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Fuel cell cars
A fuel cell vehicle is essentially a hybrid vehicle that is powered by an electric motor, which gets its power from a fuel cell stack rather than an internal combustion engine, as in today’s hybrids. While the internal combustion engine gets its energy from gasoline, the fuel cell stack gets its energy from hydrogen. The hydrogen is combined with oxygen to generate electricity, which is in turn directed to the electric motor.
Vehicles with this type of propulsion system are much more energy efficient than gas- or diesel-powered (internal-combustion) vehicles. The most efficient internal combustion engine has about 30 percent efficiency rate, meaning that 70 percent of the energy generated from the engine is lost as heat. Fuel cells, on the other hand, deliver from 40 to 70 percent efficiency. What’s equally impressive is that the only emission from a fuel cell is water. Internal combustion engines, on the other hand, produce emissions that cause smog as well as carbon dioxide, which contributes to global warming.
There are only a handful of fuel cell vehicles in use today because the technology is still being developed. In addition, there are relatively few fueling stations with hydrogen.
Making hydrogen
One of the biggest issues facing the auto industry is how to cost-effectively produce and deliver the hydrogen fuel that would be required to make mass production of fuel cells realistic. Despite the fact that hydrogen is the most common element in the universe, it is often bound with other common molecules, such as water, methanol, natural gas, or even gasoline. As a result, the hydrogen must be extracted from its primary source through a process that breaks the hydrogen bond with the other element(s). Currently, the most common way to produce hydrogen (which is used as a power source in various industries) is to extract it from natural gas, using a steam reforming process. Water, wind, solar, and biomass (plant material, vegetation, or agricultural waste that is used to produce fuel) are all possibilities for generating some of the hydrogen supply, in much the same way that these clean resources provide some of our electricity now.
Storage problems mean short range
Another issue is how to store enough hydrogen onboard a vehicle to provide a cruising range similar to the 500-550km range of today’s vehicles. Currently, fuel cell vehicles run on pressurized hydrogen. In theory, to increase the driving range, the hydrogen must simply be placed under greater pressure, allowing more of it to be stored in the same tank. But, as one can imagine, the concerns for leakage and other problems, especially in the event of a collision, grow as storage pressure increases.
Despite the lingering bad reputation that hydrogen may have received from the Hindenburg blimp accident in 1937 (although it was later determined that hydrogen was not the cause), hydrogen requires about the same level of safety precaution as gasoline.
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