The California Public Utilities Commission (CPUC) recently approved Pacific Gas and Electric Co.'s (PG&E) comprehensive and cost-effective microgrid proposals. These are designed to reduce the number of customers affected by Public Safety Power Shutoff (PSPS) events and mitigate the impacts to those who remain affected. A PSPS may be used when severe weather threatens a portion of the electric system and the PG&E determines it's necessary to turn off electricity to reduce the risk of catastrophic wildfire.
With the increased wildfire threat in California, the PG&E is enhancing and expanding its efforts to reduce wildfire risks and keep its customers and communities safe. High temperatures, extreme dryness, and record-high winds create conditions where any spark at the wrong time and place could lead to a major wildfire.
The PG&E's Community Wildfire Safety Program includes short-, medium-, and long-term plans to make its electric system safer. These plans include installing new grid technology, hardening the electric system, and performing enhanced vegetation management, all with the goal of making PSPS events smaller in size, shorter in length, and smarter for customers. Microgrids are one tool in these efforts.
"As the PG&E continues its enhanced and expanded efforts to reduce wildfire risks, we are also working to reduce the scope, duration, and impact of future PSPS events. A key piece of this strategy is developing and deploying microgrids," said Andy Vesey, utility CEO and president.
Temporary Generation Microgrid Solutions
For 2020, the PG&E's microgrid solutions focus primarily on building grid resilience and keeping the power on for customers in communities that have a high likelihood of experiencing a future PSPS event. To that end, the PG&E has reserved more than 450 MW of temporary mobile generation to be deployed in four ways detailed below, each with an objective:
- Substation microgrids: The PG&E will use temporary generation at safe-to-energize substations to support safe-to-energize customers and communities affected by transmission line outages during PSPS events. It is preparing 63 substations to be ready to connect temporary generators as need arises during PSPS events, subject to operational logistics and generator availability. In addition to temporary generation, in certain instances, the PG&E will leverage existing local, permanent generation sources to power safe-to-energize substations and customers during PSPS events, including its Humboldt Bay Generating Station and a third-party owned natural gas plant in Red Bluff, California.
- Temporary microgrids: The PG&E will serve designated areas like "main street" corridors by rapidly isolating them from the wider grid and re-energizing them using temporary generation during an outage. These temporary microgrids will be used in selected communities where the PG&E can safely provide electricity to centrally located resources such as medical facilities and pharmacies, police and fire stations, gas stations, and banks. Construction is underway at four temporary microgrid generation sites and the utility anticipates having 10 sites ready to energize by the end of 2020.
- Backup power support: The PG&E will deploy temporary generation on an as-needed basis to critical customers for whom the failure of existing backup power would directly or indirectly affect public safety. Deployment would be dependent on generator availability and subject to operational considerations. Additionally, the PG&E has worked closely with the California Hospital Association and Hospital Council of Northern and Central California to identify hospitals supporting the COVID-19 response effort that have a higher likelihood of experiencing a PSPS event. The utility is developing grid-based solutions where possible and supporting hospital readiness and resiliency planning, to ensure that those hospitals remain energized in a PSPS event.
- Community Resource Centers: The PG&E will provide Community Resource Centers to support customers and communities affected by PSPS events. Some of these facilities may need temporary generation in order to give customers a climate-controlled location where they can charge devices and receive refreshments. The PG&E remains flexible with CRC deployment plans to adjust to the COVID-19 restrictions and best practices.
Community Microgrid Enablement Program
The CPUC also approved the PG&E's new Community Microgrid Enablement Program in which the PG&E will partner with local communities to identify and build multicustomer microgrids serving local critical facilities and/or customers with disabilities or functional needs that are not already served by other microgrid solutions offered by the PG&E.
The program will help communities design microgrids by providing enhanced technical support, improved access to relevant utility information, financial support for qualifying projects, and tariffs to support the accounting for the flows of services, energy, and costs among the parties. The PG&E will refine the eligibility criteria and other program requirements through consultation with local governments and communities, with a goal of full program implementation and projects in development by November.
The PG&E intends to model future community microgrid projects on the Redwood Coast Airport Renewable Energy Microgrid project, a collaboration between the PG&E, the Redwood Coast Energy Authority, Schatz Energy Research Center at Humboldt State University, Humboldt County, and Tesla, Inc., among others. This front-of-the-meter, multicustomer microgrid project featuring photovoltaic (PV) solar paired with battery energy storage is on schedule for commissioning and full operation in December 2020.
The Redwood Coast microgrid will provide renewable energy for 18 customer accounts, including the Arcata-Eureka Airport and the U.S. Coast Guard Air Station, and serve as a lifeline for Humboldt County in the event of a natural disaster or other emergency. The microgrid will be capable of disconnecting from the broader grid (island mode) and operating as an independent, PG&E-operated grid segment during a power outage.
"We've engaged with a variety of stakeholders on these important efforts and we look forward to continuing to coordinate and collaborate with interested customers, communities, local agencies, and governments to implement microgrid solutions that build resilience and meet specific community needs," Vesey said. "While the PG&E's temporary generation program is currently focused on 2020, our work to make the grid safer and more resilient will continue well into the future. Partnering with our communities on customized microgrid solutions for the long term will be critically important."
For more information on the PG&E's wildfire safety and PSPS mitigation efforts, visit here.