Ultra-thin solar cells that can be “peeled off” from larger pieces of silicon like delicious fruit roll-ups could be the key to making solar competitive with coal, say researchers at MIT. Once solar costs about half what it does now, say the scientists, rooftop panels will be generating electricity at about 6 cents per kw/h, which is comparable with coal-fired electricity in pretty much the entire country.

The report, from researchers at MIT led by Tonio Buonassisi, a professor of mechanical engineering and manufacturing, identifies early-stage technologies that, if employed together, could reduce the cost of making solar panels to 52 cents per watt. Currently, the cost is over a dollar per watt. At 52 cents per watt, assuming similar cost reductions for installation and equipment such as inverters, solar power would cost six cents per kilowatt-hour in sunny areas of the U.S.—less than the average cost of electricity in the U.S. today.

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