Doubled in 4 year?

Have you ever thought about buying a propane gennerator to produce a portion of your own energy?

If my light bill raises more than $15 from previous year... I am going around looking for what caused it.

 

I watched a thing on PBS about a year ago or more, where they built this energy effecient house and was able to completely power it by natural renewable energy sources. (wind, sun, hydro, etc) with out sacraficing any convinices. The whole house ran off batteries. The generators just kept them charged. They had wind mills for wind generators, a solar panel about 1/2 the size of a vehicle that followed the sun across the sky "like one of those old big satelite dishs." A small hydro generator in a nearby creek. They even powered a rather large electric HVAC system. It was amazing.