Former Sears Tower Will Generate Power With Solar Windows

Chicago’s Willis Tower, formerly known as the Sears Tower, will replace some of its outdated windows with energy efficient panes that also generate solar power.

Built in the 1970′s, when the idea of energy conservation seemed laughable, and bigger always meant better, the Willis Tower was constructed with single-pane windows that leak around the edges and let in hot air in summer and cold in winter, lights everywhere and inefficient electric heating throughout.

The pilot project, to be deployed on the south facing windows of the Willis Tower’s 56th floor, uses a building integrated photovoltaic (BIPV) solution that has the potential to expand to a surface area allowing over two megawatts of solar power generation.

Developed by Pythagoras Solar, these optically-enhanced solar window are the first to deliver energy efficiency, PV power generation, and transparency in a standard form factor that is easily integrated into conventional building design and construction processes.

“We are incredibly proud to be considered to contribute our part for the ‘greening’ of the tallest building in the Western Hemisphere, the iconic Willis Tower,” said Gonen Fink, Co-founder and CEO Pythagoras Solar. “With its combined benefits, our technology is set to provide Willis Tower with a valuable tool that will help move it toward its energy efficiency goals.”

In early 2010, it was announced that owners of the Willis Tower would invest about $200 million to $300 million to upgrade its energy efficiency, including an overhaul of its 16,000 inefficient windows.

The Tower’s 1451-foot height contains space for enough power-generating windows to be comparable to a 10 acre solar power plant.

Related Reading:

One Of The Tallest Buildings In The World Gets A Green Roof

Empire State Building Switches To 100% Renewable Energy

U.S. Army Officially Adopts Green Building Practices

via Gizmag and inhabitat

Image Credit: Flickr - functoruser


Benten B.
Benten B2 years ago

Highly vigorous blog, I liked that seo tool

Matthew A.
Matthew A7 years ago

There is no point in putting solar windows on the north side of a building where they will never receive any sun. The pole implied that Willis wasn't installing as many panels as economically possible.

joanna e.
joanna e7 years ago

All big buildings should have to make their windows solar panel windows. At least to run their air conditioning and lights. It would save everyone a huge amount of energy costs.
Going for a drive at night shows how many big buildings rely on security by leaving their lights on all night.

Ken Decker
Ken Decker7 years ago

Tami has got it right. Lower floors will be shaded by surrounding buildings. Put them where it does the most good.

Jimmy Spyder
Jimmy Spyder7 years ago

Yes!!! This is awesome!!! And when other city planers see the savings, they will all follow in there foot steps!!!

Samantha T.
Samantha Trosky7 years ago

I am so proud to be from Sweet Home Chicago! The prevous mayor of 22 years, Richard M. Daley had his share fo flaws, but he worked very hard to be green. As of today Rahm Emanuel is the new mayor, so we'll see what he does!

Tami Kennedy
Tami Kennedy7 years ago

Had to vote 'no' on the full replacement with solar windows. Thermal efficient windows yes, but there are many window where the shade of neighbor buildings and angle of solar incidence would preclude the window from effective power generation.

Robert O.
Robert O7 years ago


Carol C.
Carol Cox7 years ago

a TOTALLY green building? maybe not, but water condensation from the A/C units can be used for the bathrooms if collected in a tank.... and will these windows be efficient in Chicago's very cold winters?... The government should make it mandatory to use green technology in all new buildings...and homes and schools...

Vera Y.
Vera Yuno7 years ago

Chicago, always at the top of the evolution