Tallest Skyscraper in the US to Become a Vertical Solar Farm

The former Sears Tower, now the Willis in Chicago, will be retrofitted with new solar technology in the form of transparent glass windows that generate energy that will be used to operate the building.
http://www.grist.org/article/2011-03-22-tallest-skyscraper-in-u.s.-will-cool-itself-with-a-vertical-sola