Trading our gas-guzzling cars and trucks for ones that run on hydrogen gas may save not only energy but also save lives. According to a new report, a wholesale shift to hydrogen would dramatically reduce airborne pollutants, lowering health impacts ranging from headaches to heart attacks.
Most researchers have focused on the energy savings from hydrogen fuel cell vehicles, which are more efficient than those that run on fossil fuels are. But Mark Jacobson, an atmospheric scientist at Stanford University in California and his colleagues suspected that this would only be part of the story, because pollutants coming from hundreds of millions of tailpipes nationwide create the urban haze that's responsible for triggering ailments that lead to thousands of deaths a year. So Jacobson's team decided to model how the health and climate impacts would change with a switch to hydrogen cars.
Though hydrogen powered vehicles emit only hydrogen and water vapor, another energy source is needed to generate hydrogen in the first place, as well as transport, store, and compress it inside fuel tanks. So Jacobson's team compared the pollution and climate effects of generating that energy through burning coal, natural gas, or using wind turbines, as well as switching to fossil fuel powered hybrid cars. They found that each resulted in lower air pollution and health benefits. But because of its low pollution emissions, producing hydrogen from wind provided the greatest climate and health benefits, saving as many as 6350 lives a year. Hydrogen generated from natural gas came in second, and hybrid cars and coal generated hydrogen tied for third, due to their higher impact on climate, the researchers report 24 June in Science.
The new analysis is "innovative" and "an important contribution," says Jonathan Koomey, who specializes in gauging the costs of mitigating climate change at Lawrence Berkeley National Laboratory in California. The bottom line, he says, is that a wholesale transition to hydrogen fuel cell vehicles shifts pollution from individual cars and trucks to centralized plants, which are often easier and cheaper to control.
Mark Jacobson's Web site