Commercial properties are typically held to the highest of standards. Though this goes beyond simple liability, insurance, and safety compliance regulations. Tenants who rent space and businesses that operate inside a large commercial space have certain expectations about the reliability of resources. This is especially true for foodservice, animal care, sensitive goods, data centers, and medical supply companies, who often rely on consistent electrical service to maintain temperature-sensitive materials or secure valuable property.

When the power provided by the traditional electric grid goes down, many commercial properties will employ a large emergency generator to ensure consistent power for tenants, customers, and other sensitive areas.

If you are a commercial property manager or owner, you might wonder what are some of the best commercial power generators to protect your business?

The truth is, this is a somewhat flooded field with a lot of different quality options to consider. To help you filter through them to find the best commercial generator for your business, it helps to ask some key questions and account for some specific factors.

How Does a Commercial Standby Generator Work?

Also known as a “Stand By Generator” commercial generators are set up to monitor the system and will automatically start running when the power goes out. Though some of these systems do require a person to initiate them with a switch or by activating a lever.

Still, most of the best, modern standby commercial generators have an automatic transfer switch that interrupts the utility line in the event of an outage. The restoration of power is nearly simultaneous, which is a major factor for a property with temperature-sensitive inventory or equipment. Then when power supplied by the grid is reliably restored, the transfer switch immediately turns off the generator and returns itself back to standby mode.

It’s also worth noting that the best commercial standby generators have a more robust build quality and safety features than you find in even large equipment or a high-value residential generator. Most of them use thicker gauge steel rife with reinforcing structural components. The engine size in a high-quality commercial standby generator also tends to be larger and is often liquid-cooled for superior performance and less risk of a breakdown due to overheating. You will also find that the internal electronics also tend to be more robust with surge protectors that are specifically designed to handle the higher wattages and heat associated with longer run times as well as high-demand.

What Is A Prime Power Generator?

When it comes to commercial power applications when the traditional power grid is unavailable, a primary generator can be used to provide a significant amount of power for long periods. This is more common in areas where severe storms and other natural disasters can wipe out power for days at a time with no realistic hope of timely restoration.

With proper maintenance, these Primary Generators are designed to run 24 hours a day, and 7 days a week for areas where access to electricity from the grid might be unavailable for a prolonged amount of time. For example, a hospital in a known earthquake zone or a region where strong hurricanes are common might choose a high-capacity primary generator to ensure reliable power for patience and to maintain climate control for temperature-sensitive medications.

How To Choose The Right Commercial Power Generator

There are a few important factors that come into play when choosing the best commercial standby or primary generator for your property.


Determining the correct size of commercial generator you need includes several key factors. It takes more than simply adding up the wattage of priority appliances like you would when assessing the size of a residential generator. To truly determine the size of a commercial generator you need to maintain a reasonable level of service to your property, you should consult with a commercial electrician. They have the experience and expertise to accurately determine the power need for essential equipment and climate controls, as well as other factors that can influence the scale.

The Type Of Fuel

You might be surprised to hear that there are several different fuel types that a commercial generator can run on.


Readily available and often easier to resupply than some other generator fuels, gasoline commercial generators are popular. Though they tend to be less fuel-efficient than a diesel counterpart of relatively the same size and scale.


Also readily available, though not as easy to access in some places as gasoline, diesel provides a lot of power and is more fuel-efficient. Though it might not be the best option for an unsheltered emergency generator in an area that experiences severe cold.


As a byproduct of petroleum production, propane is often readily available via municipal lines. Though if you want a propane generator in an area where earthquakes are a concern, you might want to consider having a reinforced liquid propane storage tank installed on-site to ensure a long-running supply in the event that municipal lines become unavailable.

Natural Gas

The growing distribution through municipal lines and clean-burning energy efficiency makes natural gas increasingly popular for powering generators. Though it is typically only available through municipal lines, and only has a third of the energy density of propane, so a compressed natural gas storage tank might not be sufficient for meeting long-term power needs in the event of a prolonged natural disaster that cuts off access to the power grid.

The Power Phase

Single-phase electricity is typical in residential areas and provides the power necessary to operate 120/240-volt household appliances. Though a lot of larger commercial properties use three-phase power to handle heavy-duty machinery, HVAC systems, and other high energy demand equipment.

Though there are times when a single-phase generator might be sufficient for supporting a small business when the electrical grid goes down. This is assuming that the power demands will come from basic electronics and small appliances rather than heavy machinery.

A three-Phase generator is needed for most large commercial properties as well as things like manufacturing facilities, farms, and other heavy-duty power applications.