Central Maine Power has started asking Lewiston-area property owners to sell pieces of their land so the electric company can complete a massive update to its power lines and equipment – the backbone of the system that supplies power to CMP’s entire service area.

“It’s sort of the I-95 or the Maine Turnpike of our system,” said CMP corporate spokesman John Carroll.

In an effort to improve reliability and head off significant power outages, CMP plans to redo a nearly 40-year-old, 400-mile swath of high capacity power lines, transformers and other equipment used to transmit and control electricity across the state. The project – dubbed the Maine Power Reliability Program – is expected to cost an estimated $1 billion and take three to five years to complete.

The swath starts south in Eliot and passes through central Maine in Litchfield, Monmouth, Leeds, Greene, Lewiston and a corner of Auburn at the Durham line. It stops in Orrington, where it connects with lines from Canada.

The high-capacity system carries electricity from generators throughout New England and Canada to distribute throughout Maine. Built in the 1960s and 1970s, the system is rapidly becoming obsolete as the population shifts, demand increases and concerns about reliability grow.

“We did a huge analysis, I think 5,000 different scenarios. And what starts to show up as loads grow over the next 10 years, as you start to test and measure with different system failures, we start finding areas that will lead to significant blackouts under certain conditions,” Carroll said. “And what we’re building against is that, those future possibilities.

CMP wants to update its power lines and equipment and add lines along the Eliot-Orrington route. To do that in some spots along the route it’ll need to obtain more land – an average of 25 to 65 feet with each addition. The company expects it’ll need to buy more than 500 parcels.

CMP has started asking people in the Lewiston-Greene area about selling. So far, Carroll said, “It’s going well.”

CMP’s purchase offers are linked to local real estate values. Although it generally needs only strips of land, the company may consider buying an entire lot if the owner is willing to sell only the whole thing.

“Not that we want to do that,” Carroll said. “But sometimes that might be the best solution.”

The company can also take a parcel through eminent domain, though its power is limited. The property cannot be near a house and the Public Utilities Commission must agree to it.

CMP has exercised its eminent domain rights twice since 2002. Before that, it hadn’t done so since the early 1980s or before, Carroll said.

“We have a pretty good history considering we have a lot of equipment and a lot of lines and we’re all over the state. We have a pretty good history of coming to an agreement with people,” he said.

Because the plan is at its earliest stages, CMP may simply alter the design of its route if it can’t get the land it wants. It is unclear how many parcels the company needs in central Maine.

Company representatives are meeting with officials from towns along the route to let them know about the project. They plan to make formal request for permits next year.

Construction is expected to start in 2009 and last three to five years.

The company is not planning to bury its new lines underground because such a project would be too expensive. Underground-construction typically costs 8 to 14 times what above-ground construction costs, Carroll said.