During recent wildfires, California residents with rooftop solar systems were surprised to find that when electricity from the grid went out, so did their solar system. If a homeowner’s solar system is tied to the grid, for safety reasons the solar system goes down as well—otherwise, the electricity sent into the grid would endanger power line workers making repairs.
By contrast, many solar+storage systems can automatically disconnect from the grid, allowing homeowners to continue drawing power either from their solar panels or from the battery itself. While most solar+storage systems aren’t designed to completely cut off a homeowner’s connection to the grid, they do provide the ability to act independently from the grid for shorter periods, either individually or collectively as microgrids.
When the Colonial Pipeline fell victim to a cyberattack in May 2021 and cut off fuel supplies to much of the East Coast, it sent shivers down the spines of grid operators. While the North American Electricity Reliability Corporation has mandated cybersecurity standards for the electricity grid, the grid is not invulnerable. A cyberattack briefly shut down an unnamed utility in the western U.S. in March 2019, the first of its kind.
One defense from shutdowns from cyberattacks, natural disasters, or other emergencies is the creation of microgrids. On the one hand, utility companies have less control over the operation of solar+storage systems, making them potentially more vulnerable to cyberattacks.
On the other hand, compared to a centralized energy grid where a single phishing attack can cause widespread power outages and require the payment of millions of dollars in ransom to return the system to normal, the reward to hackers for disrupting distributed energy resources like solar+storage is smaller and the damage is more locally contained.
In the United States, 1,639 microgrids were operating as of September 2020, generating over 11 gigawatts of electricity for their customers. Microgrids are especially useful for strengthening critical resources like hospitals or military bases. In 2019, a fire station in Fremont, California became the first in the United States to install a solar+storage microgrid.
What Is a Microgrid?
A microgrid is a networked group of energy producers and consumers that are normally connected to a utility’s electricity grid but can also be “islanded” to act independently when grid power goes out.