Standby power generators

Diesel backup generators offer efficiency, reliability

A power outage isn’t just a power outage for many industries. Think hospitals, 911 call centers blood banks, data centers. When a loss of power means the difference between life and death, being in the dark simply can’t happen.

If failure just isn’t an option, then it might be time to consider a backup generator, or a generator with a standby rating. These generators supply power during emergency situations for a limited duration. Since backup generators aren’t prime power sources, these types of generators don’t need to follow Tier 4 generator guidelines.

While standby generators are designed only for emergency outage situations—hence the term “backup”—they are outfitted to supply real power when you need it most. Typically built for optimization of about 50-80 percent total load rating for about 200 hours per year, backup generators will be able to supply the energy you need, when you need it.

There are two choices for fuel when researching backup generator options for your business: natural gas and diesel generators. Which fuel source is optimal for your application will depend on a number of factors. In the natural gas industry, for instance, that fuel source is a potentially beneficial solution because it’s already on-site and doesn’t incur transportation costs. Natural gas is also cheaper per unit, but it’s important to note that diesel is more efficient, and therefore often ends up costing less in the long run. Also notable is that while diesel generators are oftentimes more expensive than natural gas generators, the low maintenance cost makes up for the initial investment.

Diesel is the more efficient, environmentally friendly choice for high kW endeavors, and where there are code specifications for on-site fuel storage such as in hospitals.

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Despite being reliable backups, standby generators do require some regularly scheduled maintenance and testing in order to ensure that it will be ready to kick on when needed.

Before using a diesel backup generator, you should also become acquainted with wet stacking, why it’s problematic and how to fix it when it occurs.

You can read more in depth about wet stacking here, but here’s a recap of what you need to know. Wet stacking refers to the buildup of unburned fuel or carbon in and around the exhaust side of the engine. This occurs when a generator is being light loaded, or run below the recommended 50-80 percent total load rating. When the engine is running below capacity, the engine doesn’t reach the optimal running temperature needed to completely burn fuel, allowing for unburned fuel to escape the combustion chamber.

Additionally, light loading can cause piston rings not to reach a temperature that allows them to expand fully, allowing fuel and gasses to escape into the oil pan. Short term use won’t cause permanent damage, but it is important to try and use diesel backup generators at their sweet spot—50-80 percent capacity—in order to avoid irreparable damage to the engine.

Light loading can lead to real consequences for you and your business — unscheduled downtime, higher maintenance costs and decreased fuel efficiency. It can even shorten the overall lifespan of your generator.

Luckily, wet stacking can be avoided by running your generator at recommended capacity, and also through regular maintenance conducted by an experienced power professional.

Beyond regularly scheduled maintenance, generator owners should also focus on proper use of their equipment to ensure the longevity of their investment. These measures include not light loading your equipment and periodic load bank testing.

Load bank testing is one technique used to prevent wet stacking and ensure optimal performance of your generator when you need it. Benefits of this procedure include verifying that your generator is working, testing that your gen set is capable of operating at its specified kW output and burning off excess residue caused by light loading.

So, what exactly is load bank testing? Load banking refers to the process of subjecting a gen set to an artificial load at its maximum capacity for a specified period of time. The increased artificial load dually serves to verify your generator is able to work at peak outage, as well as reaching the extreme temperatures to reverse wet stacking buildup in the exhaust.

To read more about diesel backup generators — and to learn about running a generator efficiently in general — be sure to download and check out our guide below.