California's Plan to Reduce Consumption on August 21

Looking ahead to the "Great Solar Eclipse" that will occur this summer on August 21, the California Public Utilities Commission has challenged consumers to lower electricity use statewide by at least 3,500 megawatts (MW) that day. The commission targeted the hours of 9:00 a.m. to 11:00 a.m. for the reduction in consumption, explaining that a partial solar eclipse is predicted to travel across California from about 9:02 a.m. until approximately 11:54 a.m., with the sun being obscured from 76% in Northern California to 62% in Southern California.

According to the commission, the accompanying decrease in solar radiation will directly affect the output of both large-scale photovoltaic (PV) power facilities and individual rooftop solar panels.

In light of the fact that nearly 10,000 MW of commercially operable, grid-connected solar PV is currently operated by California's investor-owned utilities, with more to be completed soon, the commission said that initial projections indicate that at the eclipse peak, commercial solar production for the investor-owned utilities may fall from an estimated 8,754 MW to 3,143 MW before returning to 9,046 MW. The commission related that the normal morning solar ramp that day will beinterrupted with a down ramp beginning at 9:02 a.m., followed by a greatly accentuated up ramp going from 10:22 a.m. until noon. The commission therefore urged all citizens to refrain from using appliances during that time and to unplug from the grid. To that end, it reminded consumers that 23% of the electricity used in powering home electronics is actually consumed while the products are turned off. It thus recommended that consumers turn off power strips or unplug electronics when not in use, not only during the eclipse, but on an ongoing basis.

The commission also suggested that consumers consider only using devices and equipment that draw large amounts of power, such as dishwashers, air conditioners, and washing machines, at night. It added that significant reductions in power usage likewise can be accomplished simply by upgrading to light-emitting diode (LED) bulbs.