what about artificial hydro ? make a big large raised water retention thing with generators.. it will take space but not harm existing natural spaces. Even in europe there's a lot of unused land.
Pumped hydro needs to be truely massive scale, both in the amount of water (read: lots of depth AND surface area), and the height differential between the two reservoirs. To make it cost feasible we really need very favourable natural geography. Building such structures ourselves would be astronomically expensive.
Check the one near Cape Town. It can run for up to 12 hours with two "small" dams and the altitudes for the dams are ~100m & ~350m respectively, connected by water tunnels & 4 turbines. It is located in the mountains, right next to the coast (which I think minimizes negatives further).
The the size and rainfall season matters for how long they can run. Cape Town has a winter-rain season that runs from roughly May to September.
The capacity of the smaller of the two dams is 3,560 megalitres. I think a 1km X 350m X 10m deep is this capacity. So "small" is fairly subjective term, but you are right that it is not gargantuan. It is still not going to be easy to place such a setup just anywhere, but I'm willing to admit my statements may have been a little too much.
I would be interested in how much it cost to build and run to obtain the 180mwh capacity. A similarly size gridscale battery would cost in the vicinity of 40-60 million USD (using the $140 per kWh cost, numbers are is hard to find for the supporting equipment and installation costs).
There is probably an inflection point where pumped storage becomes more economical than batteries. With land and labour costs so different from lace to place what makes sense in certain areas, is probably not economical in others.
Pumped hydro does not, in fact, need "lots of depth". 10m is typical, for which cheap earthen dikes suffice.
It does not, in fact, need "very favourable natural geography". It needs an elevation difference, something found almost everywhere, Holland and Kansas excepted. Kansas has deep underground cavities, which also suffice.
Building dikes is cheap and low tech. Dikes predate written language.
On the depth thing, I really only meant to mean you need lots and lots of water. You could have a shallow basis, and take over a huge area of land, or or smaller amount of land if you have deeper water. Deeper also allows for less evaporation, less land area.
Perhaps your and my definitions of favourable geography are different. You need a water source, due to evaporation, you need a big resovoir at elevation, and another lower. If you don't want to build it all yourself you need valleys that you can close off at one end. You need ground that is not permeable, so the water you have stays where you want it.
Perhaps I am misreading you, but you seem a bit agitated with your in fact writing style. We're all friends here. I am not anti pumped storage. Far from it. If you can make it work economically, it's a great solution. It will definitely be part of the mix. But there's reasons it's not being rolled out everywhere, and a lot of this is due to cost and unfavorable geography.
You don't need a "huge area of land", under any circumstance. Even a football pitch is big enough for useful storage. Permeability is a thing that is controllable. Since there are so very many hills, only the most favorable sites need be considered.
The main reason it is not being rolled out much is that it is not time yet to roll it out. You need enough spare renewable generating capacity to charge it from, first, which we are very far from, most places. In the meantime the right place to spend is on generating capacity. Later, we will know better which storage methods are best.
I'm assuming you understand that my statements have a implicit "from an economic pov" when I argue about the practicality of pumped hydro storage, and you're arguing that it is economical to do pumped hydro on a small scale.
My understanding is that it only becomes competitive with other options at a very large scale. A 10 m deep football sized reservoir, at an altitude of 1km above the generator would have approx 13Mwh of energy storage at 100% efficiency (if my math is correct). Battery prices are around $140 per kWh, so a 13 Mwh battery installation is going to be in the vicinity of 2 million dollars.
I would love to see some costs involved in building two man made ten meter deep football field size dams, a large 1km length (it will be quite a lot longer due to it running on a slope) with all the required engineering to run it down a steep incline. The add to that the and generating equipment, and pumps.
Once you've done that, we could compare the operating costs of the two options.
Agreed, cost matters. While costs of the parts of a pumped hydro system are well-known, which of those parts need to be built for a given installation vary, as do their scale, but most importantly the costs of competing storage media, which are in many cases falling fast.
As for nukes, stable costs make them proportionally less competitive by the day, in the face of cheapening competition.
