Solar Hot-Air Collectors
Solar electric panels remain cost-prohibitive for many homeowners, and it may not be feasible to install enough solar electric panels to cover your heating needs. A cheaper and simpler solution is a solar hot-air collector, which can be mounted on a roof, wall or even in the back yard. Solar hot-air collectors are essentially a tempered glass panel, insulation panels and a metal collector plate layered inside an aluminum frame.
An electric fan circulates air from the house through the collector and back into the home. On sunny winter days in cold climates, the metal plate heats up the air and increases the indoor temperature, offsetting some of the furnace's energy use.
A 2007 case study in Home Power magazine estimated that a homeowner can recoup an initial investment of $4,000 within eight years through lower natural gas bills. After eight years, he would be pocketing an estimated $500 in additional savings per year.
A solar hot-air collector also could cost far less than $4,000. Mother Earth News magazine offers detailed plans for a DIY solar hot-air collector that you can build in about an hour for around $40.