Peter Hoffmann Responds to Your Questions About Fuel Cells Though there are a number of potential impediments to the broad adoption of hydrogen fuel cells in passenger cars, major automakers expect to commercialize the technology in their vehicles by 2015. Peter Hoffmann, the author of two books about hydrogen fuel cells and editor of The Hydrogen & Fuel Cell Letter, was featured in a recent interview with Jim Motavalli, a frequent Wheels contributor . Editors selected questions submitted by Wheels readers about the technology and its prospects for adoption, and posed them to Mr. Hoffman. His responses follow. Q. I heard these types of engines discharge small amounts of water as their exhaust. Will that be a problem in very cold temperatures, with puddles of ice laying around at stop lights and stop signs?- jny243, Penn. A. Fuel cell cars emit warm water vapor rather than liquid water, so it just dissipates into the atmosphere, like other exhausts. It doesn't seem to be a problem (and keep in mind that today's cars push water vapor out of their tailpipes, especially on warmup). Fuel-cell cars have been tested in cold climates, and a new hydrogen fueling station recently opened at the world's northernmost car testing facility, the Arctic Driving Center in Rovaniemi, Finland, almost smack on the Polar Circle. Q. Mercedes has experimented with hydrogen vehicles going back to the 1970s. I remember winning a bet in school over that. After reading the article in Science Times about the scientist who is closing in on producing butanol (much better than ethanol, it's more energy-dense and not hydrophilic), I'd be more eager to pursue that. - Larry, The Fifth Circle A. You're right about Mercedes. I rode in their first one, a converted internal-combustion-engined minivan, on their test track near Stuttgart back in 1975, and it ran just fine. They wouldn't let me drive it, though. It goes to show how long they have been at it and how much development time it takes to perfect what is, after all, a revolutionary new technology. Mercedes shifted to fuel cells in the 1990s, first to straight fuel cells and methanol, and then settling, like most other automakers, on hydrogen-fueled fuel cell/battery hybrid systems. About butanol: I suspect it may have to do with production capacities as well as the overriding long-term concern over global warming. The ideal situation would be to get to true zero emissions: no carbon in transport fuels at all, if we want to get to the target of an 80 percent reduction of CO2 in the atmosphere by 2050, a stated goal of President Obama, many European governments, 350.org and others. Wind power as a primary energy source for producing hydrogen, both as long-term utility storage (in aquifers, for instance) for base-load reliability and as transportation fuel, is supposed to get serious tests in Germany starting this year. That presumes the government comes through with the money - hundreds of billions of euros - which is seen as likely. Smaller test installations are already underway in Germany and elsewhere. Q. Hydrogen (from electrolysis) fuel-cell vehicles offer perhaps the lowest well-to-wheel energy efficiency of any transportation option. Most hydrogen is not produced from electrolysis, but rather through steam reformation of natural gas, which releases CO2. Why not simply burn that natural gas in a hybrid powertrain? - Alex A., Blacksburg, Va. A. It is indeed low, but I don't know whether it's the lowest. Again, in part it has to do with the need to get to 80-percent CO2 reduction to help halt global warming. If the primary source is zero-emission solar in any of its manifestations (wind, photovoltaic, solar trough mirrors) then it makes a lot of sense as a system, especially in view of the higher efficiency of fuel cells compared with internal-combustion engines. Offhand I don't know what the well-to-wheel energy efficiency is of battery plug-in electrics that derive power from coal or gas-fired plants, where the emissions are hidden further back in the chain. There have been studies suggesting electric-battery infrastructure is as costly as that of hydrogen and fuel cells. Joan Ogden, University of California Davis Institute of Transportation Studies; also, a presentation at the 2011 Toyota Sustainability Seminar by Jan F. Kreider, professor emeritus of engineering at the University of Colorado and president of Kreider & Associates, an energy consulting firm in Boulder, Colo., who said electric infrastructure's "real-end-of-the-line cost is shockingly high," five to 10 times the estimates from the Energy Department. It's not just a matter of plugging into the household 120-volt outlet; it takes hours and hours to charge batteries compared to minutes for fuel cell vehicles, range is limited compared with fuel-cell vehicles (about 125 miles max versus 300-400 miles for fuel cell vehicles) and so far, there seem to be no better batteries in sight, despite many promises. Q. Why are dual fuel system cars (hydrogen/gasoline) like the Mazda RX8 Hydrogen RE - some test vehicles are already on the road - not being pursued and subsidized like fuel-cell cars are? It seems these would be the perfect "crossover" vehicles until more hydrogen fueling stations can be built. - Englewood Steve, Englewood, N.J. A. The lack of support for dual-fuel vehicles could be politically motivated, but there's also recognition that internal-combustion engines that run on hydrogen are inefficient compared with fuel cells, and a dead end in the long run. Q. What are the maintenance requirements for a fuel-cell car? Are they harder/more expensive than gasoline or electric? - ronniel, Southern Colorado A. The early prototypes were more complex, but the industry says in the long run, once they are commercialized, maintenance should be lower: no lubricants, no coolant, no moving parts in the fuel cells (other than auxiliary pumps, etc.). Q. At this point in time the cost and energy needed to produce hydrogen fuel is extremely prohibitive, so what can be done to bring prices in line with petroleum, as well as lower the energy needs for hydrogen production? - TJ Martin, Kansas City, Mo. A. Probably time will do it, as petroleum costs go up. With more research into better hydrogen production, storage, compression and, maybe, liquefaction technologies, prices for hydrogen are likely to go down. I'm not sure hydrogen is prohibitive, at least by European standards. There's a famous picture from a couple of years ago of a hydrogen station at the Stuttgart airport with a Mercedes fuel-cell car in front: the pump price reads 0.9 euros per 100 grams, the equivalent of nine euros, or $11.81 by current exchange rates, for one kilogram, equal to a gallon of gasoline in energy content. Factoring in the roughly double efficiency of fuel cells, and you arrive at something like $6-per-gallon gasoline equivalent, not too far from what drivers in European countries pay today for gasoline. Q. Would not a reforming fuel cell be better since it could use current fuel distribution systems? - ming, Ann Arbor, Mich. A. Some researchers are working on such systems. Eric Wachsman at the University of Maryland is developing a lower-temperature solid-oxide fuel cell (350 degrees Celsius target, compared to around 800 degrees Celsius today) that could use carbonaceous fuels as well as hydrogen. It would work as a range-extender, replacing internal-combustion engines. The Energy Department hasn't been particularly interested, he says, but he has launched a start-up company. Q. Would it be reasonable to expect fuel cells to be scaled-up to power large vehicles like S.U.V."s, semi-trailers or even construction equipment? - progressiveman, Illinois S.U.V."s have been the preferred vehicles of choice for trying out automotive fuel cells by many automakers (among them, G.M., Toyota and Hyundai) because they offer the most space for installing drivetrains and other equipment. Big hybrid fuel-drayage trucks are being tested in the Los Angeles and Long Beach ports. Many buses are operating on fuel cells. A Fiat/New Holland fuel-cell tractor concept has been shown at European agricultural equipment fairs. And fuel-cell-powered construction equipment concepts have been floated by some manufacturers - Volvo, for example - as examples of future applications at construction equipment fairs. There's even a three-megawatt fuel-cell-powered switchyard locomotive being tested by BNSF, the railroad bought by Warren Buffett a few years ago.