Diesel Generators

Reliable Diesel Generators for Industrial, Commercial and Backup Power

A diesel generator is one of the most dependable ways to protect homes, businesses, sites and critical operations from power loss. From small backup units to high-capacity industrial systems, diesel remains a trusted choice because it offers strong performance, long service life and efficient running under load.

At Global Generators, we supply new diesel generators from the UK for customers across the UK, Europe and worldwide. Our range covers single phase and 3 phase models, silent canopied sets, containerised units and open generator sets for plant rooms, compounds and specialist installations. Every model is built for 50Hz power, making our range suitable for UK, European and many international applications.

We have diesel generators for sale from leading brands including Cummins, Grupel and Pramac, with engine options from Cummins, Perkins and Yanmar. As an authorised Cummins CPG dealer and an authorised Grupel and Pramac dealer, we offer highly competitive pricing across all three ranges, supported by a large physical stock ready for fast dispatch.

Diesel Generators from 10 kVA to 3000 kVA

Our diesel motor generator range covers a broad spread of power outputs, so it’s easy to find the right set for your site. Whether you need a compact generator for essential backup at a home or small business, or a high-capacity unit for industrial or commercial operations, there’s a generator to match.

Models start from 10 kVA (8 kW), suitable for home emergency backup and smaller commercial loads, and go all the way up to 3000 kVA (2400 kW) for large facilities, data centres, heavy industry and mission-critical infrastructure. Single phase models are available from 10.8 kVA to 30 kVA, and 3 phase models across the full range. Silent canopied sets are available up to 2750 kVA, and open sets from 640 kVA to 3000 kVA.

Key features across the range include:

• Electric start as standard
• Digital control panels with automatic start and stop on most sets, so they can be paired with an ATS panel for automatic changeover during power cuts
• AVR (Automatic Voltage Regulation) alternators for stable, reliable output
• Built-in base fuel tanks on every silent set, from 24 to 1000 litres, with separate fuel tanks available for longer runtimes
• Silent canopied designs for lower noise and weather protection

With such a broad selection, it’s straightforward to match the right generator to your required output and operating environment.

Diesel Power for a Wide Range of Applications

Diesel power is used wherever a reliable power supply is essential. That might be a standby diesel generator for a business premises, a diesel generator off grid for a remote site, or a larger industrial package for continuous power in a demanding environment.

Our customers use diesel gen sets for factories, farms, construction sites, data centres, telecoms, healthcare, retail, hospitality, residential backup and export projects. A well-specified generator/diesel generator set can support anything from lighting and security systems to heavy machinery, cooling equipment, pumps, compressors and full-site electrical loads.

Diesel vs Petrol and LPG Generators

Compared with a petrol generator or a gas generator, a diesel fuel generator is usually better suited to larger loads, longer run times and commercial use. Diesel engines are designed for strength and efficiency, which makes them ideal for standby power, emergency backup and prime power applications. Thanks to the efficiency of diesel, diesel generator sets offer a more economical and reliable solution.

Here’s how the three fuels compare at a glance:

Fuel Efficiency and Lower Running Costs

Diesel holds more energy per litre than petrol or LPG, and diesel engines turn more of that energy into useful power. As a result, a diesel generator uses less fuel to deliver the same output, which significantly lowers running costs over long runtimes or continuous use - an important factor for anyone relying on backup or off-grid power.

Greater Longevity and Durability

Diesel engines are built more ruggedly than petrol engines to withstand the high compression ratios needed for compression ignition. This heavy-duty construction means they are engineered for continuous operation and can handle demanding environments where reliability is non-negotiable. As a result, diesel generators typically have a much longer operational lifespan than petrol models, which are usually intended for lighter, more intermittent use.

High Torque for Demanding Loads

Diesel engines also produce higher torque, making them particularly effective at starting and running equipment with high initial power demands, such as motors, pumps, compressors and air conditioning. A correctly sized diesel generator handles large load steps well, recovering quickly when heavy loads are switched on and helping to keep voltage and frequency stable, protecting sensitive electrical equipment from fluctuations. This makes diesel motor generators a trusted choice wherever robust, dependable power is essential.

Safer Fuel to Store and Handle

When it comes to fuel safety, diesel is a far more secure choice than petrol or LPG. It is much less volatile than petrol, with a flash point above 55°C compared with around -40°C for petrol, so it is far less likely to ignite from an accidental spark or minor heat source. Petrol vapours ignite easily, and LPG, while widely used, poses a risk if leaked, as it is heavier than air and can gather in low-lying or enclosed spaces.

This makes diesel a safer fuel to store on site and to use in sensitive environments. Whether you’re storing fuel for a backup generator at a warehouse, a construction compound or a data centre, diesel reduces the risk of accidental fires and dangerous vapour build-up during day-to-day operation.

