[adrianN]

The efficiency numbers for e-fuels are simple too bad. Fuel cells might maybe be made to work, but there is no Hydrogen infrastructure available.

Any e-fuel that can use normal petrol infrastructure and is burnt in an ICE has absolutely atrocious efficiency. Not only do you lose a large fraction of the energy going from electricity to fuel, but then you burn it in an engine that has 40% efficiency is a lab and 15% efficiency in city traffic. It just makes no sense outside of niche applications.

[Skyy93]

There is also no comprehensive infrastructure for charging your e-car everyhwere, at least in Germany. Also if all cars would be replaced into e-cars we simply do not have enough juice. So there has to be a infrastructure development no matter what way you choose.

You also have charging losses which electric cars, they are just not that high as with e-fuels. E-fuels have the advantage of being easily transportable and refuel is done in 1-3 minutes. So why not create them in countries that have much sun (free and endless energy) and convert this into something useful.

[adrianN]

> So why not create them in countries that have much sun (free and endless energy) and convert this into something useful.

Because that's not economical. It's cheaper to ship in the electricity directly, or if you don't want to build the HVDC lines (there are good reasons for that), turn it into Hydrogen, ship that and turn it back into electricity. Electrolysis is reasonably efficient (>70%), and the round trip to electricity can be done at 40% efficiency or so. Charge an EV with that elecricity and you're still much better off than first turning the electricity to Diesel (<30% efficienct) and then burning the Diesel (<<40%).

And that's not even taking into account all the health benefits of not burning stuff where people want to breathe.

[Skyy93]

If you just argue economical we should continue to burn fossile energy, because its pretty cheap. In smaller countries the amount of space for solar panels and sufficient amount of wind is not given. Not if you also want to produce food in your country. So there you need an alternative and hydrogen that comes from country with nearly unlimited energy and much space is inevitable.

[adrianN]

Fossil fuels are not cheap if you properly price in the externality of causing global warming (and other pollution).

You don't need a lot of space for wind and solar. Take Germany for example. Using just the area currently used for "energy crops" (around 2.4 million hectares) for PV you could cover most of the primary(!) energy demand of the country. Wind is even more space efficient in Germany.

[Skyy93]

E-cars and other technology have also "hidden" costs, your cobalt does not grow on trees.

Yeah perfect idea using farmland that could be used for growing food wasting on PVs. Do not get me wrong, there has something to happen but perhaps only solar and wind will not safe us as long as we have no good battery technology. Therefore it would be better to store this in some fuel.

[adrianN]

Oil doesn't grow on trees either, remember the oil spills we have regularly?

We already use that farmland to grow fuel instead of food, and we also have the technology to store the energy: electrolysis. But because that is relatively expensive you don't want to burn that fuel in shitty tiny generators, you want to burn it in efficient combined-cycle plants.