I just came across two very cool tools for calculating the potential energy savings for implementing solar and wind power.
The first one is the In My Back Yard from the National Renewable Energy Laboratory (NREL). This tool allows you to calculate potential energy savings through solar and wind power. The savings is based on where your property is located and the information you specify for either the windmill(s) to be used (type, height, etc.) or the information for the solar panels (size, slope of roof, orientation, etc.). The output for the wind power is a little difficult for me to decipher, but for solar power the information is very easy to understand and provides data on incentives available for purchasing the technology. As for the payback, the NREL tool seems to compare the cost of the system with the utility rate you’re paying. It doesn’t seem to account that adding the solar panels in the first place should increase the value of your home.
Blue Architecture 