If you need to store more fuel than your generator’s integrated base tank holds, we offer additional standalone fuel tanks from 450 to 10400 litres for the safe storage of diesel.

Widely Available and Suited to Longer Storage

Diesel is stocked worldwide, thanks to its extensive use in transport, agriculture and construction. You’ll find it at almost any commercial refuelling point, making it much easier to source in an emergency or on a remote site.

Diesel also keeps for longer than petrol. Petrol can deteriorate within a few months, while diesel stored in a clean, sealed tank typically stays usable for 6-12 months, and longer with fuel testing and treatment. This makes it particularly valuable for standby generators, where fuel may sit unused for months but must still deliver reliable performance the moment it’s needed.

Modern UK diesel contains up to 7% biodiesel (FAME), which attracts water and can encourage microbial growth, often called “diesel bug”. For standby sets, keep tanks topped up to limit condensation, drain off any water regularly and have stored fuel tested periodically.

Reliable in Hot, Cold and High-Altitude Conditions

Diesel generators are generally less affected by extreme conditions than petrol engines. With winter-grade diesel and an engine coolant heater, they remain highly reliable in cold weather. Turbocharged diesel engines also lose less power at altitude than carburetted petrol engines. Most generators do still need derating above a certain altitude, typically around 1000m, or in very hot climates, so check the data sheet or ask our team when specifying a set for a site abroad. For exposed or remote locations, a silent canopied set adds weather protection as well as quieter running.

In short, for applications where reliability, efficiency and resilience are key - whether that’s commercial backup, remote sites or critical infrastructure - diesel generators consistently provide a dependable power solution.

Which Fuel Can You Use in a Diesel Generator?

Every diesel generator we supply runs on standard white diesel (EN 590) and on HVO (EN 15940). Whether you can legally use red diesel depends on what the generator is used for.

Red Diesel and Generators

Since 1 April 2022, most businesses in the UK can no longer legally run generators on red diesel (rebated gas oil). Unless your use qualifies for an exemption, a diesel generator must run on white diesel, also known as road diesel or DERV, which carries the full rate of fuel duty. This includes generators on construction sites and at events, and standby generators for commercial premises such as offices, factories, shops, warehouses and data centres.

Red diesel can still be used in generators that are used for:

• Agriculture, horticulture, fish farming, forestry and arboriculture
• Generating electricity or heat primarily (75% or more) for non-commercial premises, such as homes, places of worship, NHS hospitals, state schools, town halls, public libraries and registered charities’ premises used for their charitable purpose
• Operating or maintaining equipment at travelling fairs and circuses
• Golf courses, driving ranges and community amateur sports club (CASC) land

Using red diesel when you’re not entitled to is treated as fuel duty evasion. HMRC can seize both the generator and the fuel, recover unpaid duty going back up to 4 years and impose civil penalties. Serious cases can lead to an unlimited fine or up to 7 years’ imprisonment. Red and white diesel must not be mixed in the same tank.

If you’re unsure whether your use qualifies, check HMRC’s Excise Notice 75 before buying fuel. Outside the UK, rules on marked and rebated fuels vary by country, so export customers should check local regulations.

Running Diesel Generators on HVO

HVO (hydrotreated vegetable oil) is a renewable diesel made from waste fats and vegetable oils to the EN 15940 standard. Depending on the feedstock, it can cut lifecycle CO₂ emissions by up to 90% compared with fossil diesel.

HVO is approved for use in every diesel generator we supply. Cummins approves HVO for its generator sets, Perkins confirms its engines can run on up to 100% HVO or blends with diesel with no engine conversion, and Yanmar describes EN 15940 HVO as a drop-in replacement for its industrial diesel engines, with no special modifications or changes to maintenance intervals. That covers our full Cummins, Grupel and Pramac range.

HVO can be used on its own or blended with standard white diesel. Because it contains no FAME, it absorbs less water and is less prone to diesel bug than standard diesel, making it a good fit for standby generators where fuel sits for long periods, and it performs well in cold weather. HVO costs more per litre than standard diesel and holds slightly less energy per litre, so fuel consumption by volume may be marginally higher.

For fuel duty, HVO follows the same rules as diesel, so unless your use qualifies for one of the red diesel exemptions above, it must be full duty-paid.

Silent, Open, Canopied and Containerised Options

Choosing the right configuration is just as important as choosing the right size. Silent diesel generators are fitted inside acoustic canopies to reduce noise, protect the equipment and make outdoor installation easier. These are often the best choice for commercial premises, residential backup, farms, workshops and sites where noise levels matter. The noise level of every model is listed on its product page, and our silent sets typically measure between 64 and 75 dB(A) at 7m.

Open diesel electric generators are typically used indoors, inside plant rooms or within purpose-built enclosures. They are a good option where the generator already has protection from weather and where access for installation, servicing and airflow can be planned around the site layout.

