EPV Energy is building its second balancing power plant in Finland, and again the machines are gas engines. Wärtsilä announced on 12 November that it will deliver a 43 MW plant at the existing Mertaniemi power plant site in Lappeenranta under a full engineering, procurement and construction contract, together with a six-year service agreement. The order was booked in the fourth quarter of 2026, and the plant is to be fully operational in the first half of 2029.
Four 34SG Engines At Mertaniemi
According to the announcement, which POWER magazine carried as a contribution from Wärtsilä, the plant will have four Wärtsilä 34SG engines. They start on natural gas. The design allows a move to lower-carbon fuels, and biogas and synthetic renewable gases are to be brought in step by step as enough of them becomes available. The job is described plainly: supply power in demand peaks, during disturbances in the system and in the hours when wind and solar do not deliver. The engines can start and stop quickly, the company says. It gives no start time and no efficiency figure.
The service agreement runs through the Wärtsilä Expertise Centre and covers maintenance planning and coordination, operational support and predictive maintenance based on digital analytics. Gas to Power Journal reported the order the same day and calls the unit a fast-ramp plant.
Mertaniemi was picked for a practical reason. EPV's own project page says the existing infrastructure there allows faster development, and that the company had a preliminary agreement with the local utility Lappeenrannan Energia on developing the project. During permitting EPV spoke of several gas engines with 40 to 45 MW in total. Arto Nikkanen, chief executive of Lappeenrannan Energia, says the investment builds on what is already on the site.
Tornio Came First, Kotka And Oripää Are On The List
The first plant of the programme stands in Tornio. It also has 43 MW, is operated by EPV's subsidiary Tornion Voima and went into operation in April 2026, likewise with Wärtsilä gas engines and a service agreement. EPV describes it as Finland's first modern engine power plant.
Two more sites are in preparation according to EPV's programme page. In Kotka, at Mussalo, the company is developing a plant of about 40 to 45 MW and has a preliminary lease agreement with the city. In Oripää it has signed a letter of intent with Wega Group for a plant of 40 to 50 MW next to a circular economy facility, which would run on liquefied bio-methane and e-methane.
EPV's chief executive Rami Vuola gives the reasoning: generation depends more and more on the weather while demand grows, so flexibility becomes a basic requirement of the power system. For Wärtsilä it is a small contract next to the data center orders in its order book, and a second one from the same customer for the same kind of plant.
A Plant That Stands Still Most Of The Year
A balancing plant earns its money in a few hundred starts, not in thousands of running hours. That turns the usual priorities of an engine power plant around. What counts is that four engines which have stood for days come up to load within minutes on a January night in south-east Finland, and do the same on a still, warm afternoon in July.
For the auxiliaries this is the harder duty. The cooling circuits have to be kept warm and safe from frost while nothing runs, then carry the full heat of the engines shortly after the start signal, and the fans have to follow a load that goes from zero to full and back several times a day. In an enquiry for such a plant the two figures we look for first are the number of starts per year and the lowest temperature the site has to start from. Both are often missing.
Sources: POWER magazine (Wärtsilä announcement), Gas to Power Journal, EPV Energy (balancing power programme), EPV Energy (Lappeenranta project)
