Your home could be the service station of the future. Within a decade, the filling station could face competition from the natural gas,electricity and even the water supplied to homes, General Motors officials say, according to a Reuters report.Cleaner, more energy-efficient fuel cell cars and trucks, expected to begin arriving in dealerships in the next 10 years, could be powered by hydrogen derived from a variety of sources, giving the oil industry some competition for the first time."Quite frankly, the transportation sector, to a large extent, is held hostage to petroleum," said GM Vice President Larry Burns, head of itsresearch and development. "That's been the lone source of energy for the transportation sector for a century. Your home could be your source of energy, your source of power, for your fuel cell vehicle."Fuel cells use an electrochemical process to create electricity by mixing hydrogen withthe oxygen in the air around us. They offer the promise of removing the car from the environmental debate because they emit little more than water and heat, reducing the greenhouse gases and smog-forming pollutants that internal combustion engines produce.