Why hydrogen won’t be the fuel of the future, but it will be a vital chemical input

Since the invention of the Grubb–Niedrach fuel cell in 1958, which was used in NASA’s Gemini missions, hydrogen has been touted as the fuel of the future. Advocates of hydrogen bemoan the lack of investment, but they are convinced that hydrogen vehicles are just around the corner and every electric utility will be generating hydrogen for energy storage within a decade. Despite all the hoopla, the imagined hydrogen boom never seems to arrive. Instead, it remains the perpetual domain of venture capitalists and vague long-term plans that are unlikely to ever come to fruition. It is necessary to do the math to understand why businesses aren’t investing in hydrogen in a major way despite decades of generous government subsidies and grandiose plans.

The fundamental problem with hydrogen is the amount of energy which is lost in its creation and conversion back to usable energy. If creating hydrogen from water, first between 30% and 37% of the energy is lost in the electrolysis to split H2O into H2 and O. Then roughly 10% of the energy is lost in compressing and storing the H2 and even more is lost if the H2 is liquefied by cooling it to under −253°C (−423°F). If compressed and transported via truck to a hydrogen fueling station, roughly 20% of the energy will be lost. Then, the hydrogen is passed through a fuel cell, such as a proton exchange membrane (PEM) in an automobile, an alkaline fuel cell (AFC) in a submarine, a phosphoric acid fuel cell (PAFC) in a commercial building’s generator or solid oxide fuel cell (SOFC) at a power utility that also needs both electricity and heat. The fuel cell splits the H2 molecule into two hydrogen protons (H+) and two electrons (e-). Then combines them with oxygen (O₂) molecules from the air to create water and free electrons. One O₂ molecule and two H₂ molecules will generate 4 free electrons for electricity:
   2H₂ + O₂ → 2H₂O + 4e-
In this conversion from hydrogen + oxygen to water + electricity, phosphoric acid fuel cells lose 60% of the energy, molten carbonate fuel cells lose 50%, and alkaline and solid oxide fuel cells lose 40%. Proton exchange membrane fuel cells lose between 30% and 40% of the energy, so the fuel cells in automobiles are relatively efficient, but the membranes are expensive and they wear out too fast for use in a power plant.