Best Generators for Data Centers in 2025

Tier I: Basic capacity with a single path for power, no redundancy. 99.671% uptime.

Tier II: Redundant capacity components (N+1 generators). 99.741% uptime.

Tier III: Concurrently maintainable with multiple power paths and N+1 redundancy. 99.982% uptime. This is the most common standard for enterprise data centers.

Tier IV: Fault tolerant with 2N or 2(N+1) redundancy across all components. 99.995% uptime. Required for financial services, government, and critical infrastructure.

Diesel remains the dominant fuel for data center generators because it starts reliably in under 10 seconds, offers high power density, and requires minimal infrastructure beyond fuel storage tanks. Most Tier III and IV facilities standardize on diesel.

Natural gas is emerging as a cleaner alternative, especially for edge and Tier II facilities with utility gas service. Natural gas generators produce lower emissions and can run indefinitely without fuel delivery. However, gas pipeline disruptions during major events can be a concern.

Cummins Power Generation is the industry leader for data center power, with generators from 200 kW to 3,250 kW featuring PowerCommand® paralleling controls and seamless integration with building management systems.

Kohler offers the KD Series for data centers with advanced Decision-Maker® 3500 controllers, delivering precise voltage and frequency regulation critical for sensitive IT equipment.

Generac Industrial provides competitive diesel and gas options for edge data centers and smaller facilities, with remote monitoring via Mobile Link™.