Sun power's image as the province of baling-wire hippies was at odds with reality. Today's multibillion-dollar photovoltaic industry owes its existence mainly to the Pentagon and Big Oil. The first wide-scale use of solar panels had come in the 1960s: powering military satellites, which couldn't use fossil fuels (too bulky to lift into space) or batteries (impossible to recharge in orbit). By the 1970s photovoltaics were cheaper, but the industry had acquired only one major new user: the petroleum industry. Some 70 percent of the solar modules sold in the United States were bought to run offshore drilling platforms.