Fuel Cells Versus Batteries

Electric cars of some kind are likely to be the vehicle of any workable green, environmentally sustainable future. The question is only what kind of electric car will reside behind future garage doors. Currently, the electric-vehicle market is dominated by battery-powered electrics and plug-in hybrids (which are actually battery-electric cars capable of switching over to a conventional internal-combustion engine when the juice runs low while you’re on the road). But, as if a Thomas Edison lightbulb lighting up minds with innovation, there is an alternative to this technology in the works which may prove superior in many respects: the hydrogen-powered fuel cell.

A fuel cell vehicle is an electric car which is powered by electricity generated on board rather than stored in a battery. The electricity comes from a fuel cell that uses hydrogen and oxygen to generate electricity, emitting water vapor as a waste product.

The advantages of fuel cells over battery-powered electrics are partly a matter of convenience and party environmental. Manufacture and disposal of batteries have significant environmental costs. Advances in battery technology such as the development of lithium-iron batteries may somewhat reduce the environmental damage from both manufacture and recycling, but as long as batteries depend on scarce lithium, there are limits to how far this can be taken. Richard Suebi’s recent article in CleanTechBlog, “Assaulting Batteries,” described further advances in energy-storage technology that may be coming down the road, but all such possibilities remain speculative at this point. Fuel cell vehicles would simply undercut the entire battery question by producing electricity in the vehicle itself. In terms of convenience, a fuel-cell vehicle would require no time-consuming recharge, but could be refueled in a manner similar to the way it’s done with a conventional vehicle, at a commercial station carrying hydrogen gas – a “gas station” in a more literal sense of that phrase.

The chief disadvantage of fuel cells other than their relative unavailability on the market and, with current platinum-intensive technology, the high price tag, involves the storage of hydrogen gas onboard, which in current models is done with tanks pressurized to 10,000 PSI or more. This represents a certain hazard as is always the case with compressed gas storage, less so in a crash than the gasoline tank of an internal-combustion vehicle but worse than for battery-electrics using the latest battery technology.

GM has been working on a fuel-cell vehicle for over a decade. The company plans to have 1000 fuel-cell vehicles on the road over the next two years and has ambitious long-range plans to have over a million fuel-cell vehicles on the road by 2020. Toyota is also pursuing fuel-cell technology aggressively with a 2015 timetable to have a model on the market. It is likely that more refinements of the technology will be necessary before fuel-cell vehicles become practical.

Another question involves the production of hydrogen fuel itself. A promising possibility involves bio-production of hydrogen using green algae. Alternatively, hydrogen can be produced from water by electrolysis, making it as green as the way we produce electricity.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.