Build Your Own Vertical-Axis Wind Turbine On The Cheap - Didn't realize vertical wind turbines existed. The scale of this one and the fact that it supposedly doesn't require gale force winds to produce power makes it definitely worth looking into.
A hydroelectric generator barrel is a spinning water wheel that floats on the water surface and turns in the current. The spinning motion drives permanent magnet generators inside. It could generate enough power to light banks of LEDs and light up bridges