Energy Conversion Devices, a Michigan company, is providing the solar electric system for the largest rooftop array, 12 megawatts, to a General Motors assembly plant in Zaragoza, Spain. This project uses solar devices manufactured in rolls like carpet runners. Veolia Environment and Clairvoyant Energy will lease the rooftop space from GM and operate the installation. Spain has become a center for solar installations as it offers large subsidies, 0.42 euros or 66 cents for each kilowatt hour, this is about 5 times the average cost of a kilowatt hour in the USA. Energy Conversion plans to produce 150 megawatts of cell this year and recently raised $400 million an dannounced plans to build cells for 1 gigawatt or 1000 megawatts. Solar arrays on houses are only a few kilowatts and 1 megawatt can run about 1000 window airconditioners simultaneously while the sun is shining.