You need to cover all your energy needs at Burning Man, be it solar (recommended!), wind or generators.

Many camps with huge energy needs bring rental generators, however, smaller ones often benefit from a solar + battery set up.

About generators: according to the BM Journal :

You should first consider environmentally friendly energy solutions, but if you do choose to bring and share a generator, please be considerate of others by following these guidelines:

Bring the quietest generator you can afford, and the smallest that will meet your actual needs. Larger generators are more difficult to transport, use more fuel and create more pollution. Don’t run your generator late at night or early in the morning. Place the generator as far from other camps as possible. Cover your generator with a sound shield or baffle. Do NOT bury it to shield the noise. No matter how well it is filled afterwards, the hole leaves a tremendous gouge in the playa. Make sure people can’t trip over any power cords.

I am a big fan and believer of solar at the playa. Wind does not work as well as expected since the Black Rock City does not have consistent winds. Although some large camps, such as the Alternative Energy Zone, use wind successfully.

Here is a good selection of generators, batteries, solar panels, solar kits and wind turbines.