Entergy Arkansas is trying to enlist its residential customers in a program that would automatically let temperatures go up to keep the utility's costs down.
Residential customers taking part in Entergy's Summer Advantage Program agree to the installation of a device called a Direct Cycling Unit on their central air conditioning units that will shut down compressors during periods of peak electricity use. Those who sign up before July 31 will get rebates either $50 or $80, depending on the reduction in A/C.
The utility announced the program to its 700,000 customers last month.
Entergy is upfront about the fact that, while the compressor is off, indoor temperatures will rise. And with a relentless chain of 100-plus highs in our immediate future, some Central Arkansans are wary about signing up. "There's many things in my life that I don't have control over ... therefore, I like to keep control over what I can control. And I like being in control of my own thermostat," Peggy Young Seamon wrote on the Arkansas Times Facebook page.
But other customers, especially those who keep their thermostats high anyhow, seemed to welcome the rebate. About 1,895 Entergy Arkansas customers have volunteered for Summer Advantage so far, and 756 DCUs have been installed.
The compressor in an air conditioning unit turns itself on and off multiple times throughout the day to protect its motor from overheating. The DCU, which is about the size of a child's shoebox, connects to the appliance and measures how many minutes the compressor cycles on each hour. During the hottest part of the day, generally mid-morning to mid-afternoon, compressors' switch on en masse to keep interior temperatures stable. In times of peak usage, the DCU shuts off the compressor either 50 to 75 percent longer than it did during the previous hour. If a compressor blew cold air for 30 minutes in the previous hour, and the customer is on a 50 percent cycle, the compressor would only blow cold air for 15 minutes of every hour during peak usage. According to Entergy, "peak usage" can last up to four hours. Summer Advantage will primarily cycle down compressors on weekdays before 7 p.m. The DCUs, which are remotely controlled by the utility, would only be activated on weekends and holidays in the case of an unforeseen crisis. "When commercial businesses aren't in operation, it offsets demand considerably. We're still monitoring that demand level every day, especially during the summer when we're in triple digit temps, but it's usually lighter on weekends and holidays," said Julie Munsell, an Entergy spokesperson. Customers who sign up for the program at 50 percent cycling will receive $50, paid out as $25 upon installation and $25 in December. Those who select 75 percent cycling will receive a $40 upon installation and $40 in December.
Munsell said most customers won't notice a change on their bills, but if there is a change, it should be for the better. "When the compressor cycles off, the fan continues to run, which helps mitigate the change in temperature and keep the house as cool as possible. This is so your unit doesn't have to work harder when it cycles back on to get back to its setting," she said.
The program should, however, save the utility, and ultimately the customers, money. "We estimate how much power we're going to need, and then we procure that," said Munsell. "If we find ourselves in a situation where there's a peak demand and we can't supply that, then we have to go out and purchase it," which is expensive on the open market. "If we can better manage that load for power during peak periods, then it's ultimately better for the customer in terms of keeping those costs down and also reducing the carbon footprint."
Through September 2013, implementing Summer Advantage will cost Entergy $5 million — a cost that, as of July 2012, has been passed along to customers as the "Energy Efficiency Cost Rate Rider" detailed on each bill. (For most customers, it averages $2.11 a month, according to Entergy.) Entergy Arkansas has 16 different efficiency programs, all of which are paid for in part by the consumer, and all of which have been approved by the Arkansas Public Service Commission.
According to David Lewis, another Entergy representative, high demand loads can sometimes cause transformer failures, which may result in rolling outages lasting half an hour at a time and affecting a few thousand customers. "It is very unusual to have to take this step, like maybe once every few years. This has happened once that I know of this summer, in the Stuttgart area June 29," he said via e-mail.
There's a Summer Advantage hotline to address customer questions. According to a hotline representative, customers who choose to enroll in Summer Advantage can opt out at any time and receive a pro-rated rebate. "We put the serial number on a list so that when we send out a radio signal, there's a group of houses that aren't affected. We just add that one to the group that isn't affected. ... If we need to remove it [the DCU] we can, but it doesn't end up being necessary," the representative said. Entergy's plan is to leave the DCU in place, so that next summer it can be used again if the resident chooses.
One heat and air company said the DCUs should have no negative effects on the life of an A/C unit. According to a Middleton Heat and Air customer service agent, more frequent cycling does not harm the unit, nor will the DCUs invalidate the warranty on a unit purchased from Middleton.
Entergy addresses the comfort question on its website: "During this time [a conservation event], the temperature may rise a few degrees but, if you're like most customers in similar programs, it's unlikely you'll notice the change."
(But in July 2011, just after the start of the Pennsylvania-based PECO utility's similar program, the "Upper Southampton Patch" noted that the temperature inside at least one home rose 7 degrees.)
Entergy studied similar compressor cycling programs, including those of the Public Service Company of New Mexico, Georgia Power, Gulf Power and Rocky Mountain Power, before designing its Summer Advantage. According to Entergy, 30 U.S. utilities with more than four million residential customers use a similar program.
Since 2003, Rocky Mountain Power, which supplies most of Utah's power, has been using a voluntary compressor cycling program open to both residential and business customers. One hundred thousand customers are currently enrolled, with 115,000 control devices in place. The extra 15,000 are attributed both to drop-outs and businesses with multiple units and devices. According to Jeff Hymas, a spokesperson for the company, "Participation has increased every year since its inception in 2003. Currently, the number of participating customers remains steady, and we're not seeing the same growth as in past years." In March 2010, the Utah legislature passed a bill that, among other things, would have made enrollment in this compressor cycling program mandatory. Two weeks after it passed, the governor vetoed the bill.
When Entergy has 3,000 DCUs installed in Arkansas, it will began to remotely cycle the registered compressors. By the end of 2012, Entergy expects to have 10,000 participating customers. "This program's cost effectiveness analysis demonstrates net benefits, on a per kWh basis, are about two times better than the cost of building generation facilities to provide summer peak energy in Arkansas," Munsell said.