Generators for Construction: How Much Power Do You Need?

If you're a construction contractor, there's a good chance you'll need to rent a generator at some point. Generators provide electricity for tools, equipment and lighting at remote sites that don't have access to the power grid. They can also provide emergency backup power when an outage occurs, minimizing the risk of costly downtime.

When you're looking for the best job site generator for your construction projects, you'll discover that they come in a wide variety of sizes, configurations and power output capacities. It's important to select a model that provides sufficient power to keep your site running, but not so much that you end up wasting electricity — and money.

Factors to Consider When Selecting a Generator for Construction

As a rule, you'll want a generator that provides enough power for your site when operating at 70-90% capacity. A generator that runs at less than 50% of its capacity creates a situation called "wet stacking," which significantly reduces the unit's operating efficiency.

Taking the following factors into account can help you determine the proper size and output capacity for your generator rental:

  • Site size: As you might guess, the larger the size of your construction site, the more power you'll need your generator to produce. Bigger sites may require several generators to meet the power requirements.
  • Equipment types: If your construction job demands the use of heavy-duty equipment and tools, you'll need a generator with more wattage than when using smaller products that consume less electricity.
  • Reserve power: Some pieces of equipment require more electricity to start up than they do to operate. Make sure you choose a generator that can accommodate power surges that may occur when starting several machines or tools at once.
  • Voltage capacity: Along with a generator's wattage, you should also consider the voltage it can provide. The higher the voltage output, the stronger the electrical current the generator will deliver.
  • Phase: Generators come in single and three-phase options. For a construction project, you'll likely need the latter version, as it will deliver a more stable and reliable power supply.

A simple way to calculate the best job site generator size for you is to add up the wattages of all the equipment and tools that require electrical power. You can then compare this total with the wattage of the generators that are available for rent. Be sure to choose a model that offers a little extra capacity to account for power surges and the possible addition of more equipment during the project.

Get Help Choosing the Right Generator for Construction

The Cat® Rental Store carries an extensive inventory of portable generators for rent at competitive rates. We also have the expertise to help you select the best job site generator for your power requirements.

Feel free to browse our current generator lineup. Give us a call at 1-800-RENT-CAT or check in with your nearest location for more information and tips on choosing a model — we're available around the clock to assist you. To request a fast quote, please fill out and submit our online contact form.

Find The Cat Rental Store Near You