The rest of the world just builds a dam, creates a new lake, and moves on.
(Yes, if we used more hydro-electric then that would do the job for us, but it's not the case that we need this in order to store energy).
But your main point is correct. This has to store energy to control frequency.
This all becomes more complex when the loads are switch-mode power supplies and the generators are solar panels. The flywheel project adds some smoothing to the grid, as spinning generators are replaced with DC devices. But the principles are the same; without any extra devices, electricity has to be generated at the exact instant that it is consumed, and the consumers have a large physical effect on the generators.
(Frequency is not proportional to voltage in general, only in this spinning-generator connected to a spinning load case. You can obviously switch DC on and off at whatever frequency you desire, and a perfect on/off cycle consists of infinitely many frequencies at various amplitudes.)
https://www.wired.com/2016/05/forget-elons-batteries-fix-gri...
Flywheels contain tiny amount of energy, but can respond nearly instantaneously To provide frequency regulation on the grid.
Hydro has massive amounts of energy storage (days+ worth of output), but takes a looot longer to respond than flywheels.
I think we will see very little flywheel or dam construction in the coming decades; battery storage is becoming cheap enough that it will hit the non-linear inflection point in deployment in the next few years. First, lots of lithium ion, and likely after that lots of flow batteries.
Balmacaan and Coire Glas are in the planning stages and due to start building soon. There's plenty of high land available.
Your wording implies this is better than the flywheel solution - can you elaborate for a layman?
We have mountains (Wales, Lake District, Scotland), but the likelihood of creating lakes for hydro use is close to zero. And you would need many, many, flywheels to substitute for one lake.
Yes, because they'd be lochs, not lakes :-)
We already have some (e.g. https://en.wikipedia.org/wiki/Cruachan_Power_Station) and are talking about building more (https://www.bbc.co.uk/news/uk-scotland-highlands-islands-445...).
[1] https://www.google.com/maps/@50.514101,12.8731705,3067m/data...
[2] https://en.wikipedia.org/wiki/Markersbach_Pumped_Storage_Pow...
Or to put it another way, Britain has a long history of building water capacity for British cities.
Scandalous! /s
However, at least all the letters are familiar. Asian languages are at least an order of magnitude harder for westerners.
When I moved here, I arrogantly stated I was going to learn Irish. I'm humbled now.
https://wikitravel.org/en/Welsh_phrasebook
Or rather, the orthography is - spoken Welsh is ancient, but the way of writing it with Latin letters is relatively new, so it was worked out fairly sensibly.
The actual grammar is headache-inducing, though.
In case anyone's wondering what this is about, in the 1960s the Tryweryn Valley in Wales contained a village (Capel Celyn) which was evacuated and the valley flooded to make a new reservoir to provide water for Liverpool. There's a portion of a nearby wall painted with these words.
UK is an island, and you have highlands. Why not make some salt water lakes there?
We're the size of Michigan with 67 million people.