For larger power requirements, containerised diesel gensets provide a robust, secure and practical power solution. They are commonly used for industrial sites, utilities, export projects and high-power standby generators where durability and ease of transport are important.

For temporary or changing sites, our mobile, trailer-mounted generators are available up to 275 kVA, ready to tow into position wherever power is needed.

Single Phase and 3 Phase Power

We supply both single phase and 3 phase diesel generators from the UK. Single phase models are often suitable for homes, small workshops, offices, farms and smaller commercial buildings. They can support lighting, sockets, heating controls, security systems and other everyday electrical loads.

3 phase diesel generators are designed for larger commercial and industrial environments. They are commonly used for machinery, production equipment, motors, pumps, HVAC systems and full-site backup. If your site has a 3 phase supply, you will usually need a 3 phase generator diesel system to match the existing electrical infrastructure.

Our team can help you compare kVA, kW, voltage, phase type and starting loads so the generator set is properly matched to your application. This is especially important where motors, compressors or other high-starting-current equipment are involved.

Standby, Prime and Continuous Power

Different sites need different operating modes. A standby diesel generator is designed to provide emergency power when grid power fails. It normally remains idle until there is an outage, then starts automatically or manually to restore supply.

Prime power models are used where the generator is the main source of electricity for extended periods. This is common for off-grid locations, remote industrial sites, temporary facilities and export projects where mains electricity is unavailable or unreliable.

Some applications also require continuous power, where the generator runs for long operating periods under a steady load. In these situations, correct sizing, ventilation, fuel planning, control systems and maintenance access all become especially important.

Typical Runtimes and Fuel Tank Sizes

When choosing a diesel generator, it’s important to consider both runtime and fuel tank capacity, as these directly affect how reliably your backup or primary power system performs.

Every generator in our standard silent canopied range, up to 550 kVA, has a built-in base fuel tank, from 24 litres on the smallest sets up to 995 litres on the largest. Runtime depends on both tank size and fuel consumption, and base tanks are sized up in line with the higher fuel consumption of larger engines. At 100% prime-rated load, typical runtimes are:

• Up to 66 kVA: 24-200 litre tanks, around 6-38 hours
• 67-220 kVA: 200-464 litre tanks, around 8-17 hours
• 221-550 kVA: 400-995 litre tanks, around 7-17 hours

For example, the Pramac GBW22P holds 51 litres and runs for around 9 hours at full prime load, the Grupel PL110D5 holds 200 litres for around 9 hours, and the Cummins C550D5QB holds 995 litres for around 11 hours, each enough for a full working shift or an overnight power cut. Runtimes are longer at lower loads, and the fuel consumption and autonomy of every model are listed on its product page.

Our range of open-type Cummins diesel generators (640-3000 kVA) don’t feature integrated fuel tanks as standard and require connecting to an external fuel supply. If you need a fuel storage solution for an open-type unit, or require a longer runtime from a canopied set, we can also supply additional free-standing fuel tanks ranging from 450 to 10400 litres.

Long runtimes make diesel motor generators an excellent fit wherever refuelling during operation would be awkward or impractical. Always make sure the fuel supply is sized for your intended use - whether that’s standby backup for the odd power cut or prime power for extended periods.

Automatic Backup with ATS Panels

For many backup applications, an automatic transfer switch is a key part of the system. When grid power fails, the ATS detects the outage, starts the generator and transfers the electrical load. When mains power returns, it transfers the load back and shuts the generator down safely.

This creates a smooth emergency backup system for businesses that cannot afford long interruptions. It is particularly useful for sites with refrigeration, IT equipment, telecoms, security systems, production lines, healthcare facilities or essential building services.

We can supply control panels and transfer equipment to help create a complete diesel power generator package. The right control setup makes operation simpler, safer and more reliable.

We offer Cummins GTEC ATS panels from 40A (9 kVA single phase / 27 kVA 3 phase) up to 2000A (1385 kVA 3 phase). Although they’re Cummins products, they’re compatible with all brands of generators that feature any digital control system, such as a Cummins PowerStart or PowerCommand, Deep Sea or ComAp control panel.

New Diesel Generators from Trusted Brands

Global Generators supply all brand new equipment, nothing used/2^nd hand or for hire. This gives customers the benefit of unused machinery, clear specifications and long-term value.

Our Cummins range is especially strong. As an authorised Cummins CPG dealer, we offer the UK’s best pricing on Cummins diesel generators, backed by expert product knowledge and physical stock. We also supply Grupel and Pramac generator sets powered by Perkins and Yanmar diesel engines, giving customers additional choice across a wide range of power ratings.

Some buyers also compare our range with other well-known names such as CAT, FG Wilson and MTU. Our team can help you compare output, engine manufacturer, canopy design, alternator specification, controller type, price and availability so you can choose the most suitable diesel genset for your site.

