Alternative energy doesn't have to be high tech

Here's a story about a professor at Rutgers University in New Jersey who built a passive solar heating system in his home and hasn't paid a heating bill in 25 years. The article is at Livescience.com.

While the heating is very efficient, the article doesn't mention how the system operated in the summer and how the home was cooled and/or heat transferred away from the home. Cooling a home via alternative sources is harder than heating, since most cooling processes create heat as a by-product.