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Peak Heat, Surf Expected In San Diego County

 Beachgoers at the La Jolla Cove bask in the sun, July 22, 2018.
KPBS Staff
Beachgoers at the La Jolla Cove bask in the sun, July 22, 2018.
Peak Heat, Surf Expected In San Diego County
An update on Flex Alerts in California GUEST: Steven Greenlee, senior public information officer, California Independent System Operator

Are a heat wave is now mixed with humidity which may keep temperatures down slightly but officials are still concerned about the demand on the state's electricity grid. A Flex Alert that calls for electricity conservation is in effect from five to nine. Tonight one irony we're facing this hot summer is that as use of alternative energy sources like solar increases the actual strain on the traditional energy grid increases during high usage. Earlier I spoke with Stephen Green senior public information officer with the California Independent System Operator. Steven welcome to the program and thank you very much for having me. Remind us if you would what a Flex Alert is and how people are supposed to respond to it. Yes a flood Szilard is a voluntary call for conservation. We put that out whenever we see that there is going to be stress on the grid and during heatwaves like we are now experiencing throughout California we are seeing where demand is being driven up by high air conditioning loads. And so we just go out and we asked the Californians to just ease up on using electricity in that way it helps us meet our afternoon peaks and what happens if a Flex Alert doesn't work if people don't do that well. So it is voluntary and we don't have a way to go out and count and see what 30 million people are doing. But what we do see is that they have responded in the past and we would expect that they are responding today as well. So we have seen in the past that we're getting between 250 to 500 megawatts of peak load Shavian and that's about the size of two normal sized power plants. About a half a million homes. That's what it would power. So they are responding. But there is. It's all voluntary so there is there's no penalty if they don't with all the options for power. Now we have solar wind. There's natural gas. Why is the electric grid. Why is the electric grid still straining to meet demand during a heat wave. Well because grids are not finite it's not something like out of Star Trek where you have infinite amounts of power that we can we can generate and and ship around. We're now coming up to the upper limits of the system in which we have been building for the past many decades. And so just like like with water or gasoline there's only so much that the system can handle. And so during extreme heat waves were seen many thousands and thousands of megawatts that are being used in order to power air conditioning plus everything else that we do. So we're just saying that for what we are seen at least for the next couple of days is that we are looking at reaching the upper ends of our system capability. So it's not so much the energy that you have it's the capacity to deliver it. Is that right. Well that's part of it. So we have two elements involved. One is the generating plants. And so we have generating plants now online that should hopefully give us a couple of thousand megawatts of wiggle room. But if something should happen to one of those generating plants and it goes off line then we would have a concern. The other is transmission capacity in order to deliver it. And the same thing goes with that just like a waterpipe transmission lines can only carry so much electrons. And so if demand is trying to pull more power to those lines somewhat they're capable of. Well the electricity doesn't doesn't get delivered. So it is a combination of both. Now the Flex Alert is focused on a 5 p.m. to 9 p.m. timeframe. Didn't the peak usage times across the state used to be a little bit earlier. Yes it did. Used to be from 4:00 to 6:00 p.m.. But what we've been seeing since. California has instituted its renewables portfolio standard and it's policies to to reinvent the grid with cleaner and greener resources especially with solar resources. We've seen that that's moving our peak times up later in the day and but also at the same time as the sun is still lingering but not totally gone. Demand is still rising and so we have to replace the diminishing solar resources with resources while demand is rising. And that's quite a challenge right apparently because solar power fades out during the evening. It's forcing the traditional power sources to actually ramp up very quickly. Tell us about that. Yes it does have to ramp up very quickly we're seeing in some cases a ramp of three hours in the late afternoon early evening of 15000 megawatts and so that is one of the challenges that we have seen happen on the grid with the advent of adding more solar to the grid. Luckily the California Independent System Operator California so we've been able to pioneer techniques and processes in order to better manage that and we're still working on that. Have we come close to any peak usage records so far this summer. Not yet. The summer so our all time record peak is fifty thousand two hundred and seventy megawatts which was set in a very hot July 2006. Last year we had our all our seasonal peak into 2017 of fifty thousand one hundred and sixteen megawatts. So far we've only hit about 49000 this year. So we still have a little bit of room before we start looking out any kind of records. Okay so once again a Flex Alert is in effect from five to nine tonight that calls for reduced electricity usage and I've been speaking with Stephen Greenlees senior public information officer with the California Independent System Operator. Stephen thanks. Thank you very much for having us.

A record-setting heat wave is expected to reach its peak Wednesday along with dangerous surf conditions in San Diego County, before temperatures cool slightly for the weekend.

The extreme heat, which began Monday, could push temperatures into the high-80s along the coast, 102 in the inland valleys, to 108 degrees in the mountains and into the low-120s in the desert, according to the National Weather Service.

Ramona is forecast to see the mercury rise to 108 degrees the day after it tied its record high temperature for a July 24 with 103 degrees Tuesday.


A high-temperature record was set Tuesday in Borrego with 118 degrees and it is forecast to eclipse another record temperature Wednesday with 119 degrees.

Due to the severity of the heat wave in the local forecast for much of the week, an NWS excessive-heat warning will remain in effect in the county through 8 p.m. Thursday.

High temperatures Wednesday are expected to set records in San Diego, Chula Vista, Escondido, El Cajon, Ramona, Alpine and Borrego, according to the NWS.

The NWS issued a High Surf Advisory that lasts until 9 p.m. Wednesday.

Strong rip currents and high surf levels of 5-7 feet could cause dangerous swimming conditions for inexperienced swimmers, the NWS said.


Authorities urge the public to avoid potential health hazards by drinking plenty of water or other non-alcoholic fluids, seeking out shady and/or air-conditioned environments and checking up on relatives and neighbors —particularly the elderly or home-bound people — to ensure that they are handling the heat all right.

In addition, young children and pets should never be left unattended in vehicles during hot weather, when car interiors can reach lethal temperatures in a matter of minutes, officials warn.

A list of local public "cool zones" can be found at

The heat wave is expected to break after Thursday, with high temperatures returning to the mid-90s in most areas of the county for the weekend.