Electric Power Gutters
This plastic replacement downspout would feature small directional water wheels in the gutter and small generators wired together with weather proof wiring on the outside of the downspout. The most electricity would be produced if each descending waterwheel was only allowed to spin in the opposite direction the wheel above it would spin. The generators would have alternating polarity in their generating magnets to create a DC current. This would save an unknown amount on your electric bill, depending on how much it rains. The top of the gutter would need a guard to stop leaves and other debris from entering.
Reward: Installation on a moderate house of my choice.