The issue is that for a BEV, charging speed is directly coupled to energy demand from the grid. Using nice numbers, if you want to charge a BEV with a 100kWh ba

The issue is that for a BEV, charging speed is directly coupled to energy demand from the grid. Using nice numbers, if you want to charge a BEV with a 100kWh battery in 6 minutes, you'd need a 1MW charger, which is a non-trivial amount of power that needs to be dispatched. Multiply this by the number of cars charging at any given time, and you have a recipe for huge demand volatility, which is a problem if our grid is going to be powered by non-dispatchable sources like wind and solar. The alternative is having chargers be so ubiquitous that everywhere you park you have some form of trickle charging, so that people living in apartments don't have to sit at a fast charger once a week. Hydrogen gets around this, because eventually it's going to be a clean source of consistent demand that takes advantage of the fact that renewables require overproduction. A country like Denmark meets 40% of its electricity demand from wind, but produces up to 140% during periods of oversupply. If Denmark wanted to produce 80% of its electricity demand with wind, and do so with 90% confidence, it will generate more than 100% of its needs on average. Even if you wanted to look at the EU instead of Denmark, the same will still apply, because in order for two locations A and B to able to cover for each other when one has excess and the other doesn't, it must also be true that there will be times where no-one has a shortage. Since we want to guarantee our ability to provide X units of power at any given time, we need the grid as a whole to almost never have a shortage in aggregate, which means we will generally overproduce. To give you an idea of the scale of this; California already curtails around 2.5TWh a year, which is enough to charge anywhere between 25 and 40 million BEVs. And that's one state, today, at relatively low-moderate renewable penetrations. It doesn't really matter if the round trip efficiency of hydrogen is lower than Li-ion, because we aren't going to have a shortage of electricity by any means. We're already throwing the stuff away.