Napa County To Soon Have 2 PG&E Microgrids

CALISTOGA, CA — PG&E began construction began this week on the second of two microgrids in Napa County meant to provide electricity during future wildfire-related public safety power shutoffs. The downtown Calistoga location of the temporary microgrid generation site was selected through analysis of prior and expected future shutoffs, overall feasibility and related utility work in the region that could also reduce the impact of shutoffs, company officials said Friday in a news release.

The Calistoga microgrid is among several being developed this year by PG&E across its service area, according to Debbie Powell, vice president of PG&E Asset & Risk Management and Community Wildfire Safety Program.

"Our specific objective with the development of temporary microgrids is to provide electricity to resources such as medical facilities and pharmacies, police and fire stations, gas stations, banks, markets and other shared community services when weather conditions make it unsafe to operate the grid," Powell said.

The microgrid backup generation site in Calistoga is on Washington Street near Tedeschi Field — a different site than one used last year to energize Calistoga during the shutoffs, according to PG&E North Bay Spokeswoman Deanna Contreras.

The new site enables PG&E to rapidly connect mobile generators to the grid, allowing much of the downtown area — including a medical facility, fire and police station, fairgrounds, post office, banks, schools, markets, hotels, and restaurants among other businesses, facilities and community services — to remain energized during future PSPS events impacting the area, Contreras said.

The Calistoga temporary microgrid energization zone includes approximately 800 PG&E customers in the general vicinity of downtown Calistoga, Contreras said.

Weather conditions and other operational considerations prevent PG&E from guaranteeing electricity to all customers potentially served by this temporary microgrid during all PSPS conditions or scenarios, Contreras noted.

PG&E anticipates construction on the microgrid backup generation site to be completed with fully operational microgrid islanding capabilities by July — islanding meaning the ability of a microgrid to disconnect from the larger power grid.

"When the power is turned off during a broader grid outage, the area supported by the microgrid may still remain energized and can operate autonomously," Contreras said.

PG&E customers in the vicinity of the construction site will receive an automated, courtesy phone call from PG&E notifying them of the work taking place, Contreras said. The crews are required to comply with coronavirus-related social distancing and to wear personal protective equipment —PPE— when necessary to protect their health and that of the general public.

PG&E also plans to notify customers who are within the microgrid's energization zone about how it will operate during a shutoff.

Napa County's second such temporary microgrid is in Angwin.