Awnings: Time to Bring Them Back
by Lloyd Alter, Toronto on 09.17.07
After Gutenberg shows the building on the right, with sunshades made of photovoltaic panels. He notes that "shading can generate electricity while reducing solar heating in the summer, which cuts cooling loads and glare. To reduce cost, such shading makes use of thin film, photo voltaic laminate systems."::After Gutenberg
Emily Lloyd of Columbia University notes that awnings used to be common in New York. "Canvas awnings enjoyed widespread use in the days before air conditioning. They were found on many residential buildings on the east, west, and south facades to shade the apartments from the sun. The armature was almost always retractable. The material was canvas, available in many colors, and frequently striped. Only a few buildings have any surviving awnings. Others have traces of awning hardware still visible." ::Framework for Planning
What could be more logical? Instead of paying to cool, why not keep the heat out in the first place? And make it modern by covering it with solar panels, controlling the sun and generating electricity at the same time. Time to bring back the awning.
What a perfect way to combine two necessary environmental concerns: shade for workers and electricity for the AC!
How about office buildings where the windows ACTUALLY OPEN UP. People should take responsibility for their lives. If they fall out, it's their fault.
Great idea. How about photovoltaic carports in uban parking lots? Keep your car cool, too.
Something that should be available now is solar louvers - with a horizontal orientation of the slats you can simply tune their tilt throughout the day and year to maximimize output.
Interstingly regular glass doesn't have much impact of PV cells so you could also make solar blinds - as the article points out, not only does this type of solution generate electricity, it also blocks incoming light and reduces unwanted solar heating.
The great thing is almost everyone can add stuff to the inside of their windows without planning permission or problem neighbors complaining about it. Furthermore everyone has windows - but not everyone has a roof - if you're north facing it wont be that great but if its south then so much the better.
Louvers mounted on the exterior of a building could actually easily be made to tilt in two dimensions optimizing their generating power. Then when you want to make them "disappear" you can just tilt the slats to 90 degrees so they are hardly visible.
The only thing I didn't figure out was where to get long thin strips of PV material from - I guess the new thin-film stuff would work but isn't it a) more expensive and b) less efficient?