Of course, no papers need to be published ... that may be the goal.
I think the more popular approach is to use a deep hole, like a mine shaft. Maybe depth measured in kms. Because you're suspending from above you might be able to get a bit heavier than 60 tons.
California is one potential location, and there's been a lot of interest in pumped hydro from the California Department of Energy (and utilities), but I doubt it'd work as well nationwide.
Checking their site, I see they currently have a 100MWh storage under construction in china, with a different, boxy-building design. No idea on costs. https://www.energyvault.com/project-cn-rudong
Good enough is good enough. There is no one size fits all, and we really need to start leveraging everything we can to tackle energy storage. Each thing used doesn't need to be perfect for energy density, it just has to be good enough.
> assume you build a tower 120 meters tall.
vs sticking a concrete block in the ground like this paper is proposing.
As long as the durability is there, and it scales up like they say, this concrete block thing has interesting practical potential, because concrete is so ubiquitous. It's in foundations, it's in walls, it's in floors, it's under the road, sidewalk etc.
Heck, where I live we could turn our whole street in to one big battery to service the neighbourhood, while we couldn't possibly stick a whopping great big tower with concrete blocks in it, or a suitable size water tower.
I have seen a few 120m towers. They call them skyscrappers.
Anyway, all this for 20Kwh. I can get a Nissan Leaf with a 40/60Kwh battery for way less than a skyscrapper. Most likely for way less than what it costs to make a 120m deep hole.
Long story short: cranes and concrete don't make a practical battery, but they make for many articles and publications.
Before you say "but lithium is hard to find, and concrete isn't": you can also make lead batteries, and ni/cd batteries, and liquid air batteries too. I don't expect the Earth to run out of air in the next decades.
Static concrete being able to store power like a battery, like the article is talking about, is ideal if it works (possibly with caveats depending on how quickly it degrades). It's a ubiquitous material, used all over the place. It'd be getting value out of something that is going to be used anyway.
Anything heavy can be used as a gravity battery. Water in hydro pump for example. Or lead, or concrete. Lead is not that cheap, concrete is not that effective. For water we usually have already constructed a dam, it's just a case of adding another pipe and a pump.
But I guarantee you that if we were to construct a dam, pipe and pump just for energy storage - instead of taking an already existing dam we built for another reason, it would also not be as good as a bunch of batteries in pretty much all relevant factors.
No, you can't replace all existing power sources now and into the future by pumped hydro.
Pumped hydro has a massive role to play in power supply, time shifting electricity from renewable sources, providing system resiliency, black start, inductive and inertial load, you-name-it. It also exists. It's in widespread use, across the globe. I have one less than 100km from me here in Qld, there is one under construction in the snowy hydro project (with issues) complementing an existing unit at Tumut, Another at Shoalhaven in NSW and there are two large sites in the UK power grid Dinorwig and Cruachan, both of which supply near-instantaneous (<20sec) power against demand shifts.
Compared to gas turbine load start (minutes), pumped hydro is fast (seconds). Compared to batteries (milliseconds), It's slow. Batteries have capacity limits too. In the capacity stakes, Pumped hydro can beat them hands-down but for a massive initial capital outlay. Snowy 2.0 will supply DAYS of power. 2Gigawatts, as 350GWh of power. 3 million homes equivalent, for a week. People argue about the economics, not about the underlying capability.
Worldwide there are plenty of good sites, including mine shafts. And, gravity models for power include trains, and cranes. Neither of which will replace all sources of power for all burdens in the network either. The idea this is limited to existing land-surface bodies of water simply isn't true.
Not all useful things have to be able to solve the problems "at the scale we need" to be both useful, and able to solve problems.
Imagine a giant empty bucket held high in the air. As it rains, the bucket fills and using a counter-weight it slowly lowers down to ground level. Now the bucket is covered and the water is slowly drained causing the counter-weight to lower to the ground and the bucket to rise in the air again.
If this were geared properly, could energy be generated in any meaningful amount?
Highest rainfall in a year:
> 26,470 mm (1,042 in); Cherrapunji, Meghalaya, India, 1860–1861
https://en.wikipedia.org/wiki/List_of_weather_records
26.4 tons * 1km * 9.8m/s/s / 1 year = 7.4 watts
Many people have done the math.
People in general demand quick, simple, easy and singular solutions to complex problems that cover massive ranges of financial, geographical, political, cultural, and individual variances with no tolerance, and they honestly believe they are being fair and reasonable when they do so.
Example:
Idea: "New houses could have cheap batteries built into their foundations, cheaply decreasing the load on the electrical grid and providing a backup source to cover temporary power outages."
Response: "Well, that's not going to completely solve the energy crisis, restore CO2 to pre-industrial revolution levels and avert the polar ice caps from melting, so what's the point?"
And they think that this response is rational.