Investors along Sand Hill Road in Menlo Park are pouring money into solar nanotech startups, hoping that thinking small will translate into big profits.

Both inventors and investors are betting that flexible sheets of tiny solar cells used to harness the sun’s strength will ultimately provide a cheaper, more efficient source of energy than the current smorgasbord of alternative and fossil fuels.

Nanosys and Nanosolar in Palo Alto — along with Konarka in Lowell, Mass. — say their research will result in thin rolls of highly efficient light-collecting plastics spread across rooftops or built into building materials.

These rolls, the companies say, will be able to provide energy for prices as low as the electricity currently provided by utilities, which averages $1 per watt.

Other uses of nanotechnology foreseen by Konarka, Nanosolar and Nanosys include form-fitting plastic batteries for electronic devices like cell phones and laptops.

While all three companies provide prototypes for large corporate research labs and government agencies, company representatives and investors are reticent to predict when nanotechnology-powered solar systems will be commercially available. Industry watchers, however, say that achieving mass production of these products may take five years or longer.

“We take the long view, although we’re not averse to having products very quickly,” said Bryan Roberts, general partner at Venrock Associates in Menlo Park, a leading Nanosys investor. “Whenever you’re developing a novel technology platform, you’re looking at a four- to six-year time frame rather than a three- to four-year time frame.”

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