PSE’s two newest solar-powered systems in Edmonds, Wash., use the sun to produce electric current along more than six miles of buried natural gas steel pipe to block corrosion caused by the electrochemical reaction between the metal pipe and the surrounding soil. The anticorrosion technique, called cathodic protection, uses a small amount of electric current to charge the pipe’s surface and direct the rust to an anode. This in effect “fools” the pipe, targeting the corrosion elsewhere, increasing the longevity of the pipe and, long-term, decreasing the potential for natural gas leaks.

In total, the utility’s nearly 85 solar-powered cathodic protection systems installed in six counties protect more than 250 miles of buried natural gas steel pipe.

Without needing to be positioned near a source of socket-ready power, PSE’s solar units can be installed nearly anywhere. “While good for the environment, these solar installations give us the latitude to operate our natural gas protection systems in remote areas where other sources of power may be difficult to install or operate,” said Sue McLain, PSE senior vice president of Operations. “It’s fitting for PSE, which operates the Pacific Northwest’s largest solar power-generating facility at our Wild Horse Wind and Solar Facility near Ellensburg to have also helped pioneer this technique to take advantage of solar energy to help protect our natural gas system.”

With approximately a quarter of PSE’s 300 cathodic protection systems operating on solar power, PSE is the only Washington state utility using solar technology to protect its natural gas system, and one of the largest users in the U.S. PSE installed its first solar powered cathodic protection system in 1984.