Generac builds more than 70 industrial stationary generators between 20kW and 3.25MW, in diesel and natural gas. In 2026, a new Generac industrial unit costs roughly $12,000 to $22,000 for a 20kW diesel, $150,000 to $225,000 for a 500kW diesel, and $275,000 to $375,000 for a 1MW diesel, before installation. Natural gas models cost more than diesel at the same rating. Factory orders take 30 to 36 weeks. Stocked new, new surplus, and used Generac units can ship in days.
Generac’s website lists the engine, the enclosure, and the fuel options for every industrial generator it builds. It doesn’t list a price, and it doesn’t say how long you’ll wait for one.
Those are usually the first two questions a facility manager asks. This guide answers both, model by model, across Generac’s full industrial lineup.
How to Read a Generac Model Number
A Generac industrial model number tells you three things: whether the unit stands alone or parallels, what fuel it burns, and its standby kW rating.
- First letter: S is a single, standalone unit. M is a modular unit built to parallel with other Generac generators.
- Second letter: D is diesel. G is gaseous, meaning natural gas or propane.
- The number: standby kW rating. An SD500 is a 500kW single diesel unit. An MG350 is a 350kW modular gas unit.
- SDMD prefix: used on diesel platforms of 900kW and up, which come in both single and paralleling versions.
- -4 or -T4 suffix: Tier 4 Final emissions, for non-emergency and prime power applications.
- Displacement suffix: some sizes come on more than one engine. The SG150 runs an 8.8L engine, while the SG150_14_2 uses a 14.2L block.
An M unit costs more than the matching S unit because it carries paralleling controls. The payoff is flexibility. A site can install two 500kW sets instead of one 1MW set, add capacity later, and service one unit while the other carries the load.
Generac Industrial Generator Prices by Model
Generac doesn’t publish prices for its industrial line. Every new unit is quoted through the distributor assigned to your territory. The estimates below are built from published 2026 industry pricing for new generators from major manufacturers, applied to each Generac model’s kW rating.
Estimates cover the generator set only, with a standard weather or sound attenuated enclosure, EPA-certified for emergency standby. MD and MG paralleling versions run higher than the SD and SG prices shown.
| kW | Diesel models | Est. new price (diesel) | Gas models | Est. new price (gas) |
|---|---|---|---|---|
| 20kW | SD020 | $12,000 to $22,000 | – | – |
| 25kW | SD025 | $14,000 to $26,000 | – | – |
| 30kW | SD030 | $16,000 to $29,000 | – | – |
| 35kW | SD035 | $18,000 to $32,000 | SG035 | $21,000 to $37,000 |
| 40kW | SD040 | $20,000 to $35,000 | SG040 | $23,000 to $41,000 |
| 45kW | – | – | SG045 | $25,000 to $44,000 |
| 50kW | SD050 | $23,000 to $41,000 | SG050 | $26,000 to $47,000 |
| 60kW | SD060 | $26,000 to $46,000 | SG060 | $30,000 to $52,000 |
| 70kW | – | – | SG070 | $33,000 to $57,000 |
| 80kW | SD080 | $31,000 to $54,000 | SG080 | $35,000 to $62,000 |
| 100kW | SD100 | $35,000 to $60,000 | SG100 | $40,000 to $69,000 |
| 130kW | SD130 | $44,000 to $75,000 | SG130 | $51,000 to $86,000 |
| 150kW | SD150 | $51,000 to $84,000 | SG150, MG150 | $58,000 to $97,000 |
| 175kW | SD175 | $58,000 to $96,000 | SG175 | $67,000 to $110,000 |
| 200kW | SD200 | $66,000 to $107,000 | SG200, MG200 | $76,000 to $123,000 |
| 230kW | SD230 | $75,000 to $120,000 | SG230 | $86,000 to $138,000 |
| 250kW | SD250 | $80,000 to $129,000 | SG250, MG250 | $92,000 to $148,000 |
| 275kW | SD275 | $88,000 to $139,000 | SG275 | $101,000 to $160,000 |
| 300kW | SD300, MD300 | $95,000 to $149,000 | SG300, MG300 | $109,000 to $172,000 |
| 350kW | – | – | SG350, MG350 | $125,000 to $195,000 |
| 400kW | SD400, MD400 | $123,000 to $188,000 | SG400, MG400 | $141,000 to $217,000 |
| 450kW | – | – | SG450, MG450 | $157,000 to $238,000 |
| 500kW | SD500, MD500 | $150,000 to $225,000 | SG500, MG500 | $172,000 to $259,000 |
| 600kW | SD600, MD600 | $176,000 to $258,000 | – | – |
| 625kW | – | – | SG625, MG625 | $210,000 to $306,000 |
| 750kW | SD750, MD750 | $214,000 to $305,000 | SG750, MG750 | $246,000 to $350,000 |
| 900kW | SDMD900 | $251,000 to $348,000 | – | – |
| 1,000kW | SDMD1000 | $275,000 to $375,000 | SG1000 | $316,000 to $431,000 |
| 1,250kW | SD1250, MD1250 | $350,000+ (quote) | – | – |
| 1,500kW | SD1500 | $420,000+ (quote) | – | – |
| 2,250kW | SDMD2250 | Project quote | – | – |
| 2,500kW | SDMD2500 | Project quote | – | – |
| 2,750kW | SDMD2750 | Project quote | – | – |
| 3,000kW | SDMD3000 | Project quote | – | – |
| 3,250kW | SDMD3250 | Project quote | – | – |
What moves the final number:
- Size: price per kW drops as units get bigger. Units under 50kW run roughly $600 to $1,100 per kW. Most equipment between 100kW and 2MW lands around $300 to $450 per kW.
