COUNTY NEWS RELEASE
A power outage that impacted the whole townsite of Los Alamos in the evening hours of Friday, May 8, started at 9:32 p.m. with a high-magnitude fault (greater than 5000 amps) on both transformers that feed the townsite from the electric substation on Los Alamos National Laboratory (LANL) property.
While any interruption of electric service experienced on LANL property was brief, the townsite outage spanned the townsite from the far east ends of North and Barranca mesas, west toward the outer edge of the Quemazon subdivision, and then east again to the commercial and county buildings beyond the Los Alamos Airport. Electricity in the Elk Ridge neighborhood on East Jemez Road remained on because it is fed by LANL’s electric distribution system.
The root cause of the outage is under investigation. Electric Distribution Division staff from the Los Alamos Department of Public Utilities (DPU) are collecting data for review by the department’s consulting engineer. The DPU has electric lineworkers on standby 24/7 to handle power disruptions whenever they may occur. Because Friday’s incident was so significant—an outage of this magnitude is not typical in Los Alamos—additional DPU lineworkers were called in to assist.
The fault was the first clue in a cascading series of events impacting the townsite electrical grid. Residents reported seeing what appeared to be sparking or explosions atop a power pole near Trinity Drive and the Canyon View Apartments. The DPU’s crew found melted jumpers on the pole and the ground below, with the transformer still intact. Jumpers are short cables that connect electrical conductors together.
Lineworkers turned off power at the site of the jumpers and began patrolling lines. After finding and fixing one location with twisted wires, they switched focus to identify underground issues. Eventually, they found an underground cable failure near the Aquatic Center, which they believe was the source of all the failures, and then discovered damaged underground cable on Cheyenne Street as well.
The DPU does not have a true outage management system, however staff can identify and monitor meter failures through an automated metering portal. During the span of this cascading outage, 5,785 electric meters reported failures on the portal.
To improve electrical redundancy, the DPU’s highest priority electric project is construction of the Los Alamos Switch Station (LASS) on LANL property near the electric substation. The LASS is nearly complete, however installing electric cable across the canyon to the switch station has proven challenging and is the final, unfinished step. Once the LASS is complete, redundancy for the townsite will be significantly improved.
Electric reliability is tracked by the DPU using the System Average Interruption Duration Index (SAIDI) benchmark that is commonly used by electric providers throughout the country. The department aims to remain below 60 minutes on the SAIDI, meaning the average customer experiences 60 minutes or less of electric interruption throughout a rolling one-year period. At the end of April, the SAIDI for DPU was at 74. The state and national SAIDI are 273 minutes and 663 minutes respectively.
The DPU is a community-owned utility that provides electricity, natural gas, water, and wastewater services to Los Alamos County. While staff work hard to minimize outages, they’re occasionally planned for maintenance and upgrades as necessary to maintain and improve the grid. Utility customers who depend on electricity for medical equipment are reminded to have backup plans in place for unexpected power outages and are encouraged to register on the DPU’s medical alert list annually to receive advance notice of planned outages. Sign up at https://ladpu.com/medequip.