It’s very impressive for robust energy storage efficiency. 80% is awesome.
In the real world Li-ion is not optimally cycled, has a self-discharge rate that works out to around 10% loss a month even if it’s in a conditioned stable building envelope, needs a sophisticated battery management system that is not field maintainable, and requires periodic expensive replacement even in optimal conditions.
Hydrogen does not occur freely in nature; it has to be liberated from more complex materials, which requires energy input. It has pathetic energy density by unit volume, requiring more energy input to create safe storage, and over time it basically migrates through anything but metal (or even more costly materials) so all joints and seals have to be precision machined and matched to their vibration and temperature environments. Hydrogen total efficiency is abysmal in practice, even with modern fuel cells (that are generally extremely sensitive to membrane contamination and other costly failure modes); typically end-to-end efficiency of 20% in real world total analysis.
Meanwhile pumped storage has near-zero storage losses, low maintenance requirements for the impoundment, field-repairable pumps, turbines and generators, and if properly built can last hundreds of years. And it gets that awesome 80% efficiency you mentioned.
It’s misleading to compare laboratory efficiency numbers while eliding the differences in simplicity, maintainability and reliability. PHS, in the great many places where it’s possible, is better than batteries, and modern batteries are far better than hydrogen cycling. Hydrogen is a handout to petrochemical companies and other dirty energy producers masquerading as green tech.
Then you agree there is no good reason that solar installations without battery storage cannot power houses safely when the grid is down. It’s a completely solved problem.
I have no more time for this, sorry. Lots of high tech meatspace things to manage.
