TRUCKEE, Calif. — Truckee Donner Public Utility District is urging customers to be prepared for the possibility of prolonged power outages as we officially enter wildfire season in Truckee and across the region. 

NV Energy and the district both take actions during wildfire season to help mitigate wildfire risk to the community, but these safety programs can result in both anticipated and unplanned electric power outages. 

Unplanned Outages: Recloser one-shot operation

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The district’s electric utility took steps last week to reduce the risk of TDPUD electric equipment starting a wildfire. One key safety practice is to disable circuit protection devices called “automatic circuit reclosers.” A recloser is an automatic switch that is programmed to open or stop the transfer of energy, after sensing a fault. 

Most times when a power line experiences a fault, it is due to something temporary, like a branch blowing into the line, trees shedding snow, or animal contact. When a fault triggers the recloser, it waits a set time and then closes, or restarts transmission, to test the line. If the fault is gone, the recloser stays closed and there is no extended outage but the customer may experience a brief outage or “blip.” If the fault still exists, the recloser will stay open, transmission will halt and an outage will occur.

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While reclosers have greatly improved the district’s electric system reliability, they have the potential to contribute to wildfire ignition when a branch remains in contact with a line during the re-energization process. During wildfire season, TDPUD disables this capability for the recloser to reset itself, in the interest of safety and preventing electric equipment from causing wildfires. 

This is called “one-shot,” meaning that once a line experiences a fault, an outage will occur until TDPUD crews can visually inspect the line and determine the cause of the fault before putting it back into operation. It is important to note that the safety protocol of implementing a “one-shot” configuration doesn’t increase the number of faults. However, due to this safety practice, we will experience outages with longer durations to allow for physical inspections of circuits during wildfire season, which is generally June through November.

“This is about public safety and being prepared for more and prolonged power outages due to elevated wildfire risks,” said Joe Horvath, TDPUD electric utility director and assistant general manager. “TDPUD’s goal, for all wildfire safety power outages, is to restore power as quickly and safely as possible and to make sure everyone has the opportunity to be as informed and prepared as possible.”

Anticipated outages

NV Energy’s program to turn off power transmission to Truckee due to extreme fire danger is again a significant factor in wildfire season power outages. TDPUD does not generate power locally and is dependent on the transmission of electricity from our generation sources through the NV Energy system. NV Energy will continue its wildfire safety de-energization program referred to as public safety outage management, where, much like the PSPS outages that take place in many areas of California based on catastrophic wildfire risk, NV Energy will de-energize transmission lines that deliver power to Truckee during extreme weather conditions and elevated fire risk levels.

The PSOM outages — based on the length of the extreme wildfire danger period and the time required to visually inspect 100% of the electric system to safely restore power — will likely impact TDPUD’s entire customer base for periods ranging from one day to a few days.

Unfortunately, the district does not have control over the timing and duration of the outages. TDPUD is collaborating with local emergency response and critical infrastructure stakeholders to raise awareness of the NV Energy PSOM program and to mitigate impacts.

Details on NV Energy’s PSOM program and its impacts on TDPUD customers can be found at http://www.tdpud.org/psom.

Stay informed during wildfire season

The district’s ability to communicate with customers and visitors during outages is key to making sure the community is well-prepared for these events. TDPUD is asking customers to confirm their contact information and sign up for automated alerts via text or email by visiting http://www.tdpud.org and clicking on My Account.

From there, district customers can sign up to be notified of PSOM’s and other emergency situations. If a PSOM is anticipated due to extreme fire danger, TDPUD will attempt to notify all customers between 24-48 hours and 4-12 hours before the outage. District customers and the public can also sign up for TDPUD emergency Nixle alerts by texting TDPUD to 333111.

“TDPUD’s number one priority is keeping the community safe and making sure that our customers and partners are aware and informed of the potential for wildfire season power outages,” said Brian Wright, TDPUD general manager. “It is important that our customers provide us with accurate contact information and sign up for alerts. We are also working with over 30 local agencies to keep everyone up to date.”

For more information on fire safety, visit http://www.tdpud.org/wildfire-safety.To contact TDPUD, visit http://www.tdpud.org or call 530-387-3896.

Source: TDPUD