Rooftop thin-film panels

Even with the advance of concentrating solar power, it faces tough price competition from solar photovoltaics, the traditional flat panels that convert sunlight directly into electricity. Seen here are solar panels from First Solar which use thin-film solar cells, another technology which is also lowering prices. Despite the technical advances in solar, the one innovation which has truly caused a jump in residential solar is on the business side. A number of installers now offer solar leases or power purchase agreements, which allow consumers to lower their electricity bills with solar panels without having to buy or own the equipment.