More than 1 million Californians were left in the dark for days recently as their big utility companies shut off power for fear of sparking wildfires. Frustrated by those outages, some homeowners say they’d like to turn their backs on the companies in favor of smaller providers who might do a better job of keeping the lights on. The mayors of San Francisco and San Jose say they want to sever ties with Pacific Gas and Electric, which serves much of Northern California, and create separate utilities for their cities.
Grasping for solutions, people toss around ideas like joining “microgrids” or setting up banks of generators to keep the electricity flowing during widespread power cutoffs. Would that really help?
What, exactly, is a microgrid?
A microgrid can be as simple as a single home operating on its own solar power, or a complex series of connections between a power source and distribution lines to end users. It can run a business, a neighborhood or even a city. It can be any size and may be fueled by renewable energy stored in batteries, or by generators run on a conventional fuel such as diesel.
Here’s Chris Marnay, a senior scientific fellow at Lawrence Berkeley National Laboratory, who wrote the definition of microgrid that is used by the U.S. Department of Energy: “There are two characteristics: It is a locally controlled system, and it can function either connected to the grid or as an electrical island.”
How many microgrids are in California?
It’s difficult to say how many have sprouted across the state and are now dotting the landscape, producing and sharing their own energy. Such systems include small neighborhood operations and one that runs the desert town of Borrego Springs.
That town, and others like it, are known as end-of-the-line communities, lying just beyond the reach of power companies’ distribution lines. For those small locales, and for residents in many rural parts of California, a microgrid is the only choice if they want power.
Many state universities have training-wheels versions that use small solar arrays to power a building or a section of the campus. UC San Diego runs a much larger system that provides up to 90% of campus electricity.
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