Business Green: Flywheel energy storage specialist Beacon Power Corporation last week announced that it has been awarded $43m in loan guarantees by the Department of Energy to help complete a storage project in New York state. Beacon Power’s storage plant, which will have a 20MW capacity, is designed to solve the problem of energy regulation on electrical grids. Grids must maintain their frequency as close to 60Hz as possible, but variations in supply and demand mean that utilities have to vary their …