Prime Power Generator Guide: Diesel vs. Gas

Heavy-duty applications require heavy-duty power. And, unfortunately, some of the most demanding industrial jobs are isolated from a central electrical grid. In other instances, the task at hand is so critical that there is no room for utility power outages, such as in a hospital or cold-storage facility.

If you manage such an industrial or critical facility, then you need a constant source of electrical power that only a continuous power generator can provide.

What are Continuous Power Generators?

Continuous power generators, also known as prime power generators, serve as the primary source of electrical power for a given application and typically have an output ranging between 25 kilowatts and 1 megawatt. They can run continuously (24/7) at variable and maximum loads to completely replace the utility provider, if necessary.

Prime-rated generators are not to be confused with emergency standby generators, which are meant for emergency power only. Typically, standby generators shouldn't be run for more than 200 hours per year and cannot permanently replace the utility provider. Continuous power generators, on the other hand, can run for an unlimited number of hours when properly maintained.

Prime power diesel and natural gas generators are available. We will discuss the pros and cons of each fuel type in more detail below.

When Your Project Demands Prime Power 

Continuous power is a necessity, not a luxury, for applications where the electrical grid is either unavailable or unreliable for mission-critical operations. 

Diesel vs. Natural Gas Prime Power Generators

The first major decision for your project is the fuel source. Both diesel and natural gas generators are excellent choices for continuous power, but each has a distinct profile of costs, maintenance, and compliance. Your final selection should reflect the unique needs of your site and application.  

Expert Guidance: If your operation is remote and a gas line is inaccessible (like a military base or deep-pit mine), diesel is typically the logical choice. If your project has easy access to cheap, piped natural gas (such as a local fracking operation), gas may offer a better long-term operational cost profile.

EPA Regulation and Installation 

For continuous power, a standardized, off-the-shelf solution is rare. Expect a thorough sizing and planning process, as most prime power generators must be customized and built-to-order to match the application's exact load requirements. 

Compliance is Non-Negotiable 

Regulatory compliance is critical when planning for a prime power generator.

• EPA Tier 4: If you choose a diesel unit, it must comply with these stringent regulations designed to reduce nitrogen oxides and particulate matter emissions. 
• Local Codes & Air Quality: Critically, local codes and regional air quality compliance boards (like SCAQMD in Southern California) often supersede national EPA requirements and can be far more exacting. 

To ensure success, your project requires a certified installer who specializes in prime power and industrial applications. This professional will ensure all local codes and standards are met before installation begins. 

Utilizing Load Management 

In some cases, a continuous power generator can work in tandem with the utility provider in a process known as load management: 

• Peak Shaving: During peak demand, your generator can provide supplemental power to cover the difference after the utility reaches a pre-set threshold. 
• Revenue Generation: Utility providers may even pay the generator owner for supplying this supplemental power to stabilize the entire grid.