May 11—STONINGTON — A Virginia firm has proposed to build an energy storage facility off rural Prentice Williams Road in Old Mystic.Scott Connuck, the senior project developer for East Point Energy of Charlottesville, Va., outlined the project to the Economic Development Commission on Tuesday night.Connuck estimated that the project, which takes electricity from the adjacent Eversource power lines and stores it in batteries for later sale and use, would be worth tens of millions of dollars. He said East Point Energy would be seeking a tax abatement from the town for the project.After listening to the plan, EDC members agreed to support the project and work with East Point to craft a development agreement so the town is competitive with other communities that might be trying to lure the project to their town. Residents would have to approve any tax abatement at a town meeting.The…