How Vaasa’s district heating keeps the city warm

Today, around 70-75% of Vaasa’s residents live in buildings heated by district heating. This means that most of the city is part of one shared energy system. A common network brings efficiency, cost savings, energy security, and the ability to continuously improve how heat is produced and delivered.

From production to your home

Everything starts with heat production. In Vaasa, heat is generated in several ways:

• combined heat and power production
• electric boilers
• recovering waste heat
• utilising energy from waste

At the production plant, water is heated and pumped through an underground district heating network to buildings across the city. Inside each building, a heat distribution unit transfers the heat into the building’s own heating system. This heat is then used in many ways: warming radiators, underfloor heating, and household hot water.

Once the water has delivered its heat, it flows back to the production plant to be reheated and reused again and again. The entire system is carefully controlled behind the scenes to ensure heat is produced and distributed as efficiently as possible.

Affordable and sustainable

District heating in Vaasa is among the most affordable in Finland. Long-term development, starting in the 1960s, has made the system both cost-efficient and reliable.

Since the 2010s, heat production has been steadily moving away from fossil fuels towards renewable and electrified solutions. Today, around 30% of heat is produced without combustion, using electric boilers and heat pumps – and this share continues to grow.

Additional environmental benefits come from recovering heat from wastewater. This alone is enough to heat approximately 2,000 detached houses while helping keep costs at a reasonable level.

Storing heat for when it’s needed

In Vaskiluoto, Vaasa has a large heat storage facility with a capacity of around 17 gigawatt hours after its expansion. When fully charged, it could keep the city warm for up to ten days in mild winter conditions without any new heat production.

This storage makes it possible to produce heat at the right time. Heat is generated when electricity is affordable and wind power is abundant, and the stored energy is used when production is lower or prices rise. This improves cost efficiency and adds stability to the entire energy system.

Data and AI behind the scenes

The district heating network is continuously managed using real-time data. Temperatures, flow rates, and pressure levels are monitored throughout the system, and sensors can detect even small leaks at an early stage. This allows for quick repairs and helps limit disruptions to smaller areas.

At the heat pump plant, artificial intelligence is used to forecast wastewater flows and the amount of heat that can be recovered from them hour by hour. The system also learns everyday patterns, such as weekends and holidays. Together with weather forecasts and electricity market data, this information helps optimise heat production.

In the control room, the system is monitored around the clock. When everything runs smoothly, operations are largely automated. If something unexpected happens, it is addressed quickly and often without customers noticing anything at all.

Part of a wider European energy system

Vaasa’s district heating system is part of a much larger energy network. Through electric boilers and combined heat and power production, it is connected to the electricity market and, through that, to the wider Nordic and European energy system.

Production decisions are influenced by electricity price forecasts, cross-border transmission capacity, the availability of wind power, and market conditions elsewhere in Europe. Local energy solutions are part of an interconnected system where everything affects everything.

Based on interviews with Henri Torsti and Lauri Mettiäinen (6 February 2026).

Written by Sanni Mullo