do you have 240 volt power?
if you do and your energy cost is zero.
i dont really understand the power side of things yet. we just live in a normal uk house built in the 60s. will the garage support running 10x of these machines without blowing up the house lol. Noise isnt too much of an issue as we have a single detached garage at the rear of the house. but having said that how exactly noisy would 10 machines be?