@ John Galt 1: This assumes direct drive. What about Archimedes screw or water rotor that can work in a slow moving stream. A ram pump could move water to a higher elevation say to a cistern or pool and even with a couple of feet of head can do respectable work charging a bank of batteries. This is dependent on proximity to water, of course.
If one can build a water wheel, then one can build a wind turbine (Darius or squirrel cage). If air flow is an issue, assist with a Trombe wall and a vortex air nozzle to give it a little oomph.
Don't mind me. My mind likes to wander about from time to time.