The first thing I would think of would be a power generator. There are differenty types (gas, battery, etc). But of course, those coat at minimum few hundred dollars. The one time I really needed electricity, I had a car power adaptor/inverter. Something like this:
http://b.cdnbrm.com/images/products/...c_inverter.jpg
I had to put together enough extension cord to make it long enough to reach where I needed. But it did the job.
Is this type of things you're looking for?