Wärtsilä has put a number on a question the data center business is arguing about: what should supply a campus that cannot wait for the grid. In a press release on 2 November the Finnish engine maker presented a study that compares flexible engine plants with combined-cycle gas turbine plants for off-grid data centers, and concludes that engines could save up to EUR 200 billion over twenty years.
What The Company Compared
The study scales up an earlier Wärtsilä paper on single projects. It starts from a scenario in which off-grid data center capacity worldwide reaches 55 GW by 2035, which the company itself calls the upper end of the outlook and not a forecast. For that case it puts the saving at about EUR 196 billion, and it ties the figure to suitable grid and market arrangements. The scenario is built on third-party forecasts, including those of BloombergNEF, and on a review of announced projects and where they stand in permitting.
The reasoning behind the cost gap is that engine plants need less generating equipment and less battery storage to cover the same demand, because they can follow a changing load. Wärtsilä adds two side effects: far less cooling water, a reduction it puts at nearly 100 percent, and a much smaller site. It also points to the heat from the engines, which could feed district heating networks where a network is within reach.
A Supplier Making Its Own Case
This is a study by a company that sells the engines, and Wärtsilä says so openly by describing its technology scenarios as illustrative. It also expects real projects to use a mix of technologies. Readers should take the billions as a direction of argument, not as a quote for a project.
The more useful part is the point about what happens after the grid arrives. A plant built to bridge a connection queue can later give backup power and help balance wind and solar, if the market lets it earn from that. Wärtsilä asks developers, regulators and grid operators to settle that question early.
For people who plan sites, the practical side is familiar. A plant that runs most hours of the year has a different heat and cooling picture from a standby plant, and the water and land questions are decided in the first drawings. More on this is on our data centers and power plants pages.
Sources: Wärtsilä
