If you’re considering buying or renting a diesel generator, it is important to understand a bit about how one works. You’ll also need to know the benefits of owning one, the different grades of fuel available, and the process of transporting and storing diesel. Here is a brief primer on diesel fuel and how it applies to generators.

 

What is Diesel Fuel?

Without getting too scientific, diesel is a specific mixture of hydrocarbons created by the distillation of crude oil. It is much denser than gasoline and widely known to have a higher efficiency level than other types of fuel. For that reason alone, it is widely used for heavy equipment, including generators.

Drop of diesel fuel

 

Different Grades of Diesel for Generators

Not all diesel is alike and it is important to understand the different grades available. There are three options to choose from: Diesel Fuel Grade #1 (DF1); Diesel Fuel Grade #2 (DF2); and a blend of the two called Winterized Diesel.

DF1 has a lower viscosity, meaning it is less thick and flows more easily than DF2. In contrast, DF2 is less volatile than DF1, meaning it burns more slowly. The Winterized Diesel is a mix and acts as a medium-grade between the other two.

Why this is important has to do with operating an engine in the winter. In sub-freezing temperatures, diesel fuel becomes thick and starts to gel. In turn, the engine won’t operate when it gets to this state. The important distinction here in DF1 doesn’t reach this state until -60 degrees Fahrenheit, where DF2 starts gelling at only 10 degrees Fahrenheit. Winterized fuel is a blend and falls somewhere in between this range depending on the ratio used.

Confused? Don’t worry. Most fuelers will make this decision for you, but knowing the difference is important in understanding how your equipment works best.

Learn more about the different grades of diesel fuel.

 

How Does Diesel Power a Generator?

Diesel engines work through a process that utilizes internal combustion. This happens when the intake valve opens, bringing air into the cylinder. The piston then moves upward and compresses the air, at which point fuel is injected. The air, heated by the compression, ignites the fuel and forces the piston back down. This turns the crankshaft which spins the rotor between two polarized magnets within a magnetic field, creating an electrical current. As the piston returns to the top of the cylinder, the outlet valve opens and releases exhaust gases.

 

Diesel Fuel Consumption

In most cases, fuel consumption is dictated by the size of the generator (in kW) and the load at which it operates (half load, 3/4 load etc.). For example, a 100 kW diesel generator will use approximately 2.6 gallons of diesel per hour when run at 1/4 load, 4.1 gallons per hour at half load and 7.4 gallons per hour when run at full load. 

We’ve put together a diesel consumption chart to help you estimate the amount of diesel fuel your generator might consume under different loads. Keep in mind the chart is based on estimations, there are several variables that can either increase or reduce the rate of fuel consumption. 

 

Why Use Diesel Fuel?

While there are other alternative fuel options on the market, diesel remains the preferred choice for industrial generator use. The reason for this has to do with availability, pricing, and efficiency.

While natural gas is a popular fuel source in urban areas where municipal gas pipelines already flow, it can be difficult to transport it to places where the infrastructure does not exist. Even though transporting diesel has its pitfalls, it is more versatile in the type of environments it can reach.

In terms of cost, natural gas does cost less than diesel fuel. But the latter has much higher fuel efficiency. That means that purchasing the same amount of natural gas and diesel will yield a higher run time with the diesel. That reason alone is why many companies opt to use diesel generators for standby or emergency power supplies. Diesel engines also typically have longer shelf lives.

See more reasons why diesel generators are so efficient.

 

Transportation

For many companies, transportation of diesel remains one of the more difficult aspects of utilizing this type of fuel. Not only is there a risk of a spill, but it can also be difficult to transport to certain rural areas. Plus, after a certain number of gallons, hazmat guidelines have to be followed and the Department of Transportation has a whole host of regulations to consider. To put it simply, sometimes the hassle of transporting diesel to your job or worksite can be a real pain.

However, if your generator is in a fairly easy-to-access location, it might not be that much of a problem. There are many fueling companies that know the best ways to transport diesel and have the right equipment to get the job done. While diesel delivery costs a bit more, it is well worth it, in the long run, to ensure your generator has what it needs to run when you need it to.

 

Storage

Storing diesel is an underestimated part of running a diesel generator. Many companies see low diesel prices and become tempted to stock up while the cost is affordable. This isn’t always the best idea as the quality of fuel can start to degrade rapidly in as little as six months.

However, storing diesel fuel isn’t impossible. First, it is vital to keep the fuel stored away from water and condensation. In most cases, the best option is through the use of underground tanks. Learn more about the pros and cons of above ground vs underground storage tanks.

It is also important to drain and clean these tanks at a minimum of every ten years. You’ll also want to consider additives such as biocides to help prevent contamination from microbial growth.

 

Cleaning

As previously mentioned, one of the biggest problems associated with diesel fuel is the risk of contamination. Algae, bacteria, and fungi are all known to grow in improperly stored diesel. Furthermore, sediment in the tanks and oxidation can easily degrade the fuel. That’s why it is important to understand and invest in the diesel fuel cleaning process, also known as polishing.

During fuel polishing, a special technical process helps remove water and unwanted solids from diesel fuel through a specific process of filtering. Additives called biocides are introduced early in the process to help eliminate microbial activity. Because the method is somewhat technical, it is usually left to a trained technician with special equipment to complete. 

At Worldwide Power Products, we provide regular fuel polishing as part of our preventative maintenance services to ensure your fuel and generator work as and when needed.

 

Conclusion

Now that you’ve learned a bit more about what diesel fuel is and how it works to power your generator, you can now make an informed decision on not only the generator, but also on the other facets that come with owning a diesel generator such as storage, transportation, and maintenance. Of course, if you have any questions, it always pays to speak to a trained diesel generator specialist who can help you work through various aspects of purchasing a generator including whether diesel is the best option.

Ready to learn more about our line of diesel-powered generators or our fuel polishing services? We would be happy to help! Contact our team at World Power Products today to learn more.