Comment by Tuna-Fish
19 hours ago
We don't really. Hydro storage requires reservoirs where you can freely adjust the water level. Most of our lakes have shorelines that have been built out, and the property owners get really angry if you suggest frequently adjusting the water level significantly.
The largest planned hydro storage projects are using decommissioned mines, and those are going to run out quickly.
You could just build a back-channel for the existing hydro-dams? Those reservoirs are only full for a short period and that is when you dont need pump energy.
But where? In Finland, at least, the land is relatively flat when compared with Norway and Sweden, and with a large rural population there aren't really any good locations.
In my local area, we had major flooding this spring because the hydro plant operators were sleeping on the job (or whatever they did instead of regulating water levels). And that was a simple 2m increase in water levels.
NO/SE have some more geographically suitable locations, but last time I checked, flooding them was considered too environmentally destructive too the local environment.
Yeah, you're right regarding the environmental concerns.
Most of Norway's hydro dams were built a long time ago when there was little focus on the environmental effects.
The last major plant went live in 1993. Most of the focus now is on far smaller schemes, that doesn't really add up to a lot compared to Norway's established generating capacity (which outstrip the total electricity use anyway), but which also meet far less opposition.
Part of the reason for that was growing local opposition to larger plants, and sometimes national opposition, culminating with the Alta controversy[1] in the late 70's that were some of the largest civil protests in Norway since the end of WW2. The protests eventually failed, but it had a lasting effect on Norwegian politics.
[1] https://en.wikipedia.org/wiki/Alta_controversy
If you pump the water back into the existing reserviors you will have less flooding?
I suggested a pump-water extension to existing hydro power reservoirs.
Like your EV recharges when you release the pedal.
Right shouldn't talk about EVs with a Finn, that analogy will not fly. Ok, like if you plan carefully where you throw up your koskenkorva you can re-use it.
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You could use the ocean for the bottom level and an artificial reservoir for the top level. You're not going to noticeably affect ocean levels.
Or just use a large lake. You're not going to noticeably affect the water levels of a large lake. You might pump 10 billion litres of water, which is .02% of the volume of Mjøsa.
The problem is where to store it.
10 billion liters of water is 1,000 m^2 * 10m deep. There is no suitable location for that that is both elevated enough and near enough to Mjøsa to be financially viable.
Norway also existing hydro reservoirs with a capacity equivalent to around 6-8 months electricity supply, so it's not really a major need for Norway, anyway, but this is a fairly general problem: Finding suitable locations that are close enough to a water source, and provides a large enough potential reservoir is hard.
> Finding suitable locations ... is hard.
No it's not. Here's almost a million of them: https://re100.eng.anu.edu.au/global/
If big ones are hard, you can make a bunch of smaller ones.
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> You could use the ocean for the bottom level and an artificial reservoir for the top level. You're not going to noticeably affect ocean levels.
Then you have to deal with the problem of sea water corroding everything it touches.
> You might pump 10 billion litres of water, which is .02% of the volume of Mjøsa.
It's not the amount of water that you pump, it's the amount * the elevation delta. Where are you planning on getting the elevation delta from?
Neither of these challenges is technically insurmountable, but this is a field where capex + opex/KWH is everything.
> Where are you planning on getting the elevation delta from?
Elevation delta is not hard to find in Norway! A typical pumped storage facility uses 100m of delta; I imagine Norwegian ones would use more.
> but this is a field where capex + opex/KWH is everything.
And pumped storage is significantly cheaper for seasonal storage than any proposed alternatives.
The original post is efficient for heat storage, but converting low grade heat to electricity is not efficient.
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