Beating the Heat Wave: A South Bay Homeowner's Guide to Smarter AC Use

If it feels like the AC has been running nonstop this week, it's not your imagination. Southern California is in the middle of a serious heat wave — the National Weather Service has Extreme Heat Warnings up for inland LA County, where temperatures have climbed past 106–110°F. Here in Manhattan Beach and the rest of the coastal South Bay, the marine layer is doing its job and keeping us in the 90s instead of the low 100s — but "milder" during a heat wave like this one still means your AC is working overtime, and your bill will show it.

Here's how to get through it without either roasting or overpaying.

Why coastal doesn't mean cool this week

The South Bay's biggest advantage in a heat wave is geography — being a few miles from the water usually keeps us 10-15 degrees cooler than the Valley or Inland Empire. But a heat wave this strong still pushes coastal temps into the 90s, and humidity from the marine layer can make it feel stickier than the number on the thermometer suggests. That's enough to spike AC demand across the whole grid at the same time — coastal and inland alike — which is exactly when electricity gets both scarcer and more expensive.

The window that matters most: 4 to 9 p.m.

Almost every SCE time-of-use plan prices electricity highest from 4 to 9 p.m. — the same hours the statewide grid is under the most strain from everyone's AC running at once. During major heat events, the California ISO (the agency that manages the state's power grid) will sometimes call a "Flex Alert," asking everyone to voluntarily cut back during that window to avoid blackouts. Worth checking flexalert.org the day of, since alerts are usually announced same-day.

Whether or not one's been called this week, the moves are the same:

Pre-cool in the late morning. Run your AC a little harder between roughly 10 a.m. and 2 p.m., while your solar panels are producing the most and the grid is least stressed. Get the house a couple degrees cooler than you need, then ease off.

Ease up from 4 to 9 p.m. Raise the thermostat 2-4 degrees during this window if you can stand it — you already pre-cooled, so the house has a head start. Ceiling fans make a couple extra degrees feel like nothing.

Let the battery take the evening shift. If you have battery storage, this is exactly the scenario it's built for — discharge through the 4-9 p.m. peak instead of pulling from the grid, then let it recharge overnight or from solar the next morning.

Charge your EV outside the window. Midday off solar, or after 9 p.m. once rates and grid demand both drop — either beats plugging in right when you get home from work.

Use the marine layer. Once evening fog rolls in, coastal South Bay homes can often shut the AC off entirely and open windows — something inland neighbors don't get to do until much later, if at all.

A couple of practical notes

Close blinds or shades on west-facing windows in the afternoon — it's a free few degrees. And if you haven't changed your AC filter recently, a heat wave is exactly when a dirty one costs you the most in efficiency. If you're checking in on elderly neighbors or relatives without AC, LA County's cooling center map (ready.lacounty.gov/heat) is worth having handy this week.

Our take

Heat waves like this one are a pretty good real-world stress test for a solar and battery system — if your battery's been quietly covering your evening peak all week without you noticing, that's the system working exactly as designed. If you've been watching your AC run and wondering whether your setup (or lack of one) is really doing the job during weeks like this, that's a conversation we're always happy to have.