PG & E to conduct test of Humboldt Bay Generating Station

On Saturday, May 9, 2020, PG&E will conduct a test that represents another significant step toward being able to provide power to many Humboldt County residents directly from the Humboldt Bay Generating Station (HBGS). Known as “islanding,” this will allow portions of Humboldt County to be separated from the larger “grid” and energized exclusively from HBGS during a Public Safety Power Shutoff (PSPS) event in other parts of the state.

Although PG&E does not foresee any disruption in customer service during the testing, it is possible a short duration outage could occur in areas from Eureka south to Scotia, the area which will be tested on Saturday.  The area does not represent the entire area that would be islanded during a PSPS event upon successful completion of the project. That is approximately 66,000 meters across much of the county.

We will have protocols in place to ensure power is restored within an hour should an outage occur. We are asking customers to prepare for a potential outage as they normally would when a winter storm hits the North Coast.

The testing will begin at around 7:00 a.m. Saturday and last through approximately 3:00 p.m.  Additional steps will be needed after the test before HBGS is fully ready to be islanded.

Once fully completed, this islanding will represent a significant milestone for our customers in Humboldt County. We have made much progress in supporting our customers and local communities to keep much of Humboldt County energized during PSPS events and winter storms. Islanding HBGS can help us provide local power when transmission service is lost to the area for any reason. To make that happen, here is what PG&E has done so far.

Completed low-load testing of HBGS engines required to adjust load as needed
Received air permit variance to test in island mode, valid through June 30, 2020
Completed modifications to engine controls at HBGS
Completed modifications to emissions controls at HBGS
Creating plant operating procedures and training plant operators
Developed operating procedures and system settings
Completed modifications in the field

We will continue to fine-tune the system based on the test results and are making additional transmission upgrades to improve functionality and provide more options for various unplanned “island” scenarios.

Depending on whether issues surface during this testing, and our subsequent work, we are on track to confirm HBGS’ islanding capability by the end of May.

The sole purpose of a PSPS is to reduce the risk of catastrophic wildfires during severe weather.  PG&E’s goal this year is to reduce the number of customers affected by each potential PSPS event by nearly one-third, compared to a similar weather event last year.  The islanding work at Humboldt Bay Generating Station is an example of that work.