An off-grid solar (photo-voltaic) electric power system is an ideal prep for modern survival in that it can partially or totally relinquish you from dependence upon other systems, which themselves are vulnerable to disruption or breakdown.
How to build a simple, inexpensive vertical-axis wind turbine The Zoetrope is a vertical-axis wind turbine (VAWT) made from materials commonly found at your local hardware store and a few easily purchased online, and Applied Sciences
Solar Panels- We've looked into making these before, maybe it's time for me to get on him about actually doing it so we can save some money on electric! Zack science project for fifth grade?- does this work?
Did you know, you can use common bubble wrap as insulation for windows? I had heard of this bubble wrap trick to save energy before, but had never actually gotten around to trying it. Not for every window, but just an idea to consider.