SDG&E's installation of energy-tracking "smart meters" is expanding across North County.

Escondido residents began getting the meters in April, and 50,000 have so far been installed in the city, said April Bolduc, spokeswoman for the utility. The rest of North County will follow over the next several months.

About 200,000 will be installed in North County by year's end, and the remaining installed in North County by April of next year.

In August, the utility began installing the smart meters in Fallbrook and San Marcos. From now until the end of the year, installation will begin in Rancho Bernardo, Vista, Ramona, Oceanside, Bonsall and Camp Pendleton.

In January 2010, Cardiff, Carlsbad, Del Mar, Encinitas, Rancho Santa Fe and Olivenhain will begin receiving the meters. Those installations, and all others in North County, are scheduled to be completed by April, 2010.

Customers will be contacted by mail a few weeks in advance, Bolduc said, but they won't be told the actual day of installation, because the schedule is subject to change.

"We just ask that they have their gate unlocked, and allow us access," Bolduc said.

The installers will knock on the door before replacing the meters. If nobody is home, they'll leave a note explaining what was done.

The state has ordered all utilities to replace existing meters with smart meters as part of its energy conservation program. The costs for the meter will be included in the SDG&E rate structure and will not appear as a charge on customer bills.

SDG&E wants customers to shift some energy-consuming use, such as laundering clothes, to off-peak hours, reducing the need for more power plants to handle peak loads. Companies are introducing a plethora of hardware and software devices that work with the smart meters.

The meters allow two-way communication between the utility and the customer, which the utility expects will help customers better manage their energy use. They'll enable customers to check their energy use online. For those who wish it, Google is providing free energy management tools.

More information is available from the utility at http://www.sdge.com/smartmeter or by calling 800-411-7343.

SDG&E's smart meters, made by Itron Inc. of Liberty Lake, Wash., were first tested in the San Diego community of Tierrasanta, beginning in July 2008.

Installation in the rest of SDG&E's service area is scheduled to be completed by December 2011.

SDG&E's service area covers San Diego County and southwest Orange County north to Dana Point.

Call staff writer Bradley J. Fikes at 760-739-6641. Read his blogs at bizblogs.nctimes.com.