95% stored energy by what measurement? See my other comment. It is not accessible to everyone, nor can it be made accessible to everyone, and the current storage capacity is a marginal fraction of what we actually use. It's a short term load balancing tool that operates within a small energy window.
kenhwang|3 years ago
There's little to no water use in the storage or discharge of pumped hydro, water goes from one reservoir into another. The limiting factor is how much water can be pumped/discharged, not how much water is available in storage (which tends to be significantly more than the amount pumped around). So there's little reason why they wouldn't currently be fully utilized.
It's true that it requires specific geography (water and a place to put water), but it turns out population centers tend to be developed near water sources, already store water for the sake of storing water, and water can feasibly be stored in large quantities underground as well. Which means there's practically many viable large capacity sites near the places that use electricity.
cupofpython|3 years ago
Pumped storage is great at what it does, no denying that. And what it does is allow energy production to remain near average while demand varies, and consequently allows energy production levels to be adjusted a bit slower. You aren't addressing the raw numbers though. It serves best as a compliment to a continuous energy production system. As an actual battery/storage solution, it is weak. So it will not be the solution used to store a massive amount of energy generated over a short period of time in order to be used over a longer period of time.
I agree they should be fully utilized, but I am trying to explain that if you fully utilize pumped storage you are still going to have an incomplete energy storage problem. Of course the water levels dont get near max or min capacity - it is designed to take out exactly what you put in as soon as possible or else there is too much risk. The raw storage capacity is small to medium sized - about 10 hours at max discharge (and max discharge might not be enough to keep up with demand entirely on its own).
Basically, the more energy you need to draw the faster you need to drain it and the more energy you want to store, the more massive your reservoir needs to be.
These things cannot be made 100 to 1000 times bigger, nor is there capacity to make 100 to 1000 times more of them. We are better off having them vs not having them but it isnt enough, and if we find a better solution it may become obsolete