Top 5 Factors Affecting Generator Output Rating

The threat of a power outage is growing increasingly common in Texas due to severe weather patterns that put a strain on the state’s grid.

As a commercial property owner, it’s crucial that you invest in an industrial generator. Having a backup power source can keep maintenance issues and profit losses at bay.

However, you’re going to need to learn a thing or two about the generator output rating first. Generator ratings determine how much energy a generator can produce at full capacity and under optimal conditions.

It’s not always easy to make heads or tails of how generator output ratings are established. Read on to learn about five factors that can impact a generator’s output rating, including factors that cause derating.

1. Engine Size and Generator Output Rating

When a generator is manufactured, it is assigned a generator output rating by the manufacturer. This rating determines the maximum amount of energy output a generator can have when it’s working in the best circumstances. Generally speaking, that means that the generator is located at sea level with moderate temperatures and pressure levels.

When you’re considering the manufacturer’s generator output rating, the size of the engine is going to make a big difference. The size of the generator engine paired with its maximum output may also be referred to as capacity.

The first step in selecting the right generator is ensuring that it has the capacity or output rating to power your entire commercial building. Keep in mind, however, that most of the time, you’re going to want to run that generator at about 80% power to conserve fuel and avoid maintenance issues. Only in an emergency will you want to crank your generator up to 100%.

2. Fuel Type and Efficiency

Engine size isn’t the only thing that determines a generator output rating. In fact, you may encounter generators with equal-sized engines that have different output ratings because efficiency also plays an important role. When you’re looking at industrial generators, you’ll notice that you have a few different fuel types to choose from, most commonly diesel and natural gas.

Diesel Generators

Diesel generators are the more efficient option because diesel has significantly higher peak energy density than natural gas. In other words, you get more energy output per gallon of diesel than per gallon of natural gas.

Though diesel costs more than natural gas per gallon, diesel generators tend to yield lower costs. Due to increased efficiency, you’ll actually get more energy per dollar spent. Plus, diesel generators have a longer lifespan with the proper maintenance.

Natural Gas Generators

Natural gas generators aren’t as efficient as diesel generators but that doesn’t make them a poor choice for industrial use. In populated areas like Houston, natural gas is readily available. You can also install a supply line to your property to ensure ease of access.

Natural gas also emits lower levels of pollutants. Natural gas generators also tend to generate less noise than diesel generators, making them less disruptive to use.

3. Cooling and Ventilation

As we mentioned earlier, the initial generator output rating that an industrial generator receives pertains to its maximum capacity under optimal conditions. What happens when those conditions are no longer optimal? The generator begins to work less efficiently, causing what is known as derating.

External temperature isn’t the only concern. Generators can overheat if they are not able to properly ventilate, which keeps the internal mechanisms cool. Ventilation is controlled by the generator:

• Radiator
• Air intake system
• Exhaust system

If a generator overheats, it can cause serious damage to many of the mechanisms, which can be expensive to repair or replace. You can prevent overheating by staying on top of basic maintenance, like refilling the coolant, filling the generator with proper amounts of fuel, and cleaning components like air filters and engine parts.

4. Altitude and Climate

Unfortunately, some conditions that cause derating may be out of your control. Altitude and climate can have a significant impact on your generator’s output rating, reducing its ability to work efficiently.

Altitude

As mentioned earlier, a manufacturer’s generator output rating pertains to generators operating at sea level. For every 1,000 feet above sea level your property is located, you should reduce a diesel generator’s output by 2-3%. If your generator runs on natural gas, that derating increases to 5%.

In Houston, altitude doesn’t present much of an issue. However, parts of West and North Texas are well above sea level and generators will experience derating as a result.

Climate

High temperatures and humidity can also reduce your generator’s capacity to work. In Houston’s subtropical climate, this presents a bigger issue than altitude.

High temperatures tend to yield lower air density. The moisture present in the air during high levels of humidity can also displace oxygen. Low oxygen levels have a negative impact on combustion, meaning that your generator may try and fail to operate at its full capacity.

5. Proper Maintenance

We’ve already touched on some of the ways that maintenance can prevent derating. For example, keeping your generator’s engine clean can reduce the chances of overheating.

It’s important to have your generator inspected and serviced after about 100 to 200 hours of use or once a year, whichever comes sooner. Many of the issues that can reduce efficiency are hard to spot, and a professional inspection can ensure that your generator will work when you need it to.

Regular maintenance can also reduce overall costs. When an industrial generator requires extensive part replacements or repairs, you may find that it costs less to replace the entire thing.

Looking for Used Generators in Houston?

If you’re in the market for an industrial generator, the first thing to consider is the generator output rating of the model you’re considering. Use our guide to account for any conditions, like climate, that can cause derating. The right generator will keep your commercial property powered in an outage, and you deserve a generator you can count on.

Are you looking for used generators in Houston? Do you have an industrial generator that you want to sell? Contact Swift Equipment Solutions and let us know how we can be of service.