Critical Infrastructure: Solar carports anchor microgrids at facilities that need them most

RBI Solar carport Montgomery County
This carport at a city building in Montgomery County, Md., was built by RBI Solar.

Solar carports, or canopies, are becoming a dual-purpose component of more microgrids that protect critical services locations from grid shortcomings. While both carports and microgrids individually have long been gaining ground among adopters, the combination of the two enables more site-constrained critical facilities to add solar reliability to microgrids, especially where little open ground exists for standard ground-mounted solar solutions.

The basic purpose of a microgrid is to island the user facility — be it a hospital or fire station — from the utility grid when brown-outs or black-outs are at play (which are becoming more common). While the regulated utilities claim a need for state approval for billions of dollars worth of grid improvements to avoid these outages — both planned and unplanned — such improvements, if approved, are not likely to be evenly distributed.

Utility grid “investments are unlikely to be made in areas with low population density but that are likely high risk for outages. This type of situation could be aptly addressed by DER (distributed energy resources), within microgrids or as standalone resources,” observes a February 2021 report from the California Energy Commission on DER planning.

The paired solar carport + microgrid solution is finally coming of age. “We now have some decent traction with solar carports and microgrids for critical services, including hospitals, fire stations and water plants,” says Raphael Declercq, executive VP of distributed solutions at EDF Renewables. “We also see the potential for the use of EVs for vehicle-to-building solutions. In a few years, there will be some bi-directional charging with EVs that can smooth the load at home, or in a building, as a resource on top of a backup stationary battery.”

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EDF defines microgrids as “innovative systems that integrate batteries, renewable generators, load control and traditional onsite generators with intelligent componentry to create a system that ensures continuity of operation during power outages.”

The integration of EVs to solar carport microgrids may come to be the tail wagging the dog. “Solar carports are now part of the integrated solution for greenhouse gas reduction,” Declercq says. “Carports and microgrids hit the bull’s eye for resiliency even before popular talk emerged about the goal of reducing climate change.”

State mandates foster adoption

State mandates for microgrids have helped blaze the trail for solar carport installations being added to the mix. Over the past few years, microgrids have gained traction among utilities, commercial customers and local governments, according to a September 2020 report from Guidehouse Insights, by Jared Leader, the manager of industry strategy at Smart Electric Power Alliance (SEPA), and Peter Asmus, research director at Guidehouse Insights.

The authors identified 1,639 microgrids in the United States, representing 11,496 MW of total capacity. “Given the anticipated increased frequency of natural disasters due to climate change, the value of microgrids as a resilience solution is growing,” the authors opine. “Over the past few years, policy makers in the U.S. — especially on the West Coast, Hawaii and Northeast — have proposed (and often enacted) legislation promoting microgrids. All told, lawmakers in 18 different states have proposed or enacted 112 bills over the past 5 years.”

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For example, in 2018, the California Energy Commission approved $72 million for microgrids including systems for state military bases, ports, Native American tribes, and disadvantaged communities, among other locations. Funding for the grants come from the Electric Program Investment Charge (EPIC), which taps customer charges levied by the state’s three investor-owned utilities, Pacific Gas & Electric, San Diego Gas & Electric and Southern California Edison.

Medical facilities

Hospitals and other medical facilities are a primary target for solar carports + microgrids. One medical facility to recently adopt solar carports is the Department of Veterans Affairs at the Biloxi VA Medical Center in Biloxi, Miss. The system includes a 550-kW solar PV parking canopy, and a separate PV parking canopy for electric service vehicles, developed by Hannah Solar Government Services.

Similarly, M Bar C Construction recently installed a 412-kW solar carport at Vista Community Clinic, north of San Diego. The system consists of five solar carports installed throughout ground-level parking, as well as a full-cantilevered solar carport installed atop an existing parking garage.

Larger solar carports also are becoming more mainstream. For example, KDC Solar recently turned on a massive 1.6-MW solar carport at CentraState Medical in Freehold, N.J. The new system will generate approximately 2.1 million kWh of solar electricity per year, which covers 70 percent of the campus, the highest percentage of solar electricity of any hospital in New Jersey.

Fire and police stations

Fire stations typically have little extra ground space for fixed-tilt or single-axis solar, but they do have limited parking space ripe for solar carports.

Mass.-based Cape & Vineyard Electric Coop is planning microgrids for four fire stations, including some solar carports, within its jurisdiction covering 20 towns in state. The plans for the district include integrated EV charging, and solar carports may be extended to a water treatment plant and to golf courses.

In the same way, the city of Portland last year voted to adopt a fire station microgrid with financial support from Portland General Electric (PGE). The system consists of a 30-kW solar array, a 30-kW/60-kWh battery bank, and a 125-kW diesel generator, with a microgrid controller designed by Ageto.

The City of Woodland, Calif., adopted a solar carport for the city police headquarters, developed by PCI Solar, that is expected to generate approximately 636,012 kWh per year.

Maritime projects

Maritime ports, too, are a type of critical service infrastructure where solar microgrids are being adopted that have ample open parking lots. The Port of Long Beach is adopting a $7.2 million microgrid project including a solar carport, energy storage systems and advanced system management controls at the port’s security headquarters. The solution may spread to other state ports through the cooperation of students at the University of California at Irvine’s Advanced Power and Energy Program, which will analyze a year’s worth of data from the project.

Charles W. Thurston is a contributor for Solar Builder.

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