Kall vinterdag i Luleå

Lower prices on cold winter days

Swerim is helping to gain an overall understanding of the district heating system in Luleå from a broad perspective. This is part of a collaborative effort between LuleKraft and Luleå Energi, the aim of which is to reduce environmental impact and costs.

LuleKraft's cogeneration plant produces both heat, which is sold to district heating company Luleå Energi, and electricity. Production is controlled by several factors; for example, weather, fuel prices and heating demand from customers.

Holistic perspective

To increase revenue, it may in some circumstances be best to increase power production. But if power production is increased, then heat production must decrease and heat must therefore be produced by other plants using other fuels. Even if increased power production yields higher returns and is the best strategy in that respect, it may not be optimal in a broader sense. Process integration is a way of improving production systems by adopting a holistic perspective, instead of merely focusing on the individual processes.

Cost efficient and environmental gains

Currently, a process integration survey of Lulea’s district heating system is being conducted and Swerim, LuleKraft and Luleå Energi have developed a systems model. Work has resulted in a better understanding of cost-effective and environmentally sound production, as well as pointing to the need for close collaboration among the companies involved. A comparison of production data revealed that there is potential for savings of up to SEK 300,000 on cold winter days.

Lulea’s district heating network is 400 km long and serves 31,000 households and several large industrial and commercial customers. The district heating system has five production units which run on process gases from SSAB, wood pellets, electricity and oil. About half or 2000 GWh, of all process gas from SSAB's integrated steel production is used to produce district heat, electricity and process steam.