Until 2024 MerikarviaThe district heating in the city centre was produced using waste heat from Metsä Fibre's sawmill. When the sawmill ceased operations in August, heat production had to be supplied using light fuel oil, which significantly increased energy costs. MerikarviaThe municipality was facing a new challenge – a sustainable and cost-effective energy solution was needed.
Merikarvian In early 2025, Lämpö and the municipality participated in a seminar where various energy production options were discussed. There, interest in the data center was aroused – and at the same time, a connection was made with Vatajankoski, which offered an optimized solution precisely Merikarvian. In April 2025, an agreement was signed to build a 1,5 megawatt data center on the site of an old sawmill. After a rapidly progressing construction phase, the data center was commissioned on June 23, 2025 and began producing district heating without combustion.
The data center, built by Vatajankoski and E-Heat, utilizes the heat from the cooling water of the data servers. This heat is fed directly into the district heating network, which reduces carbon dioxide emissions and improves energy efficiency. According to calculations, the data center's waste heat can cover 90–95% of the Merikarvian district heating needs – the final share depends on the coldness of the winter.
"After the data center is started Merikarvia"The oil heating plants have been closed, and oil trucks have no longer been seen on the road. The longer the autumn progresses without the use of oil, the greater the savings will be for both the company and its customers."
Tiina Holma, CEO, Merikarvian Heat
The rest of the district heating is currently produced with oil, but there are plans to start developing an alternative, renewable energy solution, such as solar energy. The goal is that in the future, all district heating production would be based on unburned energy, leaving light fuel oil only for backup use.
The data center supports regional vitality and new industry
The data center has made the old sawmill area more attractive to businesses. The area has space and a large enough electrical connection ready, which allows for quick relocation. The goal is for the area to attract businesses that can utilize the heat generated by the data center in the summer.
“We now have the starting points that make the area attractive for new businesses.”
Tiina Holma, CEO, Merikarvian Heat
Merikarviamayor Juha Vasama has heard mostly positive feedback from local residents about the data center. “Most people see the solution as sensible and forward-looking. The project has also attracted interest nationwide,” Juha says.
Successful cooperation enabled rapid implementation
The speed and efficiency of the project were a positive surprise. The lease agreement was approved at the end of March, and the data center was operational by July. The work progressed on a fast schedule, made possible by smooth cooperation between the project parties.
"The collaboration has been smooth and fast. We had just the right amount of people involved and everything has gone smoothly."
Juha Vasama, Merikarviamayor
What was achieved with the data center
- 90–95% of the district heating needs are covered by waste heat – the final share depends on the coldness of the winter
- The heating plants have been closed since the data center started up, and oil trucks have no longer been seen on the road.
- Clear savings for both the company and customers. In November 2025, customers will receive a 25% price reduction
- Fast implementation – agreement in April, production underway after Midsummer
- Possibility of new industrial expansion in the area
The role of Vatajankoski in the project
- Area plot rental
- Data center implementation together with E-Heat (E-Heat owns the data servers and is responsible for their operation)
- Data center construction (foundations and piping)
- Heat recovery and delivery Merikarvian For heat