Hybrid Solution Delivers 24/7 Power While Generators Take a Break

In summer 2019, a major U.S. general contractor began constructing the first of three extensive data center campuses in Arizona. Once completed, the facilities will create jobs for mechanical and electrical engineers, data center technicians, and many others. 

Each site includes 10 buildings, with five colocation centers in each building – and four permanent 2.5-MW generators required for each one. If you do the math, that’s 20 2.5-MW generators for each building, for a total of 50 MW. With 10 buildings, a single data center will ultimately use a walloping 500 MW of power. 

Technology lowers the load on fuel-hungry generators

The contractors were aware that they’d need hundreds of diesel generators to manage the project, along with frequent refueling to keep them running. That was especially true in summer, when temperatures routinely reach 120°F in the area and air conditioners run continually. But shortly before the contractor contacted Sunbelt Rentals to order the generators, the local Sunbelt Rentals location had added a new solution to its fleet, one that would decrease the load on the generators – and provide many other advantages.

Running diesel generators at low loads is inefficient, but that’s exactly how they operate 60 percent of the time. And as long as the generator is running, it’s using fuel and kicking out damaging NoX and particulate matter and carbon emissions. Perhaps worst of all is the intense and constant noise.

Most rental equipment providers would simply provide generators without concern for the drawbacks. But not this time.

Hybrid solution keeps the lights on 24/7

The solution Sunbelt Rentals offered the contractor is the Hybrid Energy System (HES). The HES consists of high-density lithium ion phosphate batteries, industrial grade inverters, and an on-board controller. When the generator is offering, the excess power recharges the batteries. For lower loads, the generator switches off and the system changes over seamlessly to battery storage – which consumes no fuel and creates no noise. The generator restarts when the batteries are depleted or when the load is greater than the HES can support.

The contractor agreed to try the solution while constructing the data center. The HES contributes to trailer and jobsite power -- lighting at a laydown site, security check, a double-wide nurse’s station and orientation center, and a triple-wide lunch tent trailer. The HES can output 125A and is charged dynamically depending on the load. When the power meter drops to 15 percent, the generator fires up, ensuring there’s never a loss of on-site power. The HES takes only a few hours to recharge.

The contractor has non-stop power all day long to service equipment and keep computers and refrigerators working.

Savings extend to rental costs

To provide 24-hour power, the generator usually runs only 6 hours each day. This lowers the rental cost – instead of triple-shift rates to run generators continually for 24 hours, the contractor needs to pay only single-shift rates. The difference is more than enough to cover the HES rental cost. 

But the contractor also saves on fuel. Using one gallon an hour for six hours cuts fuel costs 75 percent compared with using 24 gallons each day. At $3.00 a gallon, that’s a savings of $54 for each generator each day. 

Another advantage is the Energy Control Module, an on-board computer that enables set-up and control, allows selection of incoming charge current and control of inverters, helps the operator see what mode the HES is in, and feeds the data to the cloud. The customers and Sunbelt Rentals technician can sign in to an online portal to monitor and control the HES remotely and respond quickly to any issues. The system also includes Energy Management Software designed to provide detailed information about the operation of the energy storage fleet and connected systems.

The contractor appreciated the chance to test and use a green solution to supplement their generators. Many companies are following their lead, and some electric utilities, including Arizona Public Service, now require a source of power other than a diesel combustion engine on their project sites.

With a hybrid solution that reduces fuel, emissions, noise, and cost, Sunbelt Rentals has moved to the forefront of green power in the Phoenix Valley.

The experts at Sunbelt Rentals understand that every project has unique needs and challenges. We’re available 24/7 to help customize a power solution for your next project. Give us a call at 866-704-2501 or have us reach out to you.