Vastly more efficient at storing electricity. Vastly more expensive to construct, using rare materials. Have a Vastly shorter lifespan than a hydrogen tank and much lower energy density. Everything is a compromise
Many batteries actually last significantly longer than common hydrogen storage tanks, hydrogen embrittlement is a major issue. Type III and IV tanks have a life cycle of 10 years. https://www.awoe.net/Hydrogen-Storage-LCA.html
Hydrogen has also terrible volumetric energy density. It’s also really heavy until you scale to huge tanks.
Hydrogen's volumetric energy density is about as good as lithium-ion. The cost of replacing a hydrogen tank vs a lithium battery is absolutely massive. You also aren't considering the energy density lost in cold weather for batteries.
Almost the same in the short term requires you to liquify hydrogen and then use it immediately. Because the energy density rapidly goes to zero for any application with a moderately sized tank. On top of which you need a cryogenic tank, costing you even more volume.
Liquifying hydrogen also costs you another ~10-13 kWh /kg where Hydrogen only contains 33kWh if you want heat, but more like 10-15kWh/kg if you want to do useful work. So you’re roughly paying double the energy for the same amount of energy stored.
How expensive, big, and heavy would a hydrogen tank (farm) be if it had to supply a whole winter for, say, 1million people.
I ask because one of the bigger transition issues I see in Europe is load shifting from summer surplus to winter deficits, specifically for heating.
Why would you want to store enough energy to supply for a whole winter? Wind energy delivers most power during the winter and even solar contributes a bit. The actual amounts to store would be a fraction of that. Of course, that might be the one single good use of hydrogen as a means of storage, but way less storage is needed than most would think.
