Whether your project is in the middle of a city or hundreds of miles from the nearest one, gaining access to temporary power for your construction site is an early critical step. Electrical demands can quickly grow as trailers, light towers and heating or cooling equipment is added.

The question of how to get temporary power for construction projects before a connection to the power grid is established has many possible answers. Unless you can spend the time and money to install temporary utility power poles, most of those answers involve generators, which are the most common solution. However, alternative energy sources are sometimes an option, as are construction power banks.

If you’re at the point in a project where the jobsite is connected to the grid and the power goes out, you may also need generator backup to help keep your project on schedule.

Generators for temporary power: portable, towable and industrial

The size, location, and stage of the project will dictate your generator needs. Small to medium projects may require a mix of portable and towable generators to power trailers, power tools and the like, while larger, energy-intensive sites such as high-rise towers or mining installations may require the output of industrial generators.

Portable generators: versatile and easily moved

Portable generators are an ideal temporary power supply for construction sites in need of a versatile solution that’s easily moved from one spot to the next. Power output typically corresponds with size.

This rugged 2.9kW inverter generator, easily carried by one or two people, can run for up to five hours on a tank of gas and is ideal for powering tools such as compressors, grinders and fusion welders. Larger portable generators, such as this 5.4kW inverter model, come mounted on a wheeled cart and can provide power for multiple tools, equipment or light towers or act as a backup power supply in the event of a power outage.

Towable generators: More power but still mobile

Towable generators, convenient for larger or longer-term jobs, can be hitched to any truck and moved where needed throughout a jobsite. Some rental units come already mounted on highway-legal trailers. In addition to having multiple outlets and voltage controls, many towable generators feature large fuel tanks, which enable longer continuous operation.

Models range from the small and nimble, such as this 15.2-23.2kW generator, to 300kW towable generators.

If you’re working in an area with noise limits, look for a model with sound attenuation for quieter operation. Two-wheeled trailers work better on uneven terrain than four-wheeled, so choose carefully depending on the jobsite terrain.

Industrial generators: Maximum power for the biggest projects

Industrial generators offer far greater capacity than towable generators and are suitable for powering an entire large construction site or a mining operation. A semitrailer truck may be required for delivery.

Models include this 2000kW mobile industrial generator, capable of running nearly 10 hours at maximum load on a single 1,250 gallon tank of diesel, as well as giants capable of outputting over a megawatt at 75% load for nearly 24 hours.

Due to their large fuel demands, industrial generators are often paired with high-capacity portable fuel tanks.

Solar panels

If your construction site is too remote for easy access to gas or diesel fuel for a generator, you may want to consider a solar installation. Mobile photovoltaic installations offer silent operation and, when paired with a DC-to-AC inverter, they can power a wide variety of tools and equipment.

Models range from 12 panels mounted on a 24-foot trailer and capable of generating 4kW to 24 panel arrays mounted on a rugged, 30-foot trailer and capable of producing over 8kW. For sites with intensive energy needs, multiple trailer-mounted arrays can be leveraged to meet the demand.

Construction power banks

Industrial power banks are mobile batteries that can be integrated with a solar array, a generator or both for a more sustainable temporary power solution.

The POWRBANK system offered by United Rentals can deliver 40kW to 60kW of power and provides between 60kW to 120kw hours of storage. When it’s paired with a generator, the unit will switch the output load between the generator and stored energy as is most efficient. This reduces generator run-time, which saves fuel, reduces emissions and diminishes noise on the jobsite. Recharging typically takes three to four hours.

Generator backup: When you need a backup power supply

In addition to providing a temporary power supply for construction site needs, generators and power banks also double as backup power sources in the event of a power outage once the site is connected to the grid.

What is the best backup source for a power outage? That depends on your power needs.

To figure out what your jobsite requires to weather an outage, identify the equipment critical to keeping the project running. If you plan to rely on generators for a power outage, use this step-by-step formula for generator sizing to help you determine the best portable units to have on hand. Add an additional 10% of capacity as a safety margin.

Generators can be a convenience or a critical asset when you lack access to grid power. They can be complex and you should always consult with an expert regarding the specific circumstances, applicable rules and regulations related to your site and to your situation.

Contact our Power & HVAC experts for help in finding the right temporary power solutions for your jobsite.