Which is why we typically oversize the systems - to have excess production during the production hours which spreads out over non-production hours.
Which is why we're diversifying generation sources and developing storage systems with different runtime parameters.
That's politics. Engineering is what we should be talking about.
It's obvious that pumped hydro is a non-starter for the flat states like Kansas or North Dakota, but it doesn't mean that those states can't benefit from pumped hydro. At this time we have the preference for local generation (and storage) primarily due to high losses in the transmission lines. Most of our transmission lines are AC and are basically outdated by at least half a century. Replacing AC lines with HVDC lines solve quite a bit in that department.
I agree that storage systems will solve some of the issues but differ as to the practicality of being able to build as many as would be needed if solar and wind become major players in generation. From an economic point storage works better with solar than it does with wind as it is more predictable.
The first article in a recent post by another member uses a lot of phrases (emphasis added) like "possible
evolution of energy storage", "potential
coming wave of energy storage", "could
range from 130 gigawatts to 680 gigawatts in 2050". The second article takes a more detailed approach and analyzes the various storage methods for suitability in different uses. They determined that pumped hydro and compressed air were ill-suited for fast response situations and that flywheels and supercapacitors are not suitable for longer term applications. They found that batteries are the most likely to have the lowest projected Levelized Cost of Storage as stated here "Projected cost reductions for battery technologies limit the competitiveness of pumped hydro and compressed air. Battery technologies exhibit the highest probability of lowest LCOS in most applications beyond 2025. By 2030, lithium ion appears to be most cost efficient in most applications, in particular with <4 h discharge and <300 annual cycles such as power quality and black start."
It is an interesting read, although not a quick one. I am repeating the link so people won't have to search for it.
This study determines the lifetime cost of 9 electricity storage technologies in 12 power system applications from 2015 to 2050. We find that lithium-ion batteries are most cost effective beyond 2030, apart from in long discharge applications. The performance advantages of alternative...
One thing I find interesting is that in the graphical abstract comparing projections for 2030 and 2040 compressed air storage (CAES), green in the graphic, seems to completely disappear by 2040 and be replaced by hydrogen. They also show a significant percent of pumped hydro being replaced by lithium ion.