Devices allow remote Internet control over home a/c

The catch is that TXU can adjust it, too.

The thermostat is expected to save customers as much as $150 a year on electricity charges, and possibly more, according to Sophia Stoller, spokeswoman for TXU Energy.

Remote thermostats aren't new. The devices allow a homeowner to make adjustments to a house's temperature on their computer, or an Internet-capable cell phone. Stoller used the example of having to work late, and going on-line to tell her thermostat not to crank up the a/c just yet. Because it's programmable, a person can ask for four different settings a day, for example, morning, daytime, evening and night, according to a household's schedule.

The thermostats are only available in North Texas, and only to customers who already have a broadband Internet connection, Stoller said. Stoller said the big brother aspect of the thermostat, which is that TXU can also make adjustments, shouldn't be a concern.

Customers can always adjust it back by going on-line, or by calling TXU. They can also opt out of specific days, if they know the 're going to be hosting a party that day, for example. "We're just putting it up a couple of degrees, it's only two or three degrees. A customer should not feel any difference," she said. "We're only going to be making adjustments during peak demand time, May through September, not on weekends, and only during the hours of 1 to 7 p.m., and not on any holidays like the Fourth of July."

The reason for TXU wanting to be able to cycle people's thermostats is because of the enormous strain on the system during those peak afternoon hours.

When people request the iThermostat, they must also agree to a two-year TXU Energy Conservation Program, although customers may change their energy plans at any time. The thermostats are shipped with directions, and should be simple enough to install, but TXU workmen will also come out and install it for a charge.

The offer for the free thermostats was made public about two weeks ago and already thousands of customers in Dallas and surrounding counties have signed up, she added.

"We're up to hundreds of customers signing up for this every day," Stoller said. "This is a great opportunity for customers who want to save money, to do something good for the environment, and it's free."