State regulators have begun the process of collecting proposals for a high-voltage transmission line to serve as a conduit for renewable energy projects in northern Maine.

A state law required the Maine Public Utilities Commission to begin planning for a transmission capacity of at least 345 kilovolts to connect northern Maine to the New England power grid.

That process began Monday with a request for proposals issued by the Maine Public Utilities Commission. Those are due March 1.

A second phase of the project calls for a request for proposals for renewable energy generation projects. Those are due May 1.