I helped my friend set up a hydro power generator using water from his stream.
The budget was tight so we used an old washing machine as the generator and bits and pieces we found in his shed to build the rest of it.
This is the short version, check out the links below to see the full length version-
Part 1-    • Lifetime of Free Power from Water - B...  
Part 2-    • Lifetime of Free Power from Water. Pa...  
Part 3- Washing machine stator rewire vid-    • Free Power from Water Part 3- Rewirin...  
Part 4- Wiring and programming the plc -    • Free Power from Water - Using an anal...