To support our customers during a Public Safety Power Shutoff (PSPS), we use microgrids to supply temporary power to some areas. Microgrids allow us to keep power on where it is safe to do so. Customers supported by these microgrids will experience one or two outages of up to four hours each.
We use two types of microgrids to provide temporary power during a PSPS, distribution microgrids and substation microgrids.
Distribution microgrids serve areas where the power lines are underground, or outside of high fire-threat areas or the PSPS weather footprint. They keep the power on for community resources, including:
Substation microgrids serve larger areas with thousands of residential and commercial customers. They’re located at substations impacted by a PSPS and operate with temporary generators instead of the substation’s usual transmission source. However, they’re only used if they serve an area that is safe to energize.
Distribution microgrids. If an area is safe to energize, sectionalizing devices are used to disconnect it from the larger electric grid. Temporary generators then provide power to the area. The generators are typically located in a space built in advance to allow for quick connection. These spaces are referred to as “pre-installed interconnection hubs” (PIHs).
Substation microgrids. If electric lines serving a substation are impacted by a PSPS, but that substation serves an area that is safe to energize, temporary generators located at the substation may be used to power homes and businesses in the area.
We send phone, text and email notifications to customers who will be impacted by a PSPS event. If you are one of those customers, your notification will indicate that your address will be served by microgrid backup power. You can also find outage details for your address using our outage map.
We use temporary microgrid power only when and where it is safe to do so.
Outages are needed to keep workers safe when connecting and/or disconnecting any power source to the grid, including microgrid backup power. This work can take up to four hours. So, depending on the type of microgrid backup power used, customers will experience a single outage of up to 4 hours when backup power is removed, or two outages of up to 4 hours hear—one at installation and the other at removal.
Yes. Microgrids provide full power to your home, just like if you are on your regular grid power.
Distribution microgrids: We target areas that can be safely energized under extreme weather conditions. We also focus on areas that have critical facilities such as hospitals, police or fire stations, and key community resources.
Substation microgrids: We target substations in areas that are most likely to experience PSPS weather and outages. They must be able to safely provide power during the PSPS based on location or circuit configuration.
We analyze historical data to determine which areas are likely to experience a PSPS but can be safely energized with microgrid backup power. The sites are selected and prepared in advance. We continue to review opportunities to expand our microgrid sites.
Currently, we mainly use diesel-powered generation for microgrid power. Cleaner burning Tier 4 engines are being utilized as much as possible, which minimize emissions and exhaust. Pilot programs for sustainable and renewable options for temporary generation are being studied.