A proposal to build a new power line in Aroostook County could be good news for local residents and the state, but only if the line brings benefits to the area and does not merely pass through it. The challenge for regulators and elected officials is to ensure that having more power make a transit across Maine benefits Maine, typically through lower power rates and a better backup supply.

Last week, Central Maine Power Co. and Maine Public Service Co. agreed to consider a new transmission line in Aroostook County. The county is now connected to New England only directly through transmission lines in Canada. A new line would improve reliability and allow more power to be sent to the rest of New England. More competition, which should mean lower rates, in Aroostook County should also be required.

In December, the Maine Public Utilities Commission rejected standard offer bids to provide residential electricity in Aroostook County because the market there is too small to encourage numerous energy suppliers to participate. The PUC had received two bids of different duration from the same electricity supplier. The new bids would have resulted in a large price increase for residential customers. Because only one company was involved, there was no way to know what factors contributed to the large price increase.

With no connections to the New England power pool, Aroostook County functions as an independent energy market. For years this has worked well, as Maine Public Service Co. has been able to sell its customers electricity for about half what customers of the state’s two large utilities pay. However, with only 37,000 customers and no connection to the New England power system, there had long been concerns that a competitive market did not exist in Aroostook County. In December, the PUC officially decided it did not and has launched an inquiry into the competitive market challenges in the county.

Also last year the PUC rejected a proposal to build a transmission line connecting New Brunswick to Aroostook County because the commission was not convinced the project would benefit Maine ratepayers.

The current proposal must clear the same hurdle. Gov. John Baldacci and New Brunswick Premier Shawn Graham have made much of their recent agreements to work together on a variety of issues, especially energy. The state and province come at energy from different perspectives.

With new generation planned in eastern Canada, New Brunswick is interested in ways to get the power to the populous New England grid. Logical routes pass through Maine and the state should ensure its residents benefit from hosting the necessary transmission infrastructure.

The cross-border diplomacy and last week’s transmission line announcement have the same aim. If done right, new projects can help both Maine and Canada.