You may want to consider buying or building a wind generator to power up some deep cycle batteries instead . You didn't mention the distance from the camp to the bridge site , but some voltage drop would be unavoidable . A simple Arusha style windmill generator can be constructed from a car alternator and some spare parts , golf cart batteries would store enough juice for simple low volt lighting and other low drain items .Here's where you can find just about anything you'll ever need to know about being self sufficient , including how to construct solar , water , and wind powered devices: http://www.motherearthnews.com/recent/Homesteading_and_Self_Reliance/