benefit local industries, like the sugar factory, by reducing their natural gas consumption. The decision to upscale was driven by both Lund’s climate commitment and the plant's profitability for the power company.
The initiative has already been replicated in several Swedish cities. In fact, such solutions are so advanced in the Scandinavian country that they are not even considered innovative.
Potential for replication of the low-temperature district heating project
The COOL DH project was co-developed with their sister pilot in the Danish city of Høje-Taastrup, which utilises waste heat from data centres and shopping malls. At the same time, Lund is already planning to replicate it in a nearby village of 2,000 inhabitants.
Therefore, both projects have potential for replicability across Europe. Some of the limitations may come from technical (availability of heat sources and infrastructure), financial, and logistical considerations.