- Scale: doubling the kW doesn’t double the price. Going from 500kW to 1MW typically adds 60% to 80%.
- Fuel: gas costs more than diesel at the same rating, and the gap widens with size.
- Emissions: Tier 4 Final adds roughly 40% to 50%. Most emergency standby sites don’t need it.
- Enclosure: upgraded sound attenuation adds 15% to 40% over an open skid.
- Configuration: voltage, fuel tank size, controller options, and paralleling gear all change the quote.
Installation, transfer switches, and site prep are separate. For those numbers, see Generac generator cost including installation.
What Used Generac Generators Cost
A used Generac industrial generator typically sells for 20% to 35% of its new price. Age, hours, enclosure, and maintenance history drive where a specific unit lands.
Two examples from Generator Source’s current inventory:
- A 2001 Generac 600kW diesel with 828 hours, listed at $28,000
- A 1998 Generac 2000kW diesel with 58 hours, listed at $120,000
For emergency standby, older Tier 2 and Tier 3 generators generally remain legal to install and operate. That’s why a used SD500 or SD600 is often the fastest and least expensive route to code-compliant backup power. Every used unit Generator Source sells goes through a 31-point inspection and a load bank test before it ships.
The Full Generac Industrial Lineup by Size
20kW to 30kW Small Diesel Generators
Generac’s smallest industrial diesels run on a 2.2L engine and fit sites with modest, critical loads.
- Models: SD020, SD025, SD030
- Typical sites: telecom shelters, small lift stations, remote equipment pads, light commercial buildings
35kW to 80kW Light Commercial Generators
This range is where Generac’s natural gas depth starts, with seven gas models against five diesels.
- Diesel: SD035, SD040, SD050 (3.3L), SD060, SD080 (4.5L)
- Gaseous: SG035, SG040, SG045, SG050, SG060, SG070, SG080 (4.5L)
- Typical sites: retail, clinics, restaurants, small offices, pump stations
For a site that already has natural gas service, a gas unit usually means no fuel tank, no fuel polishing, and no refueling contract.
100kW to 175kW Commercial Generators
This is the middle of the commercial market, with 6.7L diesels and gas units on two engine sizes.
- Diesel: SD100, SD130, SD150, SD175 (6.7L), plus Tier 4 Final versions of each
- Gaseous: SG100, SG130, SG150 (8.8L), SG150_14_2, MG150_14_2, SG175 (14.2L)
- Typical sites: mid-size manufacturing, schools, grocery, multi-tenant commercial
200kW to 300kW Generators
Modular paralleling options open up in this range for both diesel and gas.
- Diesel: SD200, SD230, SD250 (8.7L), SD275, SD300, MD300 (10.3L)
- Gaseous: SG200, MG200, SG230, SG250, MG250, SG275, SG300, MG300 (14.2L)
- Typical sites: warehouses, cold storage, municipal buildings, larger clinics
350kW to 500kW Industrial Generators
This is the highest-volume industrial range, and the SD500 is one of the most common Generac units on the used market.
- Diesel: SD400, MD400 (12.5L), SD500, MD500 (15.2L), SD500-T4, MD500-T4 (18.1L)
- Gaseous: SG350, MG350, SG400, MG400, SG450, MG450 (21.9L), SG500, MG500 (25.8L)
- Typical sites: hospitals, water and wastewater plants, data center rooms, large manufacturing
600kW to 1MW Large Standby Generators
Generac builds a 1MW gas generator as a single unit, which is uncommon across the industry.
