Uh, the two times I've been in Madison for a week for professional meetings it was *pretty darn hot*. Also pretty darn sunny.
If you lived in Seattle I'd still encourage you not to do it but would admit it might *possibly* turn out ok.
In Wisconsin, I sincerely don't think so. Roast chicken in a box.
Furthermore, you will need to insulate under them for wintertime or you will get bad condensation (->humidity->frostbite), which would pretty much negate the whole 'let light in' thing then ANYhow.
Light can come in the WALLS much more safely than in the roof. Put your light-transmitting material -- glass, plexiglas, those corrugated panels, whatever -- on your WALLS.
Seriously!!!
Good luck, have fun,
Pat