Wärtsilä’s presentation examines the use of modular gas and dual-fuel power plants alongside energy storage to supply data centers, including AI workloads. It links constraints on grid connections to growing demand for primary onsite and off-grid generation, and cites several projects in Ireland and the United States. The material emphasizes capacity availability, modularity, part-load efficiency, lower water consumption, and the potential to transition to sustainable fuels over time.
Key Takeaways
Constraints on available grid capacity and connection timelines are driving demand for onsite and off-grid generation as primary power for data centers, rather than solely as backup power.
For large AI data centers, Wärtsilä proposes scaling power plants with modular engines and pairing them with BESS to smooth load changes.
The presentation identifies delivery lead time, modularity, operating expenditure, emissions, and capacity availability as key considerations when selecting onsite generation; lifecycle service support is also material where the plant provides primary power.
The presentation cites operational or contracted data-center power projects in Ireland and the United States, demonstrating the use of gas generation at the scale of several hundred megawatts.
It argues that decarbonization should be assessed holistically by balancing commercial, operational, and ESG considerations, rather than evaluating projects solely by fuel type.
Key Figures
Projected power-capacity shortfall
40 %
Share of data centers expected to face an electricity shortfall by 2027, according to the Gartner forecast cited.
Grid-connection wait time
5–7 лет
Connection timeframe in certain markets.
Shift to onsite generation
30 %
Share of data centers expected to use onsite power as their primary source by 2030, according to the cited Bloom Energy source.
Engine power-plant module capacity
6–23 МВт
Stated output range for Wärtsilä engine power-plant modules.
Scalable power-plant capacity
500+ МВт
Stated ability to build power plants from engine modules.
Typical requirement in the historical backup-power segment
20–100 МВт
Range shown on the slide for the historical backup-power segment.
Typical requirement in the emerging off-grid segment
50–500 МВт
Range shown on the slide for emerging off-grid demand.
Irish data-center projects
170 МВт
Combined capacity of two Wärtsilä onsite data-center projects in Ireland; commercial operation is expected in 2026.
Engines in the Irish projects
17 шт.
One site includes 11 and the other 6 Wärtsilä 20V34DF dual-fuel engines.
Ohio project
282 МВт
Supply announced in July 2025 for a new data center in Ohio, United States.
Engines in the Ohio project
15 шт.
Wärtsilä 18V50SG gas engines in the onsite power plant for the data center.
Order for a US data center
507 МВт
Order announced in November 2025 for an onsite gas power plant for a new data center in the United States.
Engines in the 507 MW project
27 шт.
Number of Wärtsilä 50SG engines in the US data-center project.
Project serving US data-center demand
429 МВт
Power-plant capacity using 24 Wärtsilä 50SG engines; supplier selection was announced in January 2026.
Commissioning of the 429 MW project
конец 2028 — начало 2029
Expected start of commercial operations for the power plant serving a major US data-center development.
Practical Value for Data Center Owners
For data-center owners and project teams, the material provides a reference point for situations in which a grid connection cannot be secured within the required timeframe: an onsite microgrid based on modular gas or dual-fuel engines and BESS can be considered as a primary power source across the indicated scale range and beyond. At the concept stage, teams should separately compare capital expenditure, time to commissioning, fuel infrastructure, emissions and water requirements, the AI-load profile, redundancy needed for high availability, and the potential to transition to alternative fuels.
The paper introduces FissionReady, a scheduler for data centers supplied by a multi-module small modular reactor (SMR) plant. It jointly manages the output of each reactor module, deferrable batch workloads, and grid purchases while accounting for fuel age, iodine-xenon dynamics, and reactivity margin. In simulations, the approach eliminates forced outages and missed batch-job deadlines while reducing water use and grid-electricity costs relative to a comparable baseline configuration.
Small Modular Reactors (SMRs)Data Center Power SupplyGeneration Load FollowingData Center Microgrids
This AVK and Wärtsilä Energy white paper examines constrained grid capacity as a major barrier to the expansion of European data centres, particularly facilities serving AI workloads. It proposes on-site microgrids combining dispatchable generation, BESS and renewables to accelerate site energisation before—or independently of—a grid connection. The paper compares power-system scenarios and four supply configurations for a representative AI data centre in terms of cost, reliability, land use and carbon footprint.
Data Centre Power SupplyAI Data CentresMicrogridsDispatchable Generation
This Cummins white paper examines the shift in data center onsite power systems from traditional emergency backup toward an active-standby model. It identifies decarbonization and shortages of grid capacity and transmission capability—particularly acute in Europe and North America—as the key drivers. The paper considers cleaner fuels and generation technologies, energy storage, fuel cells, and microgrid controls that could enable data centers to support the grid without moving to continuous onsite generation.
Data Center Power SupplyOnsite GenerationActive StandbyGrid Constraints