Some Insights on Island’s Hometown Power Supply
In light of recent events in the North Bay: wildfires likely sparked by electric equipment, public saftey power shutdowns (PSPS) and other activities by Pacific Gas and Electric Co. (PG&E) spurred several Alamedans to contact the Alameda Sun with questions related to the City of Alameda’s proprietary electric utility, Alameda Municipal Power (AMP), founded in 1887.
According to AMP spokesperson Kathleen Haley, AMP has responsibility for maintaining the electric equipment in Alameda.
“As part of AMP’s system maintenance programs, we regularly patrol our circuits to ensure overhead line clearances are adequate and meet regulatory requirements,” stated Haley in an email. “Overall, AMP’s electric system is maintained according to regulatory requirements, manufacturers’ recommendations and prudent engineering assessment and practices.”
AMP also employs the services of an arborist for tree maintenance and has a regular tree-trimming program in place.
The relationship with PG&E
AMP owns and operates the distribution system inside Alameda. Entities such as PG&E control the larger transmission grid, outside of AMP’s jurisdiction, which is controlled by the California Independent System Operator (CAISO). The electricity produced at generation sources is carried over those transmission lines to Alameda. Some portions of these transmission lines may run through high fire-threat areas and be subject to shut-offs, according to Haley.
If transmission lines in a specific area of Northern California are de-energized by PG&E and CAISO, “AMP has engineered its electric system to be redundant and has developed contingency plans to ‘switch’ to a different set of transmission lines, thereby reducing the likelihood of rolling blackouts or power shut-offs in Alameda,” stated Haley. “Should one of AMP’s generation sources become impacted, AMP has the ability to obtain supplemental energy resources, which also reduces the likelihood of a power shut-off affecting Alameda.”
Haley also explained that while power is generated on the Island, which might be helpful in supporting the grid, AMP is not able to disconnect from the wider grid and run independently as a microgrid.
The city’s storm and sewer-pumping facilities are maintained by the city’s Public Works (PW) department. Some pumps have stationary, back-up generators on site while the rest are equipped for portable, plug-in generators. PW performs monthly maintenance checks and refuels the generators to ensure their performance as a back-up power source during a power outage. Power for the water supply in homes and businesses is under the jurisdiction of East Bay Municipal Utilities District.
When would AMP shut down?
According to Haley, utilities are required by law to develop a wildfire mitigation plan if there is a significant risk of catastrophic wildfire resulting from electrical lines and equipment in their service territory. Alameda is located in a geographical area classified as a Tier 1 by the California Public Utilities Commission (CPUC) Fire-Threat Map, which means it has an extremely low likelihood of utility-associated wildfire threat.
AMP’s generation sources are outside of the boundaries of AMP’s service territory and managed by the Northern California Power Agency (NCPA). NCPA and associated organizations have the responsibility to address wildfire mitigation requirements for power resources and related infrastructure.
“The potential for a public safety power shut-off in Alameda really comes down to the transmission lines carrying AMP’s electricity to the city,” stated Haley. “Some of these transmission lines may run through high fire-threat areas, and it is possible PG&E and CAISO could determine it’s necessary to de-energize them. AMP has contingency plans in place to power the Island in the event one transmission pathway is affected and will discuss this in advance with PG&E. If it looks as though none of the transmission pathways is available to AMP, we may need to announce a PSPS.”
Should it become necessary to issue a PSPS in Alameda, AMP, City of Alameda and the police and fire departments will use all available channels to communicate to Alamedans as quickly as possible. When possible, PG&E will aim to notify AMP 24 to 48 hours prior to a shut-off and immediately before it. After the extreme weather is over, the lines will be inspected before power is restored, according to Haley.