Red State, Green City

The solar panels sparkle on the rooftop of HelioVolt's 130,000-sq.-ft manufacturing facility. Inside, an elaborate line of printing machines, lasers, chemical baths and ovens--with help from the occasional white-coated human being--transforms a sheet of glass barely a quarter of an inch thick into a solar module in just over 2 hours. The sheets are a far cry from the thick, polysilicon-based photovoltaic panels that still dominate the solar market. HelioVolt manufactures thin-film solar panels, so called because the modules are made by depositing an ultra-thin--a few micrometers at most--layer of the photovoltaic copper, indium, gallium and selenide directly onto a glass...