Photovoltaic-cell technologies joust for position: The fabrication of solar cells has become a bona fide industry with three versions vying to dominate the marketplace

After two decades of trial and error, many researchers believe that photovoltaic cells - which convert light into electric current - are fast approaching the time when they will be ready for widespread use. Cell efficiencies have improved to the point where modules are a competitive energy source for users not connected to a utility grid. By the turn of the century, sanguine researchers predict, photovoltaics will be a cheaper source of electricity than oil. Until recently the application of photovoltaic cells has been confined to power source for spacecraft and remote communication devices, and some limited home use.