Windmills
I would like to see these windmills made of the cheapest stuff you can find that won't break, and to run best on low winds, but remain undamaged by high winds. they might even add a rainwater collection and turbine system to increase power and efficiency.
For example, these turbines cost perhaps $10,000. This is a large windmill and the price is dramatically large. I have seen small windmills in the genre of $500. I'd like to see them drop down to $200, be made of ultralightweight stiff plastics or perhaps a corn starch gel for light blades for ease of spin. I want rain catchers with optional basin. They will have a simple alternator generating AC or DC current, and that should either feed directly into the house line, because the house is usually using power of some sort and the dial is spinning. Otherwise it can go unused or charge up a smallish Liiion battery, which can also trickle into the house later.
The setup would be a $50-100 workman job taking under an hour with all components, and the machinery would cost ~$200 and the optional battery a similar price.
Also, I'd like to see in-home biofuelcells and water fracturing. See below for details.