T-Mobile harvests the energy of the sun to power its cell tower signal
The carrier is certainly aiming to score some green points, and satisfy its corporate social responsibility department, while eventually offsetting some carbon trading initiatives further down the road. It is definitely not a money-saver, since the equipment costs 2-3 times the price of a regular tower. In the long run, it will eventually pay off, though, and can also be used to feed electricity back to the grid when times are tough, or generate signal even if there is a power outage.
Now, if they only had placed this tower in Scranton, PA, we can imagine all sorts of situations for the new season of "The Office".