Q Not long ago we were reading a lot about hydrogen's role in a clean energy future, with cars transitioning from gasoline-powered engines to hydrogen-powered fuel cells. Where does hydrogen fit now in the mix with electric cars now coming on so strong?
A:Just a few years ago everyone was talking hydrogen fuel cells as the future of petroleum-free automotive transport. Fuel cell cars can run on infinitely renewable hydrogen gas with no harmful emissions. A 2005 Scientific American article bullishly reported that auto executives "foresee no better option to the hydrogen fuel-cell vehicle in the long run." Likewise, the International Energy Agency said30 percent of vehicles - 700 million cars and trucks - could be powered by hydrogen fuel cells by 2050.
But high development costs and implementation hurdles have kept FCVs out of the mainstream. And with a new crop of all-electric and hybrid-electric vehicles, some analysts wonder if the fuel cell's future is as bright as once thought.
Still, the technology is impressive, and potentially very promising. The concept was developed by NASA five decades ago for space travel and has since been used in lots of other applications. In a FCV, a stack of fuel cells under the hood converts hydrogen stored on-board with oxygen in the air to make electricity that propels the drive train. While automakers have been able to make fuel cells small enough to fit in and power a conventional-size car or truck, the price per unit is high. And the lack of widespread demand precludes cost-saving mass production. Also, a lack of hydrogen refueling stations limits the practicality of driving a FCV.
According to Richard Gilbert, co-author of Transport Revolutions: Moving People and Freight Without Oil, another big issue is energy inefficiency. Creating hydrogen gas by splitting water molecules and then converting it into electricity uses most of the energy it generates. "This means that only a quarter of the initially available energy reaches the electric motor," Gilbert said. That doesn't stack up well against, for instance, recharging an electric vehicle like the Nissan Leaf or Chevy Volt from a wall socket - especially if the electricity can be generated from a renewable source like wind or solar.
But FCVs aren't dead yet. A few dozen Californians are driving Honda FCX Clarity fuel cell cars. General Motors is part of an effort to test FCVs and implement a viable hydrogen refueling infrastructure in Hawaii, one of the most fossil fuel-dependent states. Other efforts are under way including in the United States and Europe.