Are electric drivetrains the way of the future, or are hydrogen fuel cells a better answer? That depends entirely on whom you ask, and if you were to ask someone from Toyota, they’d be sure to expound on the supposed merits of fuel cell vehicles. But ask Elon Musk, and he won’t mince words as he tells you exactly what he thinks of hydrogen “fool cells.”

At last month’s Automotive News World Congress, Musk was invited to speak to the assembled press and industry magnates to discuss Tesla Motors, as well as the auto industry as a whole. While Musk was pleased to see other automakers, like General Motors, getting more involved in building electric vehicles, he still takes issue with cars like the Toyota Mirai, which rely on inefficient fuel cells to store energy for transportation. In the past Musk has straight-up called fuel cell vehicles “bullshit“, and he has yet again made a compelling case for why he feels that way.

Transcribed from the video above:

“Hydrogen is an energy storage mechanism. It is not a source of energy. So you have to get that hydrogen from somewhere. if you get that hydrogen from water, so you’re splitting H20, electrolysis is extremely inefficient as an energy process…. if you say took a solar panel and use the energy from that to just charge a battery pack directly, compared to try to split water, take the hydrogen, dump the oxygen, compress the hydrogen to an extremely high pressure (or liquefy it) and then put it in a car and run a fuel-cell, it is about half the efficiency, it’s terrible. Why would you do that? It makes no sense.”

That doesn’t even bring into account the various problems building an all-new infrastructure, as well as the environmental impact of sourcing hydrogen from natural gas, currently the most popular way to produce vehicle-grade hydrogen. Of course, try explaining that to Toyota, which insists that the primary benefit of fuel cell vehicles over EVs, fast refilling, is well worth the inefficiencies and other shortcomings.

Elon Musk obviously has a different opinion though, and so far his argument makes a heckuva lot more sense if you ask me.

But what say you ardent hydrogen fuel cell defenders?