Joke: At times, a large capacitor bank could be useful, especially when someone turns on a spot-welder, shutting down the breaker!
Now, back on topic, how much energy would the most energy-consuming machine used at competition take? Would it be a mill, consuming 500 Watts, drill consuming 60 Watts or something along those lines? Has anyone brought a UPS with them to give power as soon as power goes out accidentally?