LEXINGTON, Mass. -- Away from curious visitors' eyes, laboratory staff at a company called 1366 Technologies here are melting purified silicon in a furnace until it reaches the consistency of red-hot lava. Then they skim off wafers of silicon, the platforms for photovoltaic solar modules. This may sound simple, but it isn't being done in China, in Germany or anywhere else, says 1366 CEO Frank van Mierlo, one of the Massachusetts Institute of Technology alumni and technology entrepreneurs behind the startup firm. If it works at factory scale, 1366's process would go far toward making solar energy as cheap as coal power in this decade, he says.