Changes made to power grid might disrupt clocks

WASHINGTON - A yearlong experiment with the nation's electricgrid could mess up traffic lights, security systems and somecomputers - and make plug-in clocks and appliances like programmablecoffeemakers run up to 20 minutes fast.

"A lot of people are going to have things break and they're notgoing to know why," said Demetrios Matsakis, head of the timeservice department at the U.S. Naval Observatory, one of twoofficial timekeeping agencies in the federal government.

Since 1930, electric clocks have kept time based on the rate ofthe electrical current that powers them. If the current slips offits usual rate, clocks run a little fast or slow. Power companiesnow take steps to correct it and keep the frequency of the current -and the time - as precise as possible.

The group that oversees the U.S. power grid is proposing anexperiment that would allow more frequency variation than it doesnow without corrections, according to a company presentationobtained by The Associated Press.

Officials said they want to try this to make the power supplymore reliable, save money and reduce what might be needless efforts.The test is tentatively set to start in mid-July, but that couldchange.

Tweaking the grid's frequency is costly and takes a lot ofeffort, said Joe McClelland, head of electric reliability at theFederal Energy Regulatory Commission.

"Is anyone using the grid to keep track of time?" McClellandsaid. "Let's see if anyone complains if we eliminate it."

No one is quite sure what will be affected. This won't change theclocks in cellphones, GPS or even on computers, and it won't haveanything to do with official U.S. time or Internet time.

But wall clocks and those on ovens and coffeemakers - anythingthat flashes "12:00" when it loses power - might be just a bit offevery second, and that error can grow with time.

It's not easy figuring what will run fast and what won't. Forexample, VCRs or DVRs that get their time from cable systems or theInternet probably won't be affected, but those with clocks tied tothe electric current will be off a bit, Matsakis said.

The North American Electric Reliability Corp. runs the nation'sinterlocking web of transmission lines and power plants. A June 14company presentation spelled out the potential effects of thechange: East Coast clocks might run as much as 20 minutes fast overa year, but West Coast clocks are only likely to be off by 8minutes. In Texas, it's only an expected speedup of 2 minutes.