Pumped hydro is always brought up, which is bizarre to me because it's highly dependent on your geography, unlike battery storage.
To flip that around, there exist applications where battery storage isn't reasonable. Is it thus also bizarre to bring batteries?
You're not answering:
> To flip that around, there exist applications where battery storage isn't reasonable. Is it thus also bizarre to bring batteries?
The post I was replying to called talking about hydro storage "bizarre". I was pointing out that it isn't. The logic here seems analogous to saying that compact cars suck because you can't use them as a dump truck.
The strong part of pumped hydropower is that it scales really really well even if the baseline efficiency isn't stellar.
https://www.google.com/maps/@43.9207263,-86.3978435,18314m/d...
It's a big power station, 1.8 GW, but is only providing service to portion of consumers in Michigan.
Making it 10 times bigger would probably be doable but it wouldn't be trivial.
It's also one of the better places on the planet to build a single reservoir system (otherwise you need 2 enormous reservoirs).
I wonder if the answer to seasonal variation will be to make fuel in the summer.
It kind of reminds me of people that think that we should use the exercise bikes in gyms to power the lighting; yes, brilliant, but actually run the numbers and you realize that humans output very very little energy even at peak exercise. The amount of waste on generators would be phenomenal.
There are some cases where pumped hydro makes sense, but there's limited scalability.
I'm sure compressed air in other forms would be a good store. You could also raise and lower weights into a mine, it doesn't matter so long as you can convert between electric energy and kinetic potential of some kind.
1000L tank on a roof which is ~4m high.
E = m * g * h = 1000 * 9.8 * 4 = ~40,000J
Which is about 12Wh not taking into account any losses.
You could maybe improve this by having the water fall into a well but still nowhere near what a battery can provide for a fraction of the cost/complexity.
A standard 100Ah battery will provide 1200Wh.
For example, 1000 kilograms of water (1 cubic meter) at the top of a 100 meter tower has a potential energy of about 0.272 kW·h (capable of raising the temperature of the same amount of water by only 0.23 Celsius = 0.42 Fahrenheit).
https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit...
Given the much smaller height of a rooftop tank, every 1000 kg of water pumped would support a number of minutes of normal household usage (a decent refrigerator would need several thousand kg per hour).