Odd feature on house, what is it?!

[Alex Martin]

I am looking at a new property and came across this on the back side of the house( don't know right off hand which direction this is facing). I'm not sure what exactly it is, someone suggested solar panels but I really don't think it is. I figure before I do anything do it I should figure out exactly what it is. Any ideas?

It might be hard to see in the picture, but behind the glass is like a metal mesh running through it. It looks like whatever this is, it is built into the house.

[Thomas S.]

Passive solar heating.