With the onset of wildfire season in the western United States, the Bonneville Power Administration (BPA), the Western Area Power Administration (WAPA) and California’s Trinity Public Utilities District (Trinity PUD) recently detailed steps they are taking to help mitigate the potential of significant wildfires.
BPA earlier this month added a public safety power shutoff (PSPS) procedure to its wildfire mitigation plan, and Trinity PUD is partnering with staff at WAPA's Sierra Nevada regional office to make its transmission rights of way less vulnerable to wildfires.
While the number of acres burned year-to-date is below the 10-year average, historically low precipitation levels have raised the risk of significant wildfires to above normal, according to the National Interagency Fire Center. More than 87 percent of the western U.S. is now categorized in drought and over half the West is in the highest two categories of drought.
BPA began considering a PSPS procedure in the fall of 2020 after last summer’s Northwest wildfire season.
“This procedure is another preventative measure layered on top of world-class vegetation management, strategic asset management and risk-based planning – the cornerstones of our mitigation efforts,” BPA Administrator John Hairston said in a statement.
BPA said customer feedback helped inform the PSPS process it has put in place for the 2021 fire season. The utility also noted that taking a BPA transmission line out of service does not necessarily mean Northwest residents and businesses will lose power.
“BPA is committed to providing as much prior notification as possible to customer utilities, generators and state emergency managers, particularly when PSPS will result in service interruptions,” Tina Ko, BPA vice president of transmission marketing and sales, said in a statement.
“Because weather is one of the variables involved, our notification windows may be compressed at times,” Ko said, “however, we will do everything we can to help customers and emergency management officials plan for the lack of electricity these events can cause.”
For Trinity PUD, wildfire mitigation is taking the form of expanding power line rights of way.
The PUD is expanding the right of way of its 60-kilovolt (kV) Trinity-to-Weaverville line from 80 feet to up to 130 feet. It is also expanding its Lewiston 60-kV tap line right of way from 80 feet to up to 130 feet, and expanding the rights of way for its distribution lines from 20 feet to up to 130 feet. The expansions aim to reduce fuel loads and to create potential firebreaks.
Recent wildfires have shown that the current minimum buffer clearances are not sufficient to prevent destructive wildfires, Trinity PUD said.
Trinity PUD’s aim is to protect its transmission and distribution system through “proactive vegetation management,” which the PUD said would also “enhance the reliability of power distribution, improve WAPA transmission line access and protect the health and safety of nearby communities and biological and natural resources.”
Trinity PUD and WAPA’s systems run through areas with dense vegetation and steep terrain. CalFire has classified the area a “very high fire hazard.”
California law, specifically Senate Bill 901, requires publicly owned electric utilities to prepare wildfire mitigation measures if the utilities’ overhead electrical lines and equipment are located in an area that has a significant wildfire risk.
California PUC seeks comments on new PSPS guidelines
Meanwhile, the California Public Utilities Commission (CPUC) is seeking public comment on a proposal that would enhance and update existing guidelines and rules for utility PSPS events in advance of the 2021 wildfire season.
The proposed decision, which is on the agenda for the CPUC’s June 24 meeting, states that when utilities de-energize transmission lines as a wildfire mitigation strategy of last resort they must balance the risk of harm from utility-ignited wildfires against the public harm of shutting off power.
The proposal recommends guidelines and rules intended to augment existing directives to address some of the issues that arose during the utilities’ execution of PSPS events in 2020.
If adopted, the guidelines and rules would go into immediate effect and require annual reporting to increase transparency into electric investor-owned utilities’ (IOUs) planning and execution of PSPS events by requiring them to submit an annual pre-season report detailing actions taken to prepare for and mitigate the impacts of future PSPS events and to submit an annual post-season report providing data on customer-focused outcomes during prior year PSPS events.
To improve planning and preparation, the proposal would require IOUs to conduct annual PSPS exercises using the same procedures they would use in an actual PSPS event. The proposal would also include additional entities under the definition of “critical facilities and infrastructure” to ensure that entities essential to public safety receive advance notification of PSPS events and additional assistance in assessing the need for backup generation to ensure resiliency.