Used industrial generators for sale, 100 kW to 3 MW

Used, surplus and reconditioned, what each one means

A used generator set has run in service and is sold as it stands, with whatever hours are on the meter. A surplus unit was bought for a project and never installed, or barely run, so it behaves like new stock at a used price. A reconditioned unit has been inspected and repaired, often with fresh fluids, filters, batteries and a load bank test, and costs more than the same unit sold as is.

Ask which of the three you are being offered, because sellers use the words loosely. The two numbers that matter most are the hours on a non resettable meter and the result of a recent load bank test at full rated load.

Used generator prices by size

These are public dealer figures, not our prices. Hours, controls, enclosure, emissions tier and whether switchgear comes with the set move a used price more than the badge does.

Asking prices from dealer guides, read November 2026. Asking prices are not sold prices.

Generator sizes, kVA and full load amps

Generator sets are usually rated in kW at a power factor of 0.8, so the kVA is the kW divided by 0.8. The amps below are computed from that kVA. Use them to check the breaker, the transfer switch and the cable on the job before you choose a unit.

Computed. Amps equal kVA times 1,000 divided by the square root of 3 times the voltage.

Standby, prime and continuous ratings

The same engine carries different kW figures depending on the duty. ISO 8528 sets three, and a used set has to be bought on the rating that matches how you will run it. A standby set that has been run as a prime power plant has worked beyond its rating, which is exactly the history you do not want to buy.

Emissions tier, the rule that decides where a used set can go

In the US, diesel generator sets above about 120 to 125 kW became subject to EPA Tier 4 from the start of 2011. Emergency units, whose only job is backup power when the utility fails, were allowed to stay at the earlier Tier 2 or Tier 3 level. Non emergency units, including sets used for prime power, peak shaving, rental or mobile work, have to meet Tier 4.

An emergency unit can run without limit during an outage, but maintenance and exercise are capped at 100 hours a year, and only 50 of those can be general non emergency running, never peak shaving or selling power. The running time has to be logged against a non resettable hour meter. Run it outside those limits and the engine can be treated as non emergency, which brings Tier 4 with it. California and other areas with poor air quality can be stricter.

So a used Tier 2 set is a sensible buy for standby at a hospital, a plant or a data center, and the wrong buy for running a site every day. Tell us the duty and we will only offer units that fit it.

What to check before you buy a used generator

Ask for all of the following in writing. A seller who cannot produce them is selling you a guess.

• Hours on a non resettable meter, with a photograph
• A recent load bank test report at full rated load, with voltage, frequency and coolant temperature logged
• Engine and generator serial numbers and the set nameplate, so the rating and voltage can be confirmed
• The emissions tier and the EPA label, and whether the engine is certified for emergency use only
• Oil and coolant analysis if the seller has it, and the service history
• Controller make and model, and whether it can parallel or work with your transfer switch
• Enclosure type, sound level and the fuel tank size and runtime
• Proof of ownership and a clear title, especially for trailer mounted units

New versus used lead times

New large diesel sets are slow because data centers are buying them in volume. Power magazine reports lead times of up to a year or more for larger data center packages. Cummins has been expanding a plant to tackle 18 month lead times on high horsepower units, according to MarketsandMarkets. Caterpillar reported a record order backlog of 63 billion dollars in 2026, with data centers a major driver.

A used or surplus set that already exists can usually ship as soon as it is tested and paid for, so the real wait is the load bank test, any repairs and the freight.

Shipping and setting a used generator

A large set with its enclosure is heavy freight set with a crane. Ask for the shipping weight and dimensions with the quote, confirm the pad and the crane access before it leaves the yard, and plan the transfer switch and the cabling at the same time, since those often take longer than the set itself.

How much does a used 1,000 kW generator cost

One 2026 dealer guide puts a used Kohler KD1100, a 1,000 kW diesel set, at about $88,000 to $155,000, and major brand diesel sets from 250 to 1,000 kW at $35,000 to $165,000. Hours, the emissions tier, the controller and whether switchgear comes with it decide where a unit sits in that range.

How many hours is too many on a used generator

There is no single number, because a set run at a steady load is in better shape than one that has been started cold and run lightly for years. A standby set typically runs about 200 hours a year, so a 15 year old standby unit with a few thousand hours is normal. What matters more than the hours is a clean load bank test at full rated load and a service history.

Can I use a used Tier 2 generator

Yes, for emergency standby, where the set only runs during utility outages plus limited maintenance and exercise time, capped at 100 hours a year. For prime power, peak shaving or rental, a diesel set above about 125 kW has to meet Tier 4, and local air rules can be stricter.

What is the difference between standby and prime power

Standby is the rating for backup power during an outage with a variable load and limited hours each year. Prime is the rating for running as the main power source with no limit on yearly hours. The prime kW figure on the same set is lower than the standby figure.

Do you sell generator sets with a transformer

Yes. A generator feeding a medium voltage system needs a step up transformer, and we quote the set, the transformer and the transfer or paralleling gear on one delivered quote.