Diesel engines power the world’s most robust machines, including ships, power plants, and generators.
While many types of generators are available, diesel generators are popular due to their ability to provide backup power in environments where outages can result in lost productivity, reduced profitability, and health and safety concerns.
Diesel engines power generators by converting mechanical power into electricity, ensuring ongoing support for large-scale operations.
Discover everything you need to know about diesel engines and why they’re the most popular choice for diesel generators in our comprehensive guide.
Diesel generators combine two key components: the diesel engine and the alternator. As your generator’s “prime mover”, the diesel engine provides the primary mechanical power source and activates the engine’s pistons, which create a rotational motion and spin the alternator.
The alternator will then use this mechanical force to create electricity. So, if your home or business loses access to its grid supply, the generator will automatically provide reliable backup support.
Diesel generators are beneficial for a range of environments, including:
Diesel generators are available in a variety of sizes, making them ideal for low to high-power needs. However, a key factor you’ll need to consider when choosing a machine is the type of diesel engine you use.
Two types of diesel engines are available, including two-stroke and four-stroke engines. While both are similar, their primary difference is how many piston movements (strokes) are required to complete a power cycle.
As the name suggests, these engines complete a power cycle over two strokes. They’re compact engines with a simple design, which often translates to lower prices. The main benefit of a two-stroke engine is its ability to ensure faster power delivery, but the engines are also less efficient.
Smaller generators often use two-stroke engines, so they’re best suited to environments that require instant power for lower-scale operations.
Four-stroke engines complete the power cycle over four piston movements, using two crankshaft revolutions. The four-stroke cycle ensures a steadier supply of electricity and is also more efficient. But these engines are more complex with extra parts and valves.
Diesel generators with a higher capacity, like those used in industrial settings, often have four-stroke engines.
| Feature | Two-Stroke Diesel Engine | Four-Stroke Diesel Engine |
|---|---|---|
| Power Cycle | Completes in 2 strokes | Completes in 4 strokes |
| Power per Revolution | Produces power for every 1 revolution of the crankshaft | Produces power for every 2 crankshaft revolutions |
| Design | Compact and lightweight with less parts | More complex components, including additional valves |
| Fuel Efficiency | The diesel fuel is less efficient | A more fuel-efficient option |
| Emissions | Higher emissions | Cleaner combustion, lower emissions |
| Maintenance | Requires ongoing maintenance | Requires less maintenance |
| Cost | Usually cheaper upfront costs | More expensive due to the additional components |
| Typical Use | Small and portable diesel generators | Industrial and standby diesel generators |
Diesel engines are intricate machines that use a range of components. Each plays a role in turning diesel engine fuel into electrical power, ensuring your machinery, appliances, and equipment can run during a power cut.
The cylinder block is a crucial part of your internal combustion engine, as it houses the cylinder and offers structural support for other components. Cylinder blocks are highly durable to ensure they can handle high compression ratios.
Next, we have the cylinder head, which seals the combustion chamber. The head contains intake values, exhaust valves and the fuel injector.
When the combustion process begins, the piston will move up and down inside your engine cylinder, harnessing the force of compressed hot air and transmitting it to the rod. The piston essentially drives the crankshaft.
Crankshafts convert the piston’s linear motion into a rotational motion, activating the alternator and turning mechanical energy into electricity.
The connecting rod is vital to your diesel engine because it transfers the piston’s force into crankshaft rotation, ensuring your generator can produce viable energy.
Fuel injection involves spraying a mist of diesel fuel into the compressed air. The compressed air/fuel mixture ensures an effective combustion process and delivers reliable power.
The intake valve enables fresh air to enter the cylinder, while the exhaust valves release gases after combustion. These components result in fewer emissions and facilitate streamlined airflow.
The camshaft opens and closes the valves at the optimal time during each combustion cycle. It works simultaneously with the crankshaft and ensures the generator operates efficiently.
Each diesel engine also has a cooling system, which prevents overheating. The system can preserve your generator’s lifespan and avoid damage to its components. A lubrication system will also prevent wear and tear by circulating oil around the engine.
Diesel engines in generators are often more popular than petrol engines, as they use a compression ignition engine and don’t rely on spark plugs. The process is relatively simple, and most modern diesel generators have automatic transfer switches, ensuring a seamless transition to backup power.
Here’s how it works:
| Pros | Cons |
|---|---|
| Higher fuel efficiency when compared to petroleum products. | Diesel engines are often more expensive upfront. |
| Highly durable with a long lifespan. Proper maintenance can mean the generator lasts for decades. | They can cause more noise, but most generators come with silencing features. |
| Reliable power for heavy and continuous loads. | Heavier and less portable – most people use a professional installation service. |
| Lower fuel consumption over time. | Older engines have higher emissions. |
| Higher safety ratings – as diesel fuel is less flammable. | Requires regular servicing and safety checks. |
| Quick response and a strong torque. | The fuel can degrade over time, and proper storage is essential. |
At Solent Power, we go out of our way to supply our customers with reliable diesel generators that serve as lasting investments. As an authorised distributor, we offer a range of new and used generators that provide your home or business with reliable backup power.
Whether you’re looking for models with medium-speed diesel engines or high-speed diesel engines, we can help you choose a suitable machine. Please get in touch with our generator sales team today.
Diesel engines are prime movers in generators that convert diesel fuel’s chemical energy into mechanical energy. The mechanical energy powers the alternator, which creates electricity. If your generator’s diesel engine doesn’t work, it won’t be able to produce electricity.
A four-stroke engine is usually better because it offers more fuel efficiency and will last longer. These engines can also ensure continuous operation in environments with large-scale power needs. However, two-stroke engines can be beneficial for environments that need smaller generators.
Most diesel generator engines can run for between 12 and 24 hours, but this depends on the fuel consumption rate and whether you have a full tank. The most powerful diesel generators can exceed 72 hours of continuous power, but only when regularly maintained.
Diesel generators mostly run on white diesel fuel, known as ULSD (ultra-low sulphur diesel). However, some generators can also run on alternative fuels, like biodiesel.
Yes, they are. Diesel fuel has more energy per litre, and combustion happens during a higher compression rate. So, over time, it works out to be more cost-effective than petrol.
It depends on your manufacturer’s recommendations, but most require servicing after 250 to 500 hours of operation. If you don’t use the generator often, it’s a good idea to arrange a bi-annual service.
A professional team will inspect your diesel-powered generator and ensure it continues to operate efficiently.
Hospitals rely on electricity as it powers life-saving equipment and ensures patients receive ongoing care. Unlike a petrol spark ignition engine, diesel engines start quickly and are built for continuous operation.
They also ensure that industrial businesses remain operational and avoid expensive delays. Most importantly, diesel engines are safe because the fuel is less flammable than gasoline.
A diesel generator can last between 15 and 20 years, or up to 30,000 hours of operation. If you regularly maintain the generator and check fuel quality regularly, it will last for years.
UK diesel generators must meet EU Stage V emission standards, which means they often contain features like exhaust gas recirculation (EGR), selective catalytic reduction (SCR), and diesel particulate filters (DPF).
By implementing these measures, generator manufacturers in the UK can ensure that each model is compliant and efficient.
Solent Power Ltd (Company Number 12622565) is a company registered in England and Wales. Our registered office is located at Station yard, Bowes Hill, Rowlands Castle PO9 6BP. VAT No. 363504018