The second challenge is that there are relatively few filling stations equipped with hydrogen pumps. According to The National Hydrogen Association, as of 2008 there were sixty-one hydrogen fueling stations in the U.S. So even if scientists find a way to produce and store hydrogen cheaply, it would still take many years to build enough infrastructure to service millions of fuel cell powered cars. Today, as gas electric hybrids sell in greater numbers, and electric plug in cars begin to hit the market, scientists keep working on hydrogen technologies. So hydrogen may still be an important part of the clean energy puzzle. But it’s a long range solution.