> it has really poor energy/l

Compared to fuel yes. Compared to batteries, even at relatively low pressures, I think hydrogen still wins even by volume, and at higher pressures it's an order of magnitude difference.

> In Europe, battery powered trucks can carry a heavier load than diesel trucks.

You mean legally? If we're discussing which option is technologically superior long term, then it doesn't really make sense to argue based on arbitrary laws today. Is there a particular retionale behind the law that would make sense for electric trucks but not hydrogen ones?

> Green hydrogen is always going to cost about 10x as much as electricity.

Possibly, but as more renewable energy sources come online, the problem is going to change from "can we produce enough energy?" to "is the energy available at the right time and place?". Electrical energy is very difficult to store and transport in any significant quantity. We already have to turn off renewables sometimes because they're simply producing too much power when we don't need it. That power may as well go to creating hydrogen than doing nothing.

I don't know that hydrogen specficially will be the long term solution either (after all, something better could always materialize) but current battery technology is definitely not a panacea.

> ... is necessarily a lot less efficient than using than skipping 4 of those steps to charge a battery directly.

High battery/payload weight ratio means you need more energy to get where you're going, which is not typically considered when comparing the efficiency of batteries to hydrogen. Batteries also take a lot of energy to manufacture in the first place, and have a limited lifespan, which is also rarely considered. I think that with some minor efficiency improvements to a couple of steps, and a lowering cost of electricity at "off-peak" times, that the overall equation will shift.

> And truckers don't care about fuel density, they care about costs.

Costs come from a lot of places. Trucks sitting around charging instead of delivering goods are a cost. Reduced range means increased costs. Expensive batteries that have to be replaced every X years are a cost.

> Possibly, but as more renewable energy sources come online, the problem is going to change from "can we produce enough energy?" to "is the energy available at the right time and place?".

This is the most important point of the economics of renewables. Eg, I think Toyota was too early and applied to the wrong industry (personal vehicles), but not wrong.

For example, burning diesel for electricity (which is done a lot in remote areas and as backup) is really expensive, even just looking at the point of generation and not the externalities. If renewable electricity generation is hovering around the 2c per kWh mark, even with all the losses, H2 starts to make a lot of sense for a lot of energy intensive industries. Even more so when the electricity used to generate it was never going to get even sell for that price because it just wasn't needed.

Renewables have an economic problem currently where every solar panel and wind turbine added to an electricity network will have a lower ROI than previous ones due to their intermittent nature, lowering the return of older assets as well. As their use grows, this problem will get worse and generators will have this large earning potential with an asset generating wasted energy, with a life span measured in several decades. Long tail, lots of opportunity to do more with those assets.

Toyota is not wrong at all. Hydrogen is going to be the future of personal transportation too. EVs are basically unsustainable ideas as they require so much raw materials. Not to mention that we have to have hydrogen to hit zero emissions, but we don't need EVs at all.

I think the efficiency of pure EVs is too good to ignore. I'm not disagreeing that we have to have hydrogen to hit zero emissions, but lots of factors related to personal vehicles where pure EV makes sense. I don't think they will be the only types, possible over time as green hydrogen economics improve we might see more of a mix for sale.

But given how long it will take to build out to 3x renewable generation capacity and then auto makers to change, etc etc I don't think that will be for another 10+ years, but hope I'm wrong.

It's already starting to happen. It won't be something that happens decades in the future. The disruption of EVs by hydrogen technology is likely a current event.

I think its time we start realizing that much of the "efficiency" argument is an exaggeration or a lie. EVs aren't that efficient especially in cold weather, and fuel cell cars aren't really that far off. The other big issue is the inability to capture excess renewable energy. As we keep on building out more renewables, we're finding out that curtailed energy is growing exponentially. Pretty soon the vast majority of renewable energy will just go to waste. Hydrogen allows to use that energy, but batteries won't. Combined with the huge resource requirements of batteries it's clear that this technology is primed for a major stumble.