This is the one of the modules for the Sundance generator. It contains the windings for the generator. Notice that it is mounted to the generator with two bolts. Also notice the handles used to hold the module so it can be pulled out and put back in. The production version of the module will also contain an LED which will light up when the windings go bad. Each module of this size produces 1 kilowatt per hour. The expected life of each module is 20 years.