The Baltic nation of Estonia has launched an ambitious 100% renewable energy goal for 2030. As part of that goal, energy industry stakeholders plan to showcase the entire country as the world’s first nationwide, integrated “hydrogen valley” hub, with a focus on green hydrogen.
“Green Hydrogen” is made by using electricity to split water into hydrogen and oxygen. There’re no carbon emissions in that process, but to be truly “green” the electricity must come from a carbon free source like wind, solar, nuclear, or hydroelectric.
The process of electricity to hydrogen to compressed hydrogen to fuel cell to electricity is about half as energy efficient as electricity to li ion battery to electricity. As a form of electricity storage green hydrogen is significantly less efficient than batteries.
Green hydrogen only makes sense as a fuel in situations where batteries are not feasible.
And right now making green hydrogen at all does not make sense because if you build a new low carbon source of electricity it will make a larger impact if you use it to displace fossil fuel based electricity generation rather than using it to create green hydrogen.
What you wrote is essentially true of Li+ ion batteries (not truly green unless the electricity is too). The part I was missing was the efficiency of electrolysis being half that of Li+ charging.
Fuel cells can also run cars, and refilling is much faster than recharging. So you can build cars which can go long ranges with quick stops. But of course the infrastructure for hydrogen fuel is well behind even car chargers, let alone gasoline.
It’s usually faster, yeah. But honestly I’m not sure which I’d rather have in my cars, explosive Li batteries or explosive highly pressurized hydrogen. Or are we storing liquid hydrogen? Because that seems like an even worse idea.
It sucks that high density energy storage systems are by definition able to release a lot of energy (explosive).