San Diego Plane Crash Stresses Grid During First Heat Wave

Business Wire, July 3, 2007

Conservation Critical During Peak Demand Hours This Afternoon!

FOLSOM, Calif. -- The California ISO reports that a small plane taking off this morning from McClellan-Palomar airport in the San Diego area clipped two high-voltage transmission lines before crashing. In addition, approximately 1,900 megawatts of generation in Southern California tripped offline overnight due to issues apparently unrelated to the plane crash. However, the loss of transmission capacity and generation, coupled with higher demand today due to increasing temperatures, could result in reduced energy reserves this afternoon not just in San Diego but potentially statewide. The California Independent System Operator Corporation (California ISO) is urging all Californians to conserve power during the peak hours this afternoon, roughly 2:00 to 6:00 p.m.

Simply turning of unneeded lights and appliances, waiting to run major appliances in off-peak hours, and raising your thermostat from 72 to 78 can make a difference. People with a disability, seniors, or anyone who has difficulty regulating body temperature, please leave your air conditioner set at 72 degrees and take any other necessary precautions to safeguard your health. For more conservation and energy efficiency tips, please visit www.fypower.org.

Early indications are that at least some of the power plants that tripped off last night will be back in time for the peak demand this afternoon, however, these are old and complex machines, and there are no guarantees. Currently there is no estimated time of return for the transmission capacity. Reducing demand through voluntary conservation is the prudent thing to do, especially with a significant heat wave due in California this week.

With temperatures over one hundred degrees expected throughout the region by Wednesday, July 4, air conditioning use is going to drive higher demand for electricity. The California ISO is predicting a peak demand of approximately 43,500 megawatts today, 42,600 megawatts tomorrow and nearing 47,000 megawatts on Thursday, July 5. The all time record peak demand for the California ISO is 50,270 megawatts set on July 24 last year.

The California ISO is a not-for-profit public benefit corporation charged with managing the flow of electricity along California's open-market wholesale power grid. The mission of the California ISO is to safeguard the reliable delivery of electricity, and ensure equal access to 25,000 circuit miles of "electron highway." As the impartial operator of the wholesale power grid in the state, the California ISO conducts a small portion of the bulk power markets. These markets are used to allocate space on the transmission lines, maintain operating reserves and match supply with demand in real time.