As reported in an article from Germany’s Der Spiegel, BMW’s Hydrogen 7 consumes almost 50L of the clean fuel to drive just 100km/h. When you factor in that hydrogen is in scarce supply and producing it requires vast amounts of electrical-energy, then the Hydrogen 7 is not as ecologically friendly as it first seemed. Further, storing the volatile energy source also requires energy and money. The fuel is kept at -253 degrees Celsius, a process that uses up to one-third of the stored fuel.

The bulk of hydrogen commercially sold is generated primarily from petroleum and natural gas, meaning that in effect, the Hydrogen 7 puts about as much strain on the environment as a heavy truck with a diesel engine.

Other carmakers question BMW’s decision to develop combustion engines that run on hydrogen. A Volkswagen researcher, Frank Seyfried, has labeled the idea as “non-sense,” but BMW’s chief developer Klaus Draeger thinks there are still benefits to relying on the combustion engine, adding that “it's the only engine that meets our requirements in terms of dynamics." Read our previous report on the Hydrogen 7 by clicking here.