- Diesel: SD600, MD600, SD750, MD750 (18.1L), SDMD900, SDMD1000 (30.6L)
- Gaseous: SG625, MG625, SG750, MG750 (33.9L), SG1000 (49.0L)
- Typical sites: hospitals, campuses, industrial plants, data center halls
1.25MW to 1.5MW Generators
Generac’s newest diesel platform runs a 46.0L Perkins V-12 and began shipping in the second quarter of 2026.
- Diesel: SD1250, MD1250, SD1500
- Typical sites: data centers, healthcare, water utilities, heavy industrial
2.25MW to 3.25MW Data Center Generators
Generac’s largest diesels run Baudouin engines and are built for data center campuses.
- Diesel: SDMD2250, SDMD2500 (65.6L), SDMD2750, SDMD3000, SDMD3250 (87.5L)
- Features: Marathon DataMAX alternators and optional redundant starting systems
- Typical sites: data center campuses, large hospital systems
Older Generac Models on the Used Market
Generac has changed engine platforms several times, so a used unit may not match today’s spec sheet. An older SG100 ran a 9.0L engine where the current model runs 8.8L, and older SD035s used a 3.4L diesel instead of today’s 3.3L. You’ll also see discontinued models like the Gemini MD01000GEM, the IDLC1250, and the IDLC2000, along with SD350 and MD350 diesels that no longer appear in the current lineup.
Parts support for most older Generac engines is still strong. Confirm the engine model before comparing a used unit against a new quote. Generator Source keeps spec sheets for current and legacy Generac models in its Generac spec sheet library.
Two Ways to Buy a Generac Industrial Generator
You can order a new Generac from the factory through your territory’s distributor, or buy from an independent supplier that stocks new, surplus, and used units.
Factory order through a distributor. You spec the unit and wait for it to be built. Generac quotes 30 to 36 weeks for open generator sets, and enclosed or heavily configured units can take longer. You get one condition, new.
Generator Source. Generator Source isn’t a Generac distributor. It buys and owns its inventory outright and sells Generac units in every condition:
- New: zero-hour Generac units in stock and ready to ship, like this 30kW SD diesel in Brighton, plus factory-new units sourced for projects that need a specific configuration or Tier 4 Final
- New surplus: unused units from cancelled or over-ordered projects, below factory pricing and available now
- Used: inspected Generac units from 20kW to 2MW
One conversation covers all three side by side. The sales team can tell you whether a stocked unit fits before you commit to a 30-week wait, and if a factory order is the right answer, Generator Source can source that too.
Support continues after delivery. EGSA-certified technicians in Brighton, Jacksonville, Pensacola, and Austin handle preventive maintenance, load bank testing, and emergency service on Generac units of any age. Rental generators can bridge the gap while a permanent unit is on order. Many buyers can also write off the purchase under Section 179.
Generac Industrial Generator FAQ
How much does a Generac SD500 cost? A new Generac SD500 500kW diesel generator costs an estimated $150,000 to $225,000 for the unit alone in 2026, before installation. The MD500 paralleling version costs more. A used SD500 typically sells for 20% to 35% of the new price, depending on age, hours, and enclosure.
How much does a 1MW Generac generator cost? A new Generac SDMD1000 1MW diesel generator costs an estimated $275,000 to $375,000 for the unit alone. The SG1000 natural gas version costs more.
What’s the difference between Generac SD and MD generators? SD generators are single, standalone units. MD generators are built to parallel with other Generac units as part of a modular system, which adds redundancy and lets a facility add capacity later. MD units cost more because they include paralleling controls.
What’s the difference between Generac SG and SD generators? SG generators run on natural gas or propane. SD generators run on diesel. Gas units avoid on-site fuel storage and can run as long as the utility supplies gas, while diesel units cost less per kW and don’t depend on a gas line.
How long does it take to get a new Generac industrial generator? Generac quotes 30 to 36 weeks for open generator sets built to order, and enclosed or configured units can take longer. Stocked new, new surplus, and used units can ship in days.
Do I have to buy a Generac industrial generator from an authorized distributor? No. Independent suppliers like Generator Source sell new, new surplus, and used Generac generators. Warranty coverage depends on the specific unit and how it was sourced, so confirm coverage before you buy.
Is a used Generac industrial generator worth buying? A used Generac can save 65% to 80% compared to a new unit and ship immediately. The best candidates have low hours, documented maintenance, and a recent load bank test. Most older Tier 2 and Tier 3 units remain legal for emergency standby.
Ready to Price a Generac Generator?
- Browse Generac generators for sale →
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- Call 877-866-6895 to compare new, new surplus, and used Generac options.