Natural gas burns relatively cleanly, and thanks to new extraction technologies, there is plenty of it. But few cars use it; most of the more than 150,000 U.S. vehicles running on natural gas are still trucks and buses. One reason is that natural-gas-powered cars would need a much bigger fuel tank—perhaps filling the entire trunk as well as current gas-tank space—to achieve the range that drivers are accustomed to getting from gasoline. A given volume of gasoline contains more than triple the energy found in an equal volume of compressed natural gas. Now scientists at the University of California, Berkeley, and other institutions on both sides of the Atlantic have come up with a new technology to pack more natural gas into a small space without the very high pressure or very low temperatures that are normally required. The result may be smaller and lighter tanks that are better […]