Energy emergency alert raised for second day, residents urged to curb electricity use

The California Independent System Operator on Wednesday afternoon issued an Energy Emergency Alert 2, in effect from 4 to 9 p.m.

The alert means the state's power grid manager is requesting emergency supplies from all resources to meet what is expected to be a heightened demand for electricity. Cal ISO is calling on people to step up their conservation efforts further to avoid the possibility of rolling blackouts.

Earlier Wednesday, the grid operator issued an Energy Emergency Alert 1, in effect from 4 to 9 p.m.

Residents are already being urged to cut their power use during those hours due to a previously declared Flex Alert, but Cal ISO is again calling on people to step up their conservation efforts further to avoid rolling blackouts.

With electricity demand reaching record levels due to a drawn-out heat wave, Southern California and the whole state avoided rolling power blackouts as the manager of the power grid called for maximum conservation efforts by residents.

On Tuesday morning, Cal ISO declared an Energy Emergency Alert 1 for the same hours, warning utilities that all electricity resources are expected to be fully committed and some shortages are possible. By early afternoon, Cal ISO moved to Energy Emergency Alert 2, requesting all available emergency supplies to be made available to meet the demand. And just before 6 p.m., the state moved into Energy Emergency Alert 3, calling for maximum conservation efforts while warning that blackouts could be imminent absent reduced demand.

To drive home the demand, alerts were sent to cell phones across the state urging people to "conserve energy now to protect public health and safety," and warning that "power interruptions may occur unless you take action."

"As the state faces the hottest day in this prolonged, record-breaking heat wave, grid conditions are expected to worsen," according to the power-grid manager. "If needed, ISO could order utilities to begin rotating power outages to maintain stability of the electric grid. If that occurs, consumers should expect communications — either phone, text or email — from their utilities notifying them of outage areas and likely durations."

If energy reserves are exhausted, the ISO would instruct utilities in its service area to manage rolling blackouts. Utilities make the determination of how best to spread and rotate the outages across their service territory, with the goal of keeping them as short as possible.

"Outages are a significant inconvenience to those affected, but it's preferable to manage emergencies in a controlled manner rather than let it cause a wider spread, longer lasting disruption," according to Cal ISO. "Power interruptions are kept as brief as possible and utilities rotate them through their customer base so that no one area has prolonged outages. Utilities make the determination of how best to spread and rotate the outages across their customer base, with the goal of limiting their duration as much as possible."

Cal ISO officials said calls for conservation have paid off so far during the heat wave, with no power interruptions occurring.

By late Tuesday afternoon, electricity demand reached 51,426 megawatts, breaking the all-time record of 50,270 MW set in 2006, according to Cal ISO. Wednesday's load is forecast at 49,868 MW.

Consumer and commercial demand response, including Flex Alerts, has been helping to extend tight resources over the past week, with a load reduction of around 1,000 MW for each of the past several days.

During the Flex Alerts, residents are urged to take the following power-saving steps:

— setting thermostats to 78 degrees or higher;

— avoiding use of major appliances;

— turning off unnecessary lights; and

— avoid charging electric vehicles.

Residents were also advised to pre-cool their homes as much as possible and close blinds and drapes to keep interiors cool.

Southern California has seen temperatures soar above 100 degrees every day since last Wednesday, with little relief in sight until at least Friday.

Overnight lows are not offering much relief either, staying in the 70s and even in the low 80s in some of the hotter areas.

In San Diego, a minimum temperature of 73 on Tuesday night tied a record set in 1995.

High temperatures continued Monday across much of San Diego County. The high reached 86 in downtown San Diego, 90 in Chula Vista and a scorching 109 in Borrego Springs.

The National Weather Service extended the excessive heat warning that has been in effect all weekend, which is now set to expire at 8 p.m. Friday.

"Strong high pressure to the north will continue the heat wave through Thursday for inland areas, with the heat continuing through Friday for the coast and valleys," according to the NWS. "For next weekend, a weakening tropical system will bring increasing moisture, breezy conditions, and a chance of more widespread showers and isolated thunderstorms. Showers and higher humidity will linger through early next week."

Health officials advise residents to stay indoors with air conditioning whenever possible, drink plenty of fluids and avoid hiking or other strenuous activity in extreme heat.

Children and pets should never be left in unattended vehicles for even one minute.