Argument: It is not too energy-intensive to compress hydrogen
Amory Lovins, CEO of Rocky Mountain Institute. "Twenty Hydrogen Myths". 20 June 2003 - Myth #8. Compressing hydrogen for automotive storage tanks takes too much energy. Compressing hydrogen to fill tanks to 350 bar using standard 93–94%-efficient intercooled technology takes electricity equivalent to about 9–12% of the hydrogen’s energy content. However, most of that compression energy can be recovered aboard the car by reducing the pressure back to what the fuel cell needs (~0.3–3 bar) not with a throttling valve but with a miniature turboex. pander like a supercharger run backwards. In addition, where the compressor’s externally rejected heat can be put to good use, it need not be wasted. And compression energy is logarithmic — it takes about the same amount of energy to compress from 10 to 100 bar as from 1 to 10 bar, so using a 700- instead of a 350-bar tank adds only ~1–2 percentage points to the energy consumption, raising the compression energy from ~9–12% to ~10–13%. Modern electrolyzers are therefore often designed to produce 30-bar hydrogen, and some electrolyzers in advanced development yield 200 bar, at only a slight efficiency penalty. This can cut the compression energy required for filling a 350-bar tank by half or by three-fourths, respectively83 — i.e., to only ~3–6% of the hydrogen’s energy content. Further advances are emerging from other technologies, e.g., in nonmechanical compression, such as the electrically-driven membrane technology developed by Canada’s National Research Council.