In the next few weeks, construction crews will begin building an anaerobic digester on the Goodrich Family Farm in western Vermont that will transform cow manure and locally sourced food waste into renewable natural gas (RNG), to be sent via pipeline to nearby Middlebury College and other customers willing to pay a premium for low-carbon energy. For the developer, Vanguard Renewables, the project represents both a departure and a strategic bet. The firm already owns and operates five farm-based biogas systems in Massachusetts; each generates electricity on site that is sent to the grid and sold under the state’s net-metering…