It’s one thing to keep hackers out of your power supply. But how can utilities do battle against uncontrollable forces?
Bad weather — which Clark County has seen plenty of this fall — and natural disasters such as earthquakes and wildfires are the most common culprits in causing outages.
Clark Public Utilities uses a variety of tools to combat the wind, rain and snow, such as “tree wire,” vegetation management, underground cable treatment and an employee who watches hot spots and tries to prevent outages.
While that’s a start, it won’t stop every outage.
“Certainly there are always more things we could do that would further improve reliability, such as undergrounding existing power lines, installing more “smart” grid/meter technology and replacing aging equipment on an even more aggressive schedule,” said utility spokeswoman Erica Erland. “That said, maintenance of a system always requires a balance between costs, capacity of the workforce and the impact on the public in terms of disruptions caused by upgrades.”
In 2014, the average Clark Public Utilities customer experienced about 3.5 hours of outages including all major weather events, and 39 minutes of outages without major events, according to data from the U.S. Energy Information Administration.
“The utility has very ambitious reliability goals that are set annually,” Erland said. “We consistently meet these goals and have very high reliability compared to utilities of similar size.”
That comes back to “hardening” the utility’s systems, or taking steps to improve infrastructure and outage response.
Erland said that being a publicly owned utility, as opposed to private or investor-owned, can make reliability a bigger priority.
The same can be said of the federal Bonneville Power Administration, which owns 75 percent of the high-voltage transmission lines in the Northwest.
“With that large of a grid infrastructure, there are many areas where lines are redundant — meaning two or more separate transmission lines feed power to that area,” said BPA spokesman Kevin Wingert. “Where possible, we’ve built in alternate routes along differing geographical footprints that help to mitigate the impact from an incident.”
The BPA, which provides about 60 percent of Clark Public Utilities’ power, also has worked since the late 1980s to prepare for a high-magnitude earthquake such as the Cascadia Subduction Zone quake, which has a 10 percent chance of striking in the next 50 years. Seismic improvements include updated design standards and retrofitted transformers and substations, Wingert said.
For all disasters, he said, the agency also maintains backup centers at far-off sites “to mitigate the impacts of a localized incident.”
No electric system is immune to the forces of the Earth, though there are ways to get close.
“BPA always balances the value of new structural improvements, technology and resources with our goal of keeping upward pressure on rates low,” Wingert said.
A BPA rate increase this fall was absorbed by Clark Public Utilities, which has not passed a rate increase since 2011, Erland said.
Most of the utility’s budget covers the cost of power, whereas operations and maintenance is just 14 percent.
