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.
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.
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.