Tallest U.S. Building Goes Solar.

31 Mar 2011

Chicago’s former Sears Tower (now known as the Willis Tower) is set to become a vertical solar farm with the installation of a pilot solar glass project.  A new type of photovoltaic glass developed by Pythagoras Solar will be installed on the south side of the 56th floor of the tower.  The glass preserves daylighting and views while reducing heat gain and supposedly produces the same energy as a conventional solar panel.  If successful, the Willis Tower owners say that they will expand the project to cover the entire south face of the tower in solar windows (comparable to a 10 acre field of solar panels) turning North America’s tallest building into a 2 MW solar plant.

The new windows are dubbed high power density photovoltaic glass units. An internal plastic reflective prism directs sunlight onto the solar cells but allows daylight and horizontal light through.  Think of it as a louvered shade which allows for views but cuts out the harsh direct sun.

Good news for cities with precious rooftop space but lots of glass walls.

Leave a Comment Below

Leave a Reply