DIY Water Systems
This free and open source turbine can be built for half the cost of a 120 watt solar panel, and will produce about ten times the power (5kWh with 3m drop and 35 l/s flow) per day. It can be plugged into any appropriate waterway without the need for earthworks, and uses only basic off the shelf and recycled materials, and simple hand tools.
Credit OpenSourceLowTech