Nissan's hydrogen-fueled X-TRAIL FCV fuel cell vehicle.
Donbraco, courtesy Flickr.

Dear EarthTalk: How is it that hydrogen can replace oil to run our cars? There seems to be a lot of controversy over whether hydrogen can really be generated and stored in such a way to be practical?
-- Stephane Kuziora, Thunder Bay, ON

The jury is still out on whether hydrogen will ultimately be our environmental savior, replacing the fossil fuels responsible for global warming and various nagging forms of pollution. Two main hurdles stand in the way of mass production and widespread consumer adoption of hydrogen “fuel cell” vehicles: the still high cost of producing fuel cells, and the lack of a hydrogen refueling network.

Reining in manufacturing costs of fuel cell vehicles is the first major issue the automakers are addressing. While several have fuel cell prototype vehicles on the road—Toyota and Honda are even leasing them to the public in Japan and California—they are spending upwards of $1 million to produce each one due to the advanced technology involved and low production runs. Toyota hopes to reduce its costs per fuel cell vehicle to around $50,000 by 2015, which would make such cars economically viable in the marketplace. On this side of the Pacific, General Motors plans to sell hydrogen-powered vehicles in the U.S. by 2010.

Another problem is the lack of hydrogen refueling stations. Major oil companies have been loathe to set up hydrogen tanks at existing gas stations for many reasons ranging from safety to cost to lack of demand. But obviously the oil companies are also trying to keep customers interested in their highly profitable bread-and-butter, gasoline. A more likely scenario is what is emerging in California, where some 38 independent hydrogen fuel stations are located around the state as part of a network created by the non-profit California Fuel Cell Partnership, a consortium of automakers, state and federal agencies and other parties interested in furthering hydrogen fuel cell technologies.

The benefits of ditching fossil fuels for hydrogen are many, or course. Burning fossil fuels like coal, natural gas and oil to heat and cool our buildings and run our vehicles takes a heavy toll on the environment, contributing significantly to both local problems like elevated particulate levels and global ones like a warming climate. The only by-product of running a hydrogen-powered fuel cell is oxygen and a trickle of water, neither of which will cause any harm to human health or the environment.

But right now 95 percent of the hydrogen available in the U.S. is either extracted from fossil fuels or made using electrolytic processes powered by fossil fuels, thus negating any real emissions savings or reduction in fossil fuel usage. Only if renewable energy sources—solar, wind and others—can be harnessed to provide the energy to process hydrogen fuel can the dream of a truly clean hydrogen fuel be realized.

Stanford University researchers in 2005 assessed the environmental effects of three different hydrogen sources: coal, natural gas, and water electrolysis powered by wind. They concluded that we’d lower greenhouse gas emissions more by driving gasoline/electric hybrid cars than by driving fuel cell cars run on hydrogen from coal. Hydrogen made using natural gas would fare a little bit better in terms of pollution output, while making it from wind power would a slam-dunk for the environment.