[Noisebridge-discuss] De-syncing the electric grid

girlgeek girlgeek at wt.net
Sun Jun 26 07:21:11 UTC 2011


I wonder how many medical &/or hospital &/or life support devices are 
dependent on current based time?
-Claudia

On 6/24/2011 7:27 PM, walter park wrote:
>
> 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 <http://time.gov/>_or call 202-762-1401 
> <tel:202-762-1401>
>
>
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