The concept of air wells has been around for awhile, but it's good that they're able to keep the costs low and build it from local materials with local labor.

The concept of air wells has been around for awhile, but it's good that they're able to keep the costs low and build it from local materials with local labor. http://en.wikipedia.org/wiki/Air_well_(condenser) http://en.wikipedia.org/wiki/Air_well_(condenser)