Sell My Generator — The Complete UK Guide

Diesel generators are bought and sold constantly across the UK — from small 20kVA standby sets leaving office refurbishments to large 1000kVA+ prime power units being decommissioned from data centres, hospitals, and industrial sites. Whatever size or brand you have, there's a buyer for it.

Types of Generator We Buy

Standby generators (emergency backup) — the most common type in the UK commercial market; provide power automatically when the main supply fails. Typically lower hours than prime power units because they only run during outages and tests.

Prime power generators — designed for continuous operation as the primary power source; used on construction sites, events, remote locations, and in areas without reliable grid supply. Accumulate hours faster than standby units.

Containerised generators — diesel generator set enclosed in a weatherproof, sound-attenuated acoustic canopy or full ISO container enclosure. The most common format for commercial standby sets.

Open set / skid-mounted generators — generator and engine on a steel base frame without an enclosure; typically used indoors or in purpose-built generator rooms.

Towable / portable generators — mounted on a road-legal trailer for easy site-to-site movement; widely used in construction, events, and utilities.

Major Generator Manufacturers

Perkins (UK — Caterpillar) — the most widely specified engine brand in the UK generator market. Perkins-engined generators from all major generator set manufacturers (FG Wilson, Broadcrown, Newage, Harrington) are the most common type in the UK. Key engine models: 403A, 404A, 1004G, 1006G, 2206A, 2506C — matched to generator outputs from 10kVA to 500kVA.

FG Wilson (Northern Ireland — Caterpillar) — the most recognised complete generator set brand in the UK. FG Wilson generators (Perkins and CAT-engined) are the default commercial standby choice in the UK market and consistently achieve the strongest resale values of any generator brand. Key models: P8.5E, P22E, P44E, P60E, P88E, P150E, P200E, P275E, P500E, P800E, P1000E, P1500E — kVA figures approximately match model numbers.

Cummins (USA) — major engine manufacturer with a very strong UK generator presence. Cummins-powered generators are found across commercial, industrial, and data centre applications. Key engine models: QSB3.9, QSB5.9, QSB6.7, QSL9, QSX15, QSK19, QSK38, QSK60 — covering outputs from 60kVA to 2500kVA+. Cummins sets from manufacturers including Broadcrown, Harrington, and Telford Electrical Services are widely traded.

Caterpillar / CAT (USA) — premium brand; CAT-engined generator sets are specified for the most demanding applications — data centres, hospitals, military, and large industrial sites. CAT sets consistently achieve the highest prices at resale. Key models: C3.4, C4.4, C7.1, C9, C13, C18, C27, C32 engines powering sets from 60kVA to 1000kVA+.

Volvo Penta (Sweden) — growing UK generator presence. Volvo-engined generator sets are well regarded for fuel efficiency and reliability. Key engine models: D5, D7, D9, D11, D13, D16 — covering 70kVA to 500kVA applications.

MTU (Germany — Rolls-Royce Power Systems) — premium brand for large high-output sets, data centres, and critical applications. Key models: Series 1600, Series 2000, Series 4000 — typically 400kVA to 3000kVA+. MTU sets hold exceptional value at the large end of the market.

Scania (Sweden) — Scania-engined generators are commonly found in the 200–600kVA range; good parts availability and well-understood by UK engineers.

SDMO / Kohler (France) — French manufacturer with strong UK presence. Key models: R88, R110, R165, R200, R275, R500, T700K, T1000 — widely used in commercial standby applications.

Doosan (Korea) — growing UK presence in the 200–750kVA range. Previously sold under the Daewoo brand; well-regarded for value.

What Affects Generator Value?

Engine hours — the primary value indicator after brand and kVA output. Standby generators with under 500 hours are considered very low use; prime power sets at 3,000–5,000 hours are mid-range. Low-hour sets from known provenance (hospitals, data centres, offices) command strong premiums.

kVA output — larger sets are generally worth more, though the relationship isn't linear. The most active trading ranges in the UK used market are 20–100kVA (commercial standby) and 200–1000kVA (industrial and critical power).

Acoustic canopy condition — canopy panels, louvres, and doors are scrutinised; damaged or missing panels reduce value. A well-maintained, clean canopy supports a strong price.

Service history and load test records — documentation of regular servicing (oil and filter changes, coolant checks, annual load testing) is expected by commercial buyers. Sets without service records are discounted.

Battery condition — the starting batteries on a standby generator are often neglected; dead or failed batteries are factored into offers.

Fuel tank condition — for sets with integral base fuel tanks, tank condition (rust, leaks) and the presence of diesel are noted.

Transfer switch / automatic mains failure (AMF) panel — the control and switching equipment that makes a set automatically start and transfer load is a key component; its condition and functionality matter.

Indicative Values (2026)

Values are indicative. FG Wilson and CAT-branded sets at the upper end of ranges; lesser-known brands at the lower end.

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