Interesting system that this fellow built.
Notice how silent the engine is until he opens the cabinet.
175 Engine with Asynchronous motor/generator backfeeding the grid network
https://www.youtube.com/watch?v=7ZkDZQK8kIQ (https://www.youtube.com/watch?v=7ZkDZQK8kIQ)
Here is the direct translation of the video description...
-2007, soon 14000 operating hours
-Engine cooling plate exchanger, pump Grundfos UPS25/40, exhaust gas heat exchanger, water-cooled -asynchronous generator 7.5 kW
-Control = LOGO!
-Network analyzer Janitza
-Network monitoring: voltage relay, frequency relay, reverse power relay
Things are sure moving around inside that box.