There is a class of people who are moved by the elegance, the aesthetics, of a design or an engineering solution. I am a card-carrying member of this class. For us, the race between the lithium-ion and fuel-cell technology for automotive energy storage is a no-brainer: lithium-ion is simpler, more efficient, has a demonstrated track record, doesn’t require platinum, and integrates more readily with the existing grid. Confidence in this belief is borne out by the fact that high-quality automobiles based on lithium-ion are in real-world production, with charging infrastructure under rapid development.
But, however clear this thinking may be, Horace Dediu points out that what comes to pass in the real world is often determined by factors beyond engineering elegance. In his Asymcar 16 podcast, he suggests that implicit in our reasoning is the assumption, an historically good assumption, that primary energy is difficult to obtain and easy to store and transport and that, in the dawning age of inexpensive photovoltaics and wind power, this equation may reverse with primary energy becoming easy to obtain but difficult to store and transport. This is already beginning to unfold in places like California as noted by the California ISO.
Summarizing from the podcast discussion, there appear to be three relevant areas: automobile energy storage; grid storage; and energy transport. Lithium-ion appears to be the winner in automobile energy storage so far and, though rife with significant shortcomings, we have an electrical distribution system that is already supporting a lithium-ion automotive storage system, but only the most rudimentary distribution system for hydrogen.
But the grid-scale energy storage piece of the puzzle is still something of a wildcard. Lithium-ion might be too expensive, or too dependent on scarce lithium, cobalt, and graphite to reach the needed scale. Perhaps electrolysis of water to create hydrogen gas could scale faster and more economically? In a world with abundant, inexpensive primary energy, the inefficiency of electrolysis and the requirement to build a new distribution infrastructure might not matter as much as the ability to scale rapidly.
So the race between lithium-ion and fuel-cell storage technologies for automobiles may not be as over as I had thought—or would like—and may be significantly influenced by which grid storage technology scales and integrates the fastest. To my mind, Ambri’s liquid metal battery approach is among the most promising, but there are many folks with eyes on this bazillion-dollar prize.
I think electrolysis/hydrogen grid-scale storage will not scale fast enough, and still put my money on lithium-ion winning the automotive race, but I’m just guessing. Horaces’s perspective is a good reminder that reality doesn’t care what we like, and that if we want to know what will unfold, we need to set our tastes aside and focus on careful observation and reason. And that the automobile energy storage race may have a few more laps to go…