Bangor Hydro has been given the green light on a project to build a transmission line across Eastern Maine. The Maine Public Utilities Commission gave its unanimous approval Thursday. It will stretch 42 miles from Ellsworth to Harrington, and cost 68 million dollars. Lisa Martin, Manager of Transmission Development at Bangor Hydro says it’s a necessary investment to improve the power grid in Downeast Maine. “It’s first and foremost a reliability project. It creates a redundant feed to that region. It’s currently fed by a single line, so this will create a loop system which is much better for reliability.”Construction is expected to begin in early 2011 and will take about 18 months to complete.The cost will be shared among rate payers in New England, so Martin says Bangor Hydro customers can expect just a small increase in their bills.