[Noisebridge-discuss] De-syncing the electric grid

walter park waltsfo at gmail.com
Sat Jun 25 02:27:09 UTC 2011


AP story:

Experiment with power grid may throw off your electric clock

By SETH BORENSTEIN
AP Science Writer

06-24-2011 15:57

WASHINGTON (AP) _ Our power supply has been so precise that we've set our
clocks by it. But time may be running out on that idea.

A yearlong experiment with the electric grid may make plug-in clocks and
devices like coffeemakers with programmable timers run up to 20 minutes
fast.

The group that oversees the U.S. power grid is proposing a change that has
the potential to disrupt electric clocks in schools, hospitals and other
institutions, according to a company presentation obtained by The Associated
Press. It may also mess with the timing of traffic lights, security systems,
sprinklers and some personal computer software and hardware.

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

The experiment would allow more frequency variation than it does now without
corrections. Officials say they want to try this to make the power supply
more reliable, save money and reduce what may be needless efforts. The test
is tentatively set to start in mid-July, but that could change.

Tweaking the power grid's frequency is expensive and takes a lot of effort,
said Joe McClelland, head of electric reliability for the Federal Energy
Regulatory Commission.

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

They will and they should, timekeepers say.

"A lot of people are going to have things break and they're not going to
know why," said Demetrios Matsakis, head of the time service department at
the U.S. Naval Observatory, one of two official timekeeping agencies in the
federal government.

The changes, however, are out of the hands of timekeepers and in control of
officials who supply the electrical power.

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

But wall clocks and those on ovens and coffeemakers _ anything that flashes
"12:00" when it loses power _ may be just a bit off every second, and that
error can grow with time.

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

This will be an interesting experiment to see how dependent our timekeeping
is on the power grid, Matsakis said.

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

Some parts of the grid, like in the East, tend to run faster than others.
Errors add up. If the grid averages just over 60 cycles a second, clocks
that rely on the grid will gain 14 seconds per day, according to the
company's presentation.

Spokeswoman Kimberly Mielcarek said the company is still discussing the test
and gauging reactions to its proposal, and may delay the experiment a bit.

Mielcarek said in an email that the change is about making the grid more
reliable and that correcting the frequency for time deviations can cause
other unnecessary problems for the grid. She wrote that any problems from
the test are only possibilities.

In the future, more use of renewable energy from the sun and wind will mean
more variations in frequency on the grid, McClelland said. Solar and wind
power can drop off the grid with momentary changes in weather. Correcting
those deviations is expensive and requires instant back-up power to be
always at the ready, he said.

The test makes sense and should not cause too much of a hassle for people,
said Jay Apt, a business professor and director of the Electricity Industry
Center at Carnegie Mellon University.

But Tim O'Brian, who heads the time and frequency division at the National
Institute of Standards and Technology,
expects widespread effects.

He said there are alternatives if people have problems from the test: The
federal government provides the official time by telephone and on the
Internet.

Official U.S. government time:
*http://time.gov* or call 202-762-1401
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