July 9, 2002 — Conservation could play a key role in helping the California Independent System Operator (California ISO) avoid a Stage One Electrical Emergency recently.

While the ISO is not predicting blackouts, operators in the ISO Control Room will have to find power recently to make up the loss of approximately 2,200 megawatts of power generation that fell off-line due to mechanical problems in the past 24 hours. Compounding the problem is the regional nature of the heat wave affecting California this week.

High temperatures are blanketing most of the western United States and neighboring states do not have as much imported power to share with California.

The peak demand for electricity is expected to come at around 4:00 p.m. recently and crest at some 40,402 megawatts (does not include the peak demand for the Sacramento Municipal Utility District, which is estimated to be 2,548 megawatts recently).

Because both northern and southern California will be hot recently, the coincidental high peak demand could produce the biggest electrical loads the state has seen so far this year.

Lower import levels, power plant outages and the residual heat build-up that comes from a lengthy heat wave are all prompting the California ISO to call on consumers to curtail their use of electricity through Thursday, especially during the peak hours of between 4:00 and 6:00 p.m. Conservation tips can be found at www.caiso.com.

“California is almost entirely dependent on power plants internal to the control area recently,” said Director of Grid Operations Jim McIntosh. “With some of those California plants tripping off-line overnight, we will also be more dependent on consumers practicing conservation. It is important that Californians know they do make a difference when they avoid using heavy electrical appliances during the peak period.”

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 a 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.