The U.S. Department of Energy has set a goal of reaching less than $1 a watt—not just for the solar panels, but for complete, installed systems—by 2020 (see “Why Solar Installations Cost More in the U.S. than in Germany”). And it is possible the solar industry will hit that target even sooner than that. If so, that would bring the direct cost of solar power to six cents per kilowatt-hour, which is cheaper than the average cost expected for power from new natural gas power plants. (The total cost of solar power, which includes the cost to utilities to compensate for its intermittency, would be higher, though precisely how much higher will depend on how much solar power is on the grid, and other factors.)
Also, researchers at the National Renewable Energy Laboratory have made flexible solar cells on a new type of glass from Corning called Willow Glass, which is thin and can be rolled up. The type of solar cell they made is the only current challenger to silicon in terms of large-scale production—thin-film cadmium telluride. Right now such solar cells are made in batches (as are silicon solar cells), but the ability to make them on a flexible sheet of glass raises the possibility of continuous roll-to-roll manufacturing (like printing newspapers), which can reduce the cost per watt by increasing production.
Print me up a batch!