As in years past, fuel cell-powered vehicles are the technology of the future, according to a report published on Thursday by the U.S. National Academies.
Despite a great deal of technical progress, the study concludes that fuel cell vehicles will only make a significant dent in oil consumption and greenhouse gas emissions with decades of coordinated government policies and commitment from industry.
The primary barriers to adoption are high costs and the absence of an infrastructure to distribute hydrogen, the report said, which was commissioned by Congress and sponsored by the Department of Energy.
Fuel cell vehicles use hydrogen as a fuel and emit water vapor and heat. In a fuel cell, the hydrogen passes through a membrane to produce an electrical current to power the car.
In 2003, President Bush announced a $1.2 billion initiative to encourage development of hydrogen production technology and fuel cell vehicles.
Fuel and auto companies have invested in them as well by creating cars and setting up a handful of fuel stations.
The authors said that the best-case scenario would result in 2 million fuel cell vehicles by 2020. Adoption could increase rapidly thereafter if products were competitive on cost, the study found.
To move completely off oil and onto hydrogen fuel would require a hefty investment: $55 billion from government and $145 billion from industry between 2008 and 2023. "To put these numbers into perspective, the government subsidy for ethanol fuel could grow to $15 billion per year by 2020," according to the report summary.
How much hydrogen fuel cell vehicles reduce greenhouse gas emissions depends on how the hydrogen is made.
A Shell station in Los Angeles, for example, uses an electrolyzer that converts electricity made from renewable sources to hydrogen, but that approach doesn't scale to very high volumes, according to Shell.
The National Academies recommended a "portfolio approach" of pursuing different transportation technologies, including fuel cells, biofuels, and fuel efficiency.