This 26-MW solar array was used with batteries and diesel generators in a large microgrid demonstration in Southern California. Pacific Gas and Electric Co. is seeking 20 such microgrids in Northern California by next June.
In an effort to keep its Northern California customers' lights on during widespread precautionary blackouts to prevent power lines from sparking wildfires, Pacific Gas and Electric Co. has launched an unprecedented search for microgrids.
Heavily criticized for cutting power to millions of its customers in October, and under Chapter 11 bankruptcy protection with its parent company, PG&E Corp., related to a series of deadly and devastating blazes in 2017 and 2018, the embattled utility is seeking offers for community-wide microgrids to come online in 20 select areas by the 2020 wildfire season.
Proposals for third-party or utility-owned systems are due Jan. 15, 2020, according to a request for offers issued earlier in December. "Rapidly-deployable resources" may include renewables, fossil fuels and batteries. Pacific Gas and Electric, or PG&E, wants the systems operational by June 1, 2020, but said it will also consider offers for projects up and running by Sept. 1, 2020, ahead of peak wildfire season.
The total capacity associated with these systems, nearly 520 MW, is more than all 419 MW of microgrid capacity installed in the United States in 2019, as identified in a recent report from Wood Mackenzie. If realized, PG&E's plan would roughly double the consulting firm's 2020 forecast and invigorate the nation's slow-moving microgrid market.
PG&E is looking to cover the electric demand of all customers at the 20 substations where they would connect, implying systems sized from 4 MW to nearly 70 MW. That would enable the utility to energize thousands to tens of thousands of customers per substation for days at a time during transmission line outages. Developers must design the systems so that distribution lines served by those microgrid-powered substations can remain safely in operation.
"It's huge," Craig Lewis, executive director of the Clean Coalition, a California-based group promoting community microgrids, said of the solicitation. "That's a sign that PG&E is doing the right thing."
When not providing power during blackouts, PG&E wants to use the microgrids to provide resource adequacy, energy and ancillary services to the California ISO. The utility has proposed to count its massive microgrid deployment toward the nearly 717 MW it must procure in line with a recent California Public Utilities Commission order. Regulators in November required energy suppliers to bring online 3,300 MW of new resources by 2023 to stave off a potential capacity shortfall.
The communities where PG&E is seeking microgrids are among those hit by recent wildfires and crippling blackouts.
While the scale of PG&E's search is unparalleled, another California utility already has demonstrated that such large-scale microgrids can work.
In Borrego Springs, Calif., San Diego Gas & Electric Co. has demonstrated a microgrid — consisting of a 26-MW solar farm, 3 MW of rooftop solar, two diesel generators, three battery systems and an ultracapacitor — to power the town through planned and unplanned outages.
PG&E has been exploring microgrids on a smaller scale ahead of its new request. One project already approved and scheduled for construction in 2020 is the Redwood Coast Airport Renewable Energy Microgrid. A collaboration with Redwood Coast Energy Authority will create a microgrid circuit owned by PG&E to power commercial and U.S. Coast Guard airports and around 20 other customers in Arcada, in Humboldt County, through outages.
The network will feature a 2-MW front-of-the meter solar array, 8 MWh of battery storage, 250 kW of behind-the-meter solar and demand response from electric-vehicle charging. The California Energy Commission helped to fund the project in part to explore how to push the state's microgrid market to the next level, in line with a 2018 state law.
"This is the nation's most ambitious microgrid," said Lewis, a technical adviser on the project, noting that participants are creating experimental tariffs and agreements that can be applied to future projects throughout the state.
As public safety power shutoffs drive momentum, local governments and public agencies are eager to explore their options. The Clean Coalition, which recently completed a feasibility study on six microgrid sites for the city of Calistoga, on Dec. 18 announced it is working with Sage Energy Consulting on a proposal for 18 microgrids at schools in the Santa Barbara United School District that would rely on solar, energy storage and electric-vehicle charging.
Depending on the outcome of the study and an affirmative decision from the school district, the project partners hope to sign a long-term contract with a developer by June 2020.
"I think the writing is on the wall that we are going to move forward in this microgrid world," Lewis said.