In an attempt to generate some good press for the troubled automaker, Toyota has announced that they will bring to market a hydrogen powered sedan in 2015. Perhaps the most surprising revelation was the projected cost of approximately $50,000, or that fact that Toyota claims such a product will be profitable. Previously, hydrogen fueled vehicles had been prohibitively expensive, costing in the hundreds of thousands of dollars to manufacture. Major automakers, including Ford, Renault / Nissan and GM have abandoned their hydrogen car development efforts in favor of electric and hybrid car programs, whose technology is both more mature and more affordable.
There are two ways to power a vehicle with hydrogen: the simplest involves converting an internal combustion to burn hydrogen instead of fossil fuel. Problems with this type of design are many; first, you need a safe containment vessel for the pressurized (and highly flammable) hydrogen gas, which adds considerable weight and consumes storage space. Next, there’s the problem of infrastructure; without a network of hydrogen fueling stations, drivers must be careful where they go in hydrogen powered vehicles. You can’t just hop on Interstate 80 and drive from California to New York without some serious advanced planning. Which leads to the third problem of using hydrogen as a fuel: although highly combustible, it doesn’t have the energy density of gasoline. In other words, a lot more hydrogen is required to give you a range similar to that of a gasoline powered vehicle.
Another way to use hydrogen to power a vehicle (and the method most likely under development at Toyota) is in a fuel cell, where reacting hydrogen with oxygen produces electricity in a manner similar to a conventional battery. Unlike battery powered vehicles, fuel cell vehicles don’t require recharging via electricity; instead, the driver “recharges” the fuel cell by adding more hydrogen. Issues with hydrogen refueling stations aside, the fuel cell design has several drawbacks. Until now, cost to produce the fuel cell elements has been prohibitively high. The fuel cells themselves are extremely fragile, and can be damaged by impact, vibration or even impurities in the hydrogen. Fuel cells are not environmentally robust, and must be kept at temperatures above freezing to function. Finally, there’s the issue of service life: current designs have been tested to approximately 7,500 service hours under ideal conditions, but a true lifespan for a road going vehicle has yet to be determined.
Although hydrogen is called the “most abundant element in the universe”, it doesn’t occur in pure form on earth. There may be a lot of it around, but energy is required to separate hydrogen from other elements it bonds with. Conventional methods of production involve the use of fossil fuels, which defeats the purpose of hydrogen power in the first place. New methods of hydrogen extraction, using wind or solar power are under development, but do not yet yield the quantities necessary to make hydrogen a viable fuel source.