Chicago's Willis Tower To Become Vertical Solar Farm 227
An anonymous reader writes "The tallest building in the United States is set to become a soaring vertical solar farm, as Pythagoras Solar just launched a project to emblazon the building's glass façade with transparent photovoltaic panels. The new windows, dubbed high power density photovoltaic glass units, are a clever hybrid technology that lays a typical monocrystalline silicon solar cell horizontally between two layers of glass to form an individual tile. An internal plastic reflective prism directs angled sunlight onto the solar cells but allows diffuse daylight and horizontal light through. The high-profile project will begin on the south side of the 56th floor and could grow up to 2 MW in size — which is comparable to a 10-acre field of solar panels."
Sears Tower (Score:5, Informative)
The building is now and forever will be called the Sears Tower. No locals call it the Willis Tower. No non-locals should either. It's a landmark and a piece of architectural history. Like the headline says, it is "Chicago's." In this sense, it will always belong to the public, and the ability of some random foreign insurance firm to finagle some temporary naming rights will never change that.
Re:Transparent? (Score:5, Informative)
Re:Transparent? (Score:4, Informative)
If they are transparent, how can they capture the light and convert the photons to electrons?
For the same reason your car windshield is transparent, but your Transitions glasses won't darken.
Re:Sears Tower (Score:4, Informative)
And here I always thought Chicago's John Hancock [wikipedia.org] building, which was built first, was known as the John Hancock.
Re:Great (Score:4, Informative)
Only if the net output of the solar cells over their projected lifetime exceeds the energy costs to manufacture them and affix them to the side of the building.
Which, since they are conducting an extensive remodel [earth911.com] of the building to improve energy efficiency including replacing the single-pane windows anyway, they most likely will, that makes it a good decision.
Just because something can be done doesn't mean it should be -- a good engineer looks for the most efficient means of accomplishing the objective.
Exactly, and that often means making use of multiple techniques in concert, including some smaller optimizations that nevertheless contribute to the overall objective, and ideally take advantage of changes you're already making. For example, you might see that one of the biggest improvements you can make to the building is to replace all the old poorly insulated windows with new efficient ones. And then you can look at whether or not in-window solar would be worth it in the context of having already decided to replace all the windows.
Re:How much offset? (Score:3, Informative)
Chicago is actually named the "Windy City" thanks to their politicians, not their weather. Lots of cities are windier.
Re:Great (Score:4, Informative)
Re: Energetics of solar panels. Modern panels "pay" for themselves about 10-15 times over.
See Permanently dispelling a myth of photovoltaics via the adoption of a new net energy indicator [cam.ac.uk]
In the case of a building which requires windows I would suggest only counting the solar cell manufacturing cost as the glass and installation cost happen regardless. Unless said building didn't require the windows to be replaced, in which case it's valid to count it.