70%-80% electrolysis efficiency is unbelievably terrible? There are many factors such as cost, time to market and availability. Batteries require lots of mining of materials and have a limited lifespan.
Fuel cells are only useful for automotive applications, on the grid you want combined cycle gas turbines which are cheaper and more efficient. That still only gets round trip efficiency to about 25%.
You are thinking of natural gas fueled turbines, you can also burn hydrogen in gas turbines. If that hydrogen was produced domestically via electrolysis using clean sources there isn’t any strategic issues.
Also, from a strategic perspective burning domestic natural gas and burning natural gas from a different country are very different things. Europe becoming dependent on Russian natural gas was stupid, but America burning it’s domestic natural gas is mostly just an environmental issue.
A fuel cell is a battery. It has the same fundamental efficiency as any other battery. Of course, this is not how it works in the real world, but people who cite "efficiency" are usually greatly exaggerating how it works. Most batteries cannot reach 95% efficiency, especially if they need to store energy for long periods of time. Round trip efficiency of hydrogen will beat any ICE doing the same thing, and with heat recapture will basically match a li-ion battery. In situations where li-ion is poorly suited, such as cold weather or long-term storage, hydrogen will often be more efficient.
How many cycles do those batteries work with that efficiency? How environmentally friendly is mining Lithium in China and transporting it around the globe? How much CO₂ does the transport of those minerals/batteries produce? How do we get rid of old batteries? One huge advantage of producing hydrogen or methane out of thin air with excess energy from truly renewable energy sources is, that we don't have to procure and transport source materials, and that it can be stored.
Lithium comes from a lot of places. The largest Lithium exporter in the world today is Australia. Multiple South American countries are also towards the top of the list.
A lot of lithium "mining" is digging up desert salt deposits or skimming salt brines from salt lakes. Some of that still isn't "perfectly" environmentally friendly, but compared to extracting most any other sort of mineral it is one of the environmentally friendliest we extract.
Lithium is the third element on the periodic table and the third most common element in the universe. Admittedly a lot of the planet's Lithium is in compounds/salts that sometimes need to be chemically broken down and that has more environmental impacts than the mining processes. So there is that, admittedly. But a lot of it is electrolytic just like the "advantageous" hydrogen processes people seem to love.
Lithium is not a rare or heavy mineral. It's the next fatter cousin of Hydrogen.
> How do we get rid of old batteries?
Recycling. Plenty of companies have already answered this question. Lithium is highly reclaimable from all existing Lithium-based battery formulations.
Producing and distributing hydrogen requires significant infrastructure that releases vastly more CO2 than moving lithium around for EV’s. I think you got blinded by thinking of hydrogen as green but it doesn’t magically show up.
Also, moving lithium around releases negligible CO2, an EV battery only needs 15 pounds of lithium and lasts 25 years. You can work out the exact number based on specific origin and destinations but it’s on the order of driving an ICE 1 to 10 miles. Which shouldn’t be surprising because boats are very efficient, lithium is light, and cars weigh a lot.
Wait till you hear about the efficiency of petrochemicals...
"In other words, even when the engine is operating at its point of maximum thermal efficiency, of the total heat energy released by the gasoline consumed, about 65-80% of total power is emitted as heat without being turned into useful work, i.e. turning the crankshaft."
Sure, but producing 1kWh worth of petrol doesn't require 1kWh of energy. Producing 1kWh worth of hydrogen through electrolysis always requires more than 1kWh of energy, it's just pure physics. Even if the process was 100% efficient through magic, it's still a stupid thing to rely on for producing hydrogen.
> producing 1kWh worth of petrol doesn't require 1kWh of energy
… so long as you don’t count the 1kWh of photosynthesis that was done by a bunch of ancient plankton to rip CO2 molecules apart and build hydrocarbons instead.
I meant the energy that was originally used to create oil in the first place. You don't need to add any more, because oil, unlike hydrogen, already exists.
