Generally, the utilities "cycle" the air conditioners. Fifteen minutes on, 15 minutes off.
And the cycling applies only to the compressors. The blower that circulates your household's air keeps running, if your thermostat tells it to, so your house doesn't become a fetid swamp.
Peco has probably the best deal — $30 a month for June through September, or $120 total.
Once you enroll, they come out and attach a device to your central air conditioner that will let them take control.
PPL offers $32 for those who enroll. In New Jersey, PSE&G and Atlantic City Electric both offer a one-time $50 credit and a programmable thermostat.
Even if you buy electricity through a competitor, one of these is bound to be your power distributor, so you're still eligible.
The four companies combined have nearly a quarter of a million willing sweatees signed up.
Customers also will save because they will presumably use less electricity overall.
Further, the utilities say customers won't really suffer higher home temperatures.
But naturally, experiences vary. If you live on a treeless lot with a dark roof, let the sun stream through the windows, and keep the thermostat set at 69 degrees, this likely will not work for you.
But if you have shade and good insulation, you draw the blinds, and you opt for a more sensible temperature, you're a good candidate for the program.
When Peco did a test run with employees, the most they saw was a temperature increase of 2 to 3 degrees, said spokeswoman Cathy Engel Menendez.
The utilities can interrupt the air conditioning whenever they think it's necessary — there's no regulatory threshold. How often they do so in any given summer depends on the weather. Last year, Peco had just two cycling events. But they anticipate a norm of more like 13 to 20 per summer.
Usually it comes during the week, during the afternoon, when most people aren't home anyway.
I had no idea this was an emotional issue, but when I brought it up at a meeting of colleagues recently, the group erupted. "I'm not giving Peco control of my air conditioner!" one almost shouted. Shades of Big Brother?
But another chimed in, "It makes sense. Why wouldn't you do it?"
Yet another guy I talked to was convinced his home would heat up to sweltering levels, and he'd spend just as much money, and half the evening, cooling it back down again. "I don't trust it," he said.
Pennsylvania utilities do this as part of their compliance with a state law, Act 129, part of which requires them to reduce peak demand 4.5 percent by May 31, 2013. Christina Simeone, director of the PennFuture energy center, said the program had been successful. An extension of the program is being developed by the state, and environmental groups hope for significant additional energy efficiency goals.
But there's more to this than mere regulation.
The utilities say the programs will help all their customers in the long run by keeping overall costs down.
On the utility end, it works like this: Say you have a block of 100 houses. Say most of the air conditioners are on only a half hour out of every hour anyway. There's no guarantee all 100 units won't be whirring at the same time.
But by cycling them, the utility can guarantee that only 50 units will be operating at one time. This shaves off the expensive peaks in power demand. Although residential customers pay one rate on their bills, utilities have to pay the going rate, which is higher during periods of peak demand.
I wondered if this wasn't what the American Council for an Energy-Efficient Economy (ACEEE) was talking about last week, when it released a report on "intelligent efficiency."
Intelligent efficiency is the next step beyond having highly efficient individual devices, such as refrigerators or autos that get good mileage. Intelligent efficiency is more about how the devices are used. A "smart" refrigerator, for example, would communicate with the grid to get a real-time energy price and then adjust its operations accordingly.
ACEEE's associate director for research, R. Neal Elliott, said that in the case of air-conditioner cycling, intelligent efficiency would let you override it by flipping a switch. So if you're having a big dinner the day the utility decides to call an event, you can tell it to scram.
The psychology of this turns out to be very odd. Giving people more control results in customer satisfaction's going way up. But in the end, most people never use that control.
Or, if there's an energy crisis of some sort, the utility can communicate this to each customer, and people can voluntarily make adjustments, receiving compensation for being good citizens.
In short, intelligent efficiency is where you get interaction, "not just a dumb switch," Elliott said. I'm looking forward to it.
Meanwhile, he has no qualms about programs like air-conditioner cycling. "They've saved utilities a lot of money," he said, "and they've saved consumers a lot of money."
"GreenSpace" appears every other week, alternating with Art Carey's "Well Being" column. Contact staff writer Sandy Bauers at 215-854-5147, email@example.com or @sbauers on Twitter. Visit her blog at www.philly.com/greenspace.
For More Information or to Sign Up for a Program:
Peco's Smart A/C Saver program: visit www.peco.com/SmartIdeas or call 1-888-573-2672.
PPL's E-Power Peak Saver program: visit www.epowerpeaksaver.com or call 1-866-748-2333.
PSE&G's Cool Customer program: visit www.pseg.com/coolcustomer or call 1-888-504-4028.
Atlantic City Electric's Energy Wise program: visit www.atlanticcityelectric.com/rewards or call 1-866-355-4229.