Emergency plans 'thrown out the window'
County officials had been warned about the utility shutoffs, but they didn't know they were happening until that day, said Ryan Derby, emergency services manager for Humboldt County, where Blue Lake Rancheria is located.
"Our entire planning model for the last 18 months got thrown out the window," Derby said.
Suddenly, the rural county of 136,000 people was in the dark.
"Humboldt County prides itself on being resilient," Derby said, "But I think in light of these public safety power shutoffs we realized how dependent we really are on electricity."
The county focused on residents who relied on medical devices like respirators or oxygen tanks.
At the Blue Lake Rancheria, Anita Huff was directing emergency services for people with critical medical needs.
"We had eight people here who could not have lived without electricity," Huff said. "So, we saved eight lives."
The tribe built the microgrid with help from the Schatz Energy Research Center at Humboldt State University.
"Microgrids are very complex. In some ways they're kind of like snowflakes where no two of them are the same because it depends on where you are on the grid and what your facility is," said Dave Carter, the managing research engineer at the Schatz Energy Research Center and the lead technical engineer on the project.
A power 'island'
Microgrids keep the electricity flowing to customers even after disconnecting from the overall power grid. During an outage, the Blue Lake microgrid goes into "island mode" and a large Tesla battery system stores extra power and balances the energy supply and demand.
By comparison, Carter said, conventional solar arrays have to automatically shut down during outages for safety so they don't electrocute powerline maintenance workers or people who could come in contact with a downed line.
Microgrids do come at a price. The Blue Lake installation cost $6.3 million. Five million dollars came from a California Energy Commission grant, and the tribe helped raise the rest.