When a small aircraft crashed into a transmission tower near the Palo Alto Municipal Airport on the morning of Feb. 17, 2010, the lights went out in Palo Alto and stayed that way for the next 10 hours.
The crash killed all three of the plane's occupants and devastated the East Palo Alto neighborhood where the aircraft landed. It also served as a startling reminder to Palo Alto's utility officials and emergency responders of how fragile the city's power supply really is.
Palo Alto continues to receive power through a single electrical transmission line. While the city has been exploring plans to add a second line for several years, the initiative has proceeded at a snail's pace, marred by negotiations, studies and uncertainties.
In the meantime, Palo Alto officials are considering a new way of dealing with the potential loss of power. The city's Office of Emergency Services has recently partnered with the nonprofit Clean Coalition to develop a "microgrid" at Cubberley Community Center, the sprawling south Palo Alto campus that could potentially serve as an emergency shelter during a major disaster. Cubberley already has solar panels installed. Now, Clean Coalition is scoping out batteries that would be capable of storing the solar energy for use during an emergency.
Craig Lewis, executive director of Clean Coalition, told the Weekly that once a battery is added to Cubberley, the center will have "indefinite power backup."
"We're sizing the battery and the solar in such a way that we can provide backup to the critical facilities at the emergency shelter and to the communication infrastructure in Cubberley," Lewis said.
The microgrid project, Lewis said, illustrates the advantages of having locally generated solar power. Transmission lines, he noted, are "highly vulnerable" because one problem anywhere along the transmission line can completely take out the power load.
"Having local energy generation is going to provide resilience in a way that central generation can never do," Lewis said.
As an example, he points to Long Island, New York, where Hurricane Sandy ravaged the utility infrastructure in 2012, leaving some areas without power for several months. Clean Coalition has been working with other stakeholders on what's known as the Long Island Community Microgrid Project. Based in East Hampton, the project will rely on local renewable energy sources to provide at least 25 percent of the area's electric supply, significantly reducing its reliance on the transmission grid.
Lewis noted that when Sandy hit, Long Island looked to diesel generators for backup power. Half of them didn't turn on because they weren't maintained properly. Of those that did, about half got flooded and shut off. That left only about a quarter of the generators, with some of them running out of fuel in the weeks after the natural disaster, Lewis told the Weekly.
So when Palo Alto officials were considering earlier this year drastically reducing the rate that the city would pay for locally generated solar energy, Lewis and other proponents of local solar were quick to step in and argue against the change. Weigh the price of locally generated solar (which is currently about 16.5 cents per kilowatt hour) with that of transmitted solar (about 3.68 cents per kilowatt hour) is a "terrible comparison" because the latter doesn't offer the community the benefit of resilience, Lewis told the City Council on March 21.
The council ultimately agreed, with Councilman Marc Berman stressing the importance of "making sure we have the minimum amount of locally generated power if the grid were to go down."
Microgrids like the one in Long Island and at Cubberley could become more common in Palo Alto if the cost of developing local solar projects goes down, as Lewis believes it will, and more property owners will start participating in Palo Alto CLEAN, the city's nascent solar-energy sell-back program (Read "Palo Alto doubles down on solar energy").
Microgrids are by no means the only alternative for providing backup power. But from Lewis' perspective, they are among the most effective and reliable, particularly when compared with natural gas. He pointed to a recent study conducted by San Francisco that evaluated the impacts of a magnitude-7.0 earthquake on power losses. The analysis showed that it would take about three days to restore power to 80 percent customers using an electrical power source. With natural gas, it would take longer than three months. There is a simple reason, he said, why solar-powered microgrids are effective.
"The sun will come up every day," Lewis said. "If you can see, then there are photons hitting the earth and generating electricity."