Figure about 100 watts of juice, maybe a little more, out of somebody of average fitness. Maybe for about an hour per average person. Can you line up enough generator and volunteers to make that worthwhile?

How about batteries? Do you suppose the authorities have or will make up a prohibition against people carrying batteries on & off the site? If you can, maybe it's practical to carry batteries to & from an outside grid-source charging station. This may give you enough for a few lights and laptops. Even with pedalers, you may want batteries to even out power when the pedalers sag or change places.

Forget cooking with electricity, no practical way to do it with batteries or pedaling I think. Not enough power.