Wärtsilä has taken another order to generate power directly at a data center in the United States. The company announced on 5 October that it will supply 15 of its 50SG gas engines, 282 MW in total, to a large U.S. independent power producer building the plant for a new data center. Neither the customer nor the site has been named. The order went into Wärtsilä's books in the third quarter; the engines are due for delivery in 2028 and the plant is expected to be in full operation in 2029.
By Wärtsilä's count this is its seventh data center order in the U.S., and the engine capacity it has sold to U.S. data centers has now passed 3 GW.
Why The Plant Sits At The Data Center
The reasons given are the ones developers have repeated all year: transmission bottlenecks, long queues for a grid connection and electricity demand that keeps rising with AI workloads. Risto Paldanius, who heads Wärtsilä Energy in the Americas, said in the announcement that traditional energy infrastructure is not keeping pace with the growth of the U.S. data center market, and described flexible onsite generation as a way for developers to reduce deployment risk.
The release does not say whether the engines will carry the campus around the clock or run alongside a grid supply. A plant made of fifteen units can do either. Engines can be started and stopped in steps to follow the load, and one unit can be down for maintenance while the others keep the campus supplied.
Closed-Loop Cooling
One line in the announcement is worth a second look for anyone who plans such a site: Wärtsilä states that the engines use a closed-loop cooling system with minimal water consumption. Data center projects already face hard questions about water from authorities and neighbours, and an engine plant that evaporated water for cooling would add to them.
In a closed loop, the heat from the jacket water and the charge air is pumped to air-cooled radiators and released to the atmosphere, and the coolant stays in the circuit. The price is space and fan power. A row of large gas engines rejects a great deal of heat, and the radiators that handle it have to be laid out so that warm discharge air does not drift back into the inlets of the units next to them. It is the hottest days at the site, not the annual average, that decide whether the plant keeps its rating. On a campus where engine power plants and data center cooling share the same ground, that becomes one layout question rather than two.
Fuel Later
Wärtsilä also says the engines can be converted to future fuels. It has not said which fuel or when, and the plant is announced as a gas plant. The engines, their auxiliaries and the cooling circuits will stay in place for decades; the fuel may not.
Sources: Wärtsilä, Pipeline & Gas Journal
