On-site Power Generation for Data Centers: How Gas Turbines Deliver Maximum Availability

About This Document

This Siemens Gas and Power white paper examines on-site generation of electricity and cooling for data centers as an alternative to reliance on a constrained or unreliable external grid. Its main focus is on modular gas-turbine solutions, including open-cycle and combined-cycle configurations, combined heat and power (CHP) with absorption cooling, redundancy, and operational lifecycle considerations. The paper also outlines approaches to planning, EPC delivery, service, and decarbonization through biofuels and hydrogen.

Key Takeaways

• Growing data-center capacity and grid instability or constraints make the quality and availability of external power supply a strategic risk; on-site generation is considered a primary source of power, rather than solely an emergency source.
• A modular, multi-unit gas-turbine configuration is preferable for data centers, as it enables capacity redundancy, phased deployment, and continued operation while one unit is under maintenance.
• The choice of topology depends on site constraints, climate, gas prices, electricity tariffs, and cooling demand: open cycle prioritizes compactness; combined cycle prioritizes electrical efficiency; and CHP with an absorption chiller prioritizes overall fuel utilization.
• The redundancy mode directly determines UPS requirements: cold standby must cover generator start-up time, while hot standby and BESS reduce the gap following a generation failure.
• The paper links its decarbonization pathway to improved efficiency, the use of biofuels, and the conversion of gas turbines to hydrogen; however, environmental and economic parameters must be assessed for each specific site.

Key Figures

Minimum required data center availability

99.671 %

For data centers storing mission-critical data 24/7.

Potential share of global electricity consumption by data centers and associated networks

51 %

Estimate for 2030, cited in the document with reference to an external source.

Connected digital devices

50 billion devices

Forecast used to illustrate the growth of digitalization.

Volume of data generated

40 zettabytes

Estimate associated with 50 billion IP-connected devices.

Initial data center capacity for phased scaling

20 or 50 MW

Example of an initial scale that can be expanded modularly.

Open-cycle electrical efficiency

33–43 %

Typical range for open-cycle gas-turbine generation.

Combined-cycle electrical efficiency

48–58 %

Typical range for combined-cycle operation.

Maximum combined-cycle electrical efficiency

up to 63 and more %

Stated achievable level for combined-cycle operation.

Additional increase in combined-cycle electrical efficiency

more than 15 %

Through the use of gas-turbine waste heat to produce steam.

Electrical efficiency of CHP with absorption cooling

33 %

Configuration with a gas turbine, HRSG, and absorption chiller.

Fuel utilization of CHP with cooling

75–85 %

Typical level for a cogeneration configuration with cooling.

Ambient temperature for applying CHP with cooling

more than 30 °C

Scenario for hot regions.

Electrical efficiency of a combined-cycle and CHP combination

up to 58 %

At low additional cooling demand.

Total fuel utilization of a combined-cycle and CHP combination

up to 85 %

For an integrated power-generation and heat-recovery configuration.

Start-up of backup turbine unit

less than 20 minutes

For a stationary backup unit in the event of an unplanned failure of one turbine package.

Start-up of fast-start turbine type

less than 5 minutes

For fast-start turbine types.

Cold-standby start-up

15 minutes

The interval must be covered by the UPS under the cold stand-by configuration.

Hot-standby response to full load

less than 10 seconds

N+1 configuration.

BESS start-up time

less than 1 seconds

The energy storage system compensates for the loss of generation.

Gas-turbine readiness to operate on pure hydrogen

100 % H₂

Target stated in the document for 2030.

Practical Value for Data Center Owners

For a data-center owner or project team, this provides an initial set of architectural scenarios for a preliminary comparison of on-site generation with grid supply: open cycle where land is scarce and capacity is the priority; combined cycle where electrical efficiency is the priority; and CHP with an absorption chiller where cooling demand is high. The document is useful for defining requirements for N+1/N+2 redundancy, UPS/BESS autonomy time, gas and water availability, emissions, and service strategy. The supplier's economic claims require separate site-specific validation covering CAPEX, gas and electricity tariffs, grid connection, and permitting requirements.

Where It Applies

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