By Jonathan Marshall
In the bucolic environs of Rio Vista, the largest small town in Eastern Solano County, life is grand unless the lights go out. Unfortunately, the long rural electrical circuits that serve that community of 7,300 are subject to being knocked out by extreme weather, unwary tractor drivers hitting power poles and birds that unwisely straddle the charged wires.
Few of the residents probably know it, but they are now early beneficiaries of the smart grid—21st century technology that is helping the electrical system become more reliable, even to the point of healing itself automatically when damage occurs.
PG&E recently piloted a smart grid technology called Fault Location, Isolation, and Service Restoration (FLISR) on 25 miles of circuits served by the Grand Island substation in the Delta. Besides Rio Vista, they deliver power to Isleton and Clarksburg along the Sacramento River, as well as local farms and ranches.
Using a device called an intelligent switch, FLISR can in theory detect a short-circuit, block power flows to the affected area, communicate with other nearby switches, and then reroute power around the problem to keep as many customers energized as possible—all within five minutes.
But does it work in practice? There’s no longer any doubt.
On the morning of September 12, a downed overhead line took out one of PG&E’s two circuits to Rio Vista. The FLISR equipment sized up the problem, quarantined the bad section and restored service to 1,774 of 2,294 customers in under 2 ½ minutes.
Based on typical repair times, that quick response slashed the number of affected customers by 77 percent and the number of minutes they were out of power by two-thirds.
PG&E installed the FLISR equipment as part of its Cornerstone Improvement Program, authorized by the California Public Utilities Commission (CPUC) last year with a budget through 2013 of about $360 million. About half of the money will be used to help automate more than 400 of PG&E’s 3,200 electric distribution circuits.
The utility has been carefully testing available technology for many months to make sure its investment pays off for years to come.
This will be a big deal to many customers. An hour of downtime can cost businesses tens, even hundreds of thousands of dollars. (That’s one reason some invest a lot of money in backup generators.) But even if you’re working from home, an hour lost can blow your deadline, costing you money and aggravation.
If FLISR upgrades work as well in more populated areas as they did in the Delta, these customer benefits will really add up. The CPUC has said it will take a fresh look at the technology in 2014 with an eye to authorizing more upgrades if they prove cost-effective.