High-flying maintenance another way SMUD is keeping its system safe and reliable
SMUD’s high-voltage transmission lines that traverse the Sierra deliver large amounts of power from SMUD’s hydroelectric facilities to SMUD customers in the valley. Critical to the lines’ capability are the splices that enable the lines to be continuous. As transmission lines are strung or repaired over time, the splices—tubular metal sleeves that connect long sections of conductor—can degrade and fail. A fault can significantly impact the electrical system, potentially leaving thousands of customers without power. Failure of splices can also lead to unsafe situations especially if a line would separate and fall.
To find potential faults, a SMUD lineworker suspended in a chair connected by a long tether to a helicopter uses state-of-the-art portable X-ray photography to inspect these major transmission lines that feed the SMUD grid. Simultaneously on the ground, a crew looks at the live X-ray pictures and data being collected and can identify any potential problem immediately and assign it for prompt repair to prevent future failure. SMUD has been using the technology for several years. This year’s work covered a huge section of transmission lines from Folsom to Pollock Pines.
“This work is part of our ongoing year-in, year-out maintenance to harden the SMUD grid,” said SMUD Chief Energy Delivery Officer Frankie McDermott. “This tool enables us to see issues that could lead to line failure and power outages, or worse, a compromise in the safety of our infrastructure which we dutifully work to prevent.”
These high-voltage lines are strung atop high lattice-style towers. Maintenance and repairs on them can involve a lot of work, sometimes more than one hundred feet above the ground.
The work is part of many ongoing SMUD grid projects to improve and enhance safe and reliable power delivery. The transmission lines in El Dorado County deliver power from the SMUD’s Upper American River Project (UARP), the huge system of hydroelectric power plants in the Sierra. The UARP’s nearly 700 megawatts of clean power can provide about 20 percent of SMUD’s power in a normal water year, which can be crucial especially in summer months when market power is more expensive.
Reliability is a core value of SMUD, a policy set by the SMUD Board of Directors who is elected by SMUD customers. To fulfill that policy, SMUD continues to bolster the infrastructure that comprises SMUD’s grid. For more information about SMUD, visit SMUD.org.