GigaOM is reporting that T-Mobile is testing a completely solar-powered cell phone tower here in the States. The single tower — located in Chalfont, PA — generates enough power to keep the site off the grid and, at times, feed power back into the country’s aging electrical system. Pike Research estimates that 4.5% of all cellular stations worldwide will use solar or wind energy by 2014. The report indicates that although the tower does cost 2 to 3 times more than the standard, grid-powered equivalent, savings in the long run — in electricity, tax benefits, and initial setup costs — could very well make up for the difference over the life of the tower. Hit the read link for the full report.