Clocks May Drift While US Power Grid Adapts To Increased Use Of Renewable Energy
"Alarm Clock 2" Image credit:Flickr, Alan Cleaver
To adapt the nation's power grid to increased use of renewable power, it is proposed that procedures for meeting AC power transmission frequency standards be altered somewhat (see below for explanation of existing practice). Associated Press reports that the North American Electric Reliability Corp. wants to see a revised scheme tested for a year, during which clocks directly running on AC power may slow or speed up a few minutes per year (extent and direction of change depends on which regional grid you live in). Nothing to head into a YTK-style panic over, mind you: devices with AC-to-DC transformers and/or running on batteries will not be affected; but some alarms, traffic lights, kitchen appliances, and so on will be.Power politics.
AC-powered clocks slowly drift off standard time already; but, I think I can see where this proposed small, additional change might take us.
Once Rush Limbaugh reports that alarm clocks will be affected by socialist-favored renewable power, Think Tank Experts will let Congress know that business productivity could be slowed as employees show up late for work, or early for meetings.
House Republican leaders and Fox News reporters will demand Federal incentives for solar or wind power be stopped immediately. Senator Mitch McConnell will hold a press conference, flanked by his stalwarts and lit only by antique incandescent bulbs, declaring that the debt ceiling can not be raised until real Americans get their coal-fired electricity back.
Wikipedia provides a succinct explanation of power transmission frequency maintenance practices in the USA.
Regulation of power system frequency for timekeeping accuracy was not commonplace until after 1926 and the invention of the electric clock driven by a synchronous motor. Network operators will regulate the daily average frequency so that clocks stay within a few seconds of correct time. In practice the nominal frequency is raised or lowered by a specific percentage to maintain synchronization. Over the course of a day, the average frequency is maintained at the nominal value within a few hundred parts per million. In the synchronous grid of Continental Europe, the deviation between network phase time and UTC (based on International Atomic Time) is calculated at 08:00 each day in a control center in Switzerland, and the target frequency is then adjusted by up to ±0.01 Hz (±0.02%) from 50 Hz as needed, to ensure a long-term frequency average of exactly 24×3600×50 cycles per day is maintained. In North America, whenever the error exceeds 10 seconds for the east, 3 seconds for Texas, or 2 seconds for the west, a correction of ±0.02 Hz (0.033%) is applied. Time error corrections start and end either on the hour or on the half hour. Real-time frequency meters for power generation in the United Kingdom are available online - an official National Grid one, and an unofficial one maintained by Dynamic Demand.  Smaller power systems may not maintain frequency with the same degree of accuracy.