Understanding Diesel Generator Prices

Diesel generator price depends on several factors, including power rating, brand, engine type, alternator, canopy design, control system, fuel tank, phase type and optional extras. A compact single phase model for home backup will usually cost far less than a containerised industrial generator built for high-power standby or prime use.

The cheapest option is not always the best long-term value. A properly specified diesel generator for sale should be matched to your load, site conditions, installation plan and future requirements. Undersizing can cause performance issues, while oversizing can reduce efficiency and increase unnecessary cost.

If you are comparing a diesel genset price, check what is included. Important details include whether the unit is silent or open, whether delivery is included, what control panel is fitted, whether an automatic transfer switch is required, and whether the generator is available from stock.

Fast UK Delivery and Global Export

We are a leading stockist of generators and diesel equipment, holding a wide range of models in our physical inventory. This helps us offer fast delivery across the UK and efficient export worldwide.

Customers searching for diesel generator UK suppliers often need more than a brochure and a long factory lead time. They need real availability, clear pricing and practical advice from people who understand generator supply.

We regularly support customers looking for generators/diesel generators Europe-wide, as well as buyers in the Middle East, Africa and other international markets. Supplying from the UK gives customers access to high-quality industrial equipment, export support and responsive communication throughout the buying process.

Choosing the Right Diesel Motor Generator

The right DG (diesel generator) depends on how it will be used. Start by listing the equipment you need to power, then consider whether the generator will be used for standby, prime or off-grid operation. You should also check whether your site needs single phase or 3 phase output. Our power conversion calculators can help you convert between kVA and kW or work out the current in amps.

Fuel capacity, noise levels, space, ventilation, access, delivery route and installation location all matter. Diesel fuelled generator packages for remote sites may need a larger fuel tank and strong weather protection, while a commercial standby set may need an ATS panel and acoustic canopy.

While there are many different names people use to describe a generator/diesel motor generator, they all boil down to the same basic requirement: a diesel engine driving an alternator to produce electricity. The most important thing is choosing equipment that suits the load, environment and duty cycle.

Why Buy from Global Generators?

Global Generators combines stock, pricing and experience. Our team has over 50 years of combined experience in the generator industry, helping customers choose the right equipment for reliable standby power, prime power and emergency power.

We offer generators for sale from the UK for customers who need fast access to quality equipment. Our range includes diesel generators for sale UK-wide and worldwide for export, and diesel genset for sale options across a wide range of sizes.

We understand that every site is different. Some customers need a simple backup unit for a small business. Others need a high-capacity industrial system with control panels, ATS integration and export documentation. Our role is to make the buying process clear, practical and efficient.

• Extensive Range: We stock a wide selection of diesel motor generators, from compact 10 kVA sets for home or small business backup to 3000 kVA sets for industrial and commercial use. Whether you need a mobile, trailer-mounted generator or a permanent installation, we cover every requirement.
• Expert Advice: Our experienced advisors are on hand to help you assess your site’s needs, calculate your power requirements and select the right unit. We focus on supplying the correct kVA, configuration and features to match your application.
• Quality Brands: We supply diesel generators from Cummins, Grupel and Pramac, featuring Cummins, Perkins and Yanmar engines, Stamford, Leroy Somer, Mecc Alte and Linz alternators, and Cummins, Deep Sea and ComAp digital control systems, so you benefit from proven reliability and industry-standard technology.
• Rapid Availability and Delivery: We hold essential power sizes in stock at our facility in Doncaster, UK, available for same-day collection, fast nationwide delivery with dispatch as early as next day, or worldwide export for international customers.
• Customer Commitment: We pride ourselves on clear communication, responsive service and ongoing support. From your first enquiry to after-sales warranty liaison and technical advice, our team is committed to your satisfaction.
• Quality Assurance: Every generator we supply is brand new, factory tested by the manufacturer, inspected by our team and backed by the manufacturer’s warranty. Additional testing is available on request.

Frequently Asked Diesel Generator Questions

Speak to Our Diesel Generator Experts

Whether you need standby power for a business, emergency power for a critical site, or a larger diesel power solution for industrial use, Global Generators can help. Contact our experts today for more information about our range of diesel generators or to reserve your generator via phone, WhatsApp, email, or enquiry form.

Our experienced team will help you select the right diesel generator for your needs, with expert advice and fast responses from your first enquiry through to technical and after-sales support. With extensive stock and fast delivery, we’re well placed to meet urgent requirements, wherever you are. Whether you’re buying a Cummins, Grupel or Pramac generator, we can answer your questions, recommend suitable models and help you compare specifications and pricing.

Have a question or need advice? Don’t hesitate to get in touch - our friendly team is here to help you every step of the way.