How to Calculate the Heat Rate of a Diesel Generator?

Generators are reliable alternate power sources that come in handy in emergencies resulting in power outages.

While several industries rely on different kinds of generators, diesel generators are becoming quite popular across industries for their several benefits.

As a diesel generator requires lesser components to produce the required energy, they are low on maintenance. Their fuel consumption rate is lower than other generators, making them fuel-efficient, and they are highly durable and can withstand pressure conditions without breaking down.

Not just that, diesel generators enjoy a long lifespan, provide a continuous power supply, and can handle larger power loads than their counterparts.

Furthermore, diesel is a much safer fuel to store as compared to gasoline that is highly combustible and explosive, making diesel generators safer to store on-premises.

While all these benefits have made diesel generators a preferred choice with most industries, it is also important to know their heat rate (efficiency) and how you can calculate it.

What is Meant by the Heat Rate of a Diesel Generator?

Heat rate calculation is most commonly carried out in British thermal units (Btu) per kilowatt-hour (kWh). In simple terms, it is the thermal efficiency of a generator, which is calculated by dividing the energy produced by burning the fuel to generate electricity, by the total output of electric energy produced in the process.

Simply put, the lower the value of heat rate, the better will be the efficiency.

Factors Determining the Heat Rate of a Diesel Generator

There are certain aspects based on which the value of heat rate of a diesel generator can be speculated. Let’s look at them individually:

Fuel Cost

A power generator’s performance very rarely remains the same every day. Its output can be different on different days and thus it is difficult to calculate the exact efficiency. This variation in capacity generates different heat rates, which will affect the fuel cost.

The total fuel cost can be calculated by multiplying the heat rate with the total cost of the fuel per Btu.

Heat Rate Degeneration

The heat rate of a diesel generator goes down as its capacity or the efficiency to generate electricity increases over time. It is estimated that the heat rate of simple cycle units degrades at a rate of 0.2 percent every year, while the heat rate of a combined cycle unit goes down by 0.05 percent per year.

How to increase the efficiency of a diesel generator?

A generator’s efficiency is something that can be bettered over a period of time and it is well within control. Its efficiency depends on the quality of fuel used, the quality of the equipment, and how you maintain it.

That said, there are definite ways of increasing its efficiency as well. All generators are designed for optimized performance and give energy output at the higher end of the spectrum.

But, one of the most common issues with diesel generators performing below their designed load capacity is due to Wet Stacking. It occurs due to the exhaustion of unburnt fuel when the generator is operated at low temperatures.

This builds up a choking system in the generator, lowering its performance. To avoid this, it is better to operate your generator within its optimal range.

Operating your diesel generator at light load for long periods will have an ill effect on its health. It might result in frequent downtime, require more maintenance, and an overall shortened shelf-life.

Utilizing the machine in its optimal range is the best way to keep it running for a long period of time with maximum efficiency.

If you’ve been contemplating whether or not your generator is working at full capacity, and is working flawlessly in terms of efficiency, you can always seek the assistance of our expert technicians here at Swift Equipment!

On the other hand, if you have been wanting to purchase a New or Used Generator that ensures an optimal level of efficiency, do browse our dedicated section and pick the one that best suits your needs, preferences, and budget.

Frequently Asked Questions About Heat Rate and Efficiency of the Generator

What Are The Factors That Affect The Thermal Efficiency Of A Diesel Generator?

All generators, irrespective of the fuel used, require proper weather conditions to function efficiently. Factors like fluctuating air pressure, temperature, and humidity can impact its performance.

What Size Of Electrical Generator Should I Choose For Maximum Efficiency?

The efficiency of a generator will depend on your requirements and its specifics. The most important thing to consider is the power output you require from your generator. Whatever your need be, choose a generator with 15-20 percent more capacity so that you always have enough power supply.

How Efficient Are Diesel Generators As Compared To Others?

Diesel generators are supposed to be far more efficient compared to their counterparts. The simple reason is that they are low on maintenance, have a longer shelf-life, can withstand harsh weather conditions, and can handle large power loads without disrupting the supply.