Thousands give up control of home thermostats during a heat wave
During this week’s heat wave, utilities will urge residents to ease up on the air conditioning. But in a growing number of Southern California homes, smart thermostats are changing the temperatures automatically.
The energy-saving tactic is made possible by the growing popularity of so-called smart thermostats, home temperature control devices that are connected to WiFi. That makes it possible to control home heating and cooling systems from afar.
More than 41,000 residential customers in Southern California Edison’s service territory have given permission for thermostat companies to adjust home temperatures when electricity demand is likely to peak. That number is up from about 5,000 homes last year, said Dave Kaintz, senior manager for Edison’s product and development group.
That's still just a blip compared with the company’s more than 4 million customers throughout Los Angeles and surrounding counties.
The concept of encouraging utility customers to voluntarily lower power use during peak demand times is called "demand response," and it’s not new.
Edison residential customers have long had the option of getting lower power rates if they let the company switch off their home air conditioners during peak times. But that’s a blunt club for energy savings compared with the way the smart thermostats work. The new program has more finesse -- temperature swings are only a few degrees from a home's programmed setting.
Between homes and businesses, Edison's demand response programs save about 1408 megawatts, enough energy to power more than 1 million homes. But so far, smart thermostats account for only about 2 percent of those savings.
Under Edison’s program, customers buy and install their own WiFi connected thermostats, choosing from a list of many venders who have Edison-compatible products. Customers get a $125 sign-on incentive in the form of a bill credit when they opt into the program that gives thermostat companies permission to control home temps. The residential customers earn a small amount for each kilowatt hour they save through participation in the program. It works out to a few bucks a day.
What happens on a Power Save Day?
Edison declares a Power Save Day when heat, cold or other factors, such as a gas shortage, calls for conservation of electrical power.
On a very hot day when the savings are needed at 2 p.m., the thermostat companies will first pre-cool homes a few degrees in the hour before. Then at 2 p.m. the air conditioners will be remotely controlled to let the homes heat up two to four degrees. When the energy savings period ends, usually around 6 p.m., the air conditioner is returned to its normal pre-programmed settings.
SoCal Gas' Aliso leak triggered growth in smart thermostats
SoCal Gas’ ability to store natural gas was severely limited by the state moratorium on its Aliso Canyon gas storage field near Porter Ranch. The lack of storage for gas to run electrical power plants during heat waves led state energy regulators to impose new conditions on utilities. One was to encourage demand response programs that lead customers to voluntarily consume less energy.
SoCal Gas partnered with Edison to offer the $125 incentive. Edison puts $75 toward the incentive and SoCal Gas puts in the remaining $50, Kaintz said.
What do other utilities offer?
Los Angeles Department of Water and Power is developing its own program that would use smart thermostats to cut air conditioning use on hot days in homes where residents opt in. That could go to the DWP governing board by early next year.
SoCal Gas has a winter demand response program in which it can adjust about 400 residents' thermostats made by Ecobee and using a software platform developed by EnergyHub. The program started last year, but has not been needed to conserve gas during times of potential shortages.
SoCal Gas also has an automated efficiency program that uses thermostats from the company Nest.
In regions where residents opt in to energy saving programs from Nest, residents tend to save about 15 percent on their cooling bills, the company's product manager Will Greene said. He said about 55 percent of the company's thermostat purchasers opt in to energy savings programs that the company markets on behalf of utilities.