DEXTER, Maine — Central Maine Power Co.’s new digital smart meters are so accurate they will detect minute electrical use that may have gone undetected by the old meters, but customers shouldn’t worry about their bills increasing, a CMP official said Thursday.

“It’s going to be very minute,” Rhonda Perkins, CMP’s key account manager, said of any difference in cost.

In 2009, the Maine Public Utilities Commission asked CMP to upgrade its grid and its meter system and the installation of the smart meters that use electronic data recording are part of that process, Perkins told the Dexter Town Council Thursday. CMP received $96 million in federal stimulus funds to help pay for the $192 million upgrade. The remainder of the cost will be paid over a period of 15-20 years, but ratepayers should not see any impact in their bills for the installation costs, according to Perkins.

The company has about 620,000 meters in its customer service area and about 300,000 of those have been changed over to the new meters, Perkins said. Dexter has 2,144 meters that must be changed. The new meters will automatically send information about electrical use to radio repeaters and on to the company, which will eliminate the need for meter readers.

Those meter readers displaced when the smart meters officially come on line in the spring of 2012 have been offered other jobs or early retirement, she said.

While there has been concern expressed about the radio frequency of the new digital meters, Perkins said the units actually produce a very low frequency. In fact, baby monitors, laptops and cell phones produce more frequency than the smart meters, she noted.

“Through the Federal Communications Commission, these meters were tested and deemed safe,” she said.

Once the smart meters are installed and the grid is in place, the meters will send out a signal for less than one minute per day, every day, according to Perkins. The new meters will tell the company when a power outage occurs so customers will not need to call. In addition, customers will be able to monitor their electricity use on a daily basis through their computers through a secure site.

For those still concerned over the frequency, Perkins said residential and small commercial customers can opt out of the smart meters. These customers have two alternate choices: they may have the new smart meter installed without the radio frequency card, a move that would require a one-time $25 fee and an additional monthly charge of $10.50; or they may keep their old mechanical meter for a one-time $40 fee and an additional monthly fee of $12.50 per month.

Customers will be notified before meters are installed in their areas. Perkins said customers should ask for identification when approached by CMP or its contractor VSI Meter Services.