Caterpillar · Cat DG Series (Gas)

Cat DG150

150 kW standby · Natural Gas · Liquid-cooled

150 kW standby natural gas generator. EPA certified for demand response. No diesel storage. Bridges the gap between small gas units and the DG200.

Standby power
150 kW
Voltage options
120/208V, 277/480V
Frequency / Phase
60 Hz · 3-phase
Engine
Caterpillar DG Series Gas Engine

Overview#

The Cat DG150 is a 150 kW standby natural gas generator that fills the gap between lighter-duty gas units and the 200 kW DG200 class. For facilities that need more than a small gas genset can provide but don't require the full 200 kW output, the DG150 offers a right-sized option with all the operational advantages of natural gas.

Natural gas eliminates the diesel storage, fuel polishing, and spill containment requirements that come with diesel standby power. For commercial buildings, schools, and hospitals on gas mains, the DG150 is a simpler compliance path.

Demand response capability#

The DG150 carries U.S. EPA certification for non-emergency stationary applications. This is not a minor footnote -- it means the unit can legally run under utility demand response contracts, generating revenue during grid stress events. Diesel emergency standby generators cannot participate in most DR programs. Facilities with gas generators have an asset that pays for itself during grid events rather than sitting idle.

Applications#

The 150 kW rating is a natural fit for:

  • Commercial buildings -- mid-size offices, retail, and mixed-use facilities where full critical load is 100-150 kW
  • Schools -- emergency lighting, fire alarm, and HVAC for essential areas
  • Hospitals and medical offices -- NFPA 99 essential electrical system loads where the full facility load falls within 150 kW
  • Demand response -- utility-contracted curtailment programs requiring gas-fired generation

Our service experience#

Gas generators at this power class have straightforward maintenance profiles compared to diesel. Spark plug inspection intervals and fuel regulator calibration are the primary scheduled service items. Ensure gas supply pressure is confirmed at the generator connection point before commissioning -- low inlet pressure is a common commissioning issue on new installations that causes unstable speed at load.

Ready to order this model?

Configure your Cat DG150

Lock the enclosure, fuel system, transfer switch, and add-ons — we'll confirm pricing, availability, and lead time within one business day. Prefer a free-form quote? That option is still here.

Estimate runtime for the Cat DG150

Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.

Estimate runtime on this tank

Fuel demand at 75% load

1,575,000 BTU/hr1575.0 cf/min @ 1,000 BTU/cf

On utility natural gas the runtime is generally unlimited provided the supply line and meter can deliver this BTU/hr at the engine's required inlet pressure (typically 5–14" WC residential, up to 5 psi commercial). Confirm against the OEM's published fuel-pressure spec.

Frequently Asked Questions

What is the standby power rating of the Cat DG150?
The Cat DG150 is rated at 150 ekW emergency standby on natural gas at 60 Hz, 3-phase. Contact your local Cat dealer for demand response and prime power ratings, which differ from the standby rating.
Can the Cat DG150 participate in demand response programs?
Yes. The DG150 carries U.S. EPA certification for non-emergency stationary applications, which qualifies it for utility demand response and peak shaving programs. Diesel generators are generally restricted to emergency-only operation, making this natural gas unit a significant advantage for DR revenue.
What voltages does the Cat DG150 support?
The DG150 is available in 120/208V and 277/480V configurations at 60 Hz, 3-phase. Verify the required voltage with your electrical engineer before ordering -- voltage configuration is set at the factory.

Similar models

Caterpillar Cat DG200 200 kW liquid-cooled standby generator

Caterpillar

Cat DG200

200 kW natural gas with CAT DG200. No diesel storage needed. EPA certified for demand response. ~200 US dealers.

200 kW standby · Natural Gas / LPG · Liquid-cooled

200 kW natural gas generator with 10.3L V8 engine. Emergency standby, demand response, and prime power for commercial and industrial applications.

3-phasecommercial-standbydemand-response

Caterpillar

Cat DG175

175 kW natural gas with Cat DG175. No diesel storage. EPA certified for demand response. Ideal step between 150 kW and the 200 kW DG200.

175 kW standby · Natural Gas · Liquid-cooled

175 kW standby natural gas generator. EPA certified for demand response and commercial applications. No diesel storage or fuel management required.

3-phasestandbycommercial
Caterpillar Caterpillar G3406 300 kW liquid-cooled standby generator

Caterpillar

Caterpillar G3406

300 kW natural gas with CAT G3406 inline-6. No diesel storage needed. Legacy platform with deep parts availability.

300 kW standby · Natural Gas · Liquid-cooled

The Caterpillar G3406 is a natural gas standby generator built on the 14.6L G3406 TA inline-6 spark-ignited engine. No diesel fuel storage required. Legacy platform for hospitals, campuses, and commercial facilities.

EPA Stationary Spark Ignition3-phasecommercial-standbyhospital-medium

Need service or parts for the Cat DG150?

We service every major OEM and stock genuine parts for the most common models.