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.
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.
The reservoirs in Finland aren't quite at the scale your Explorer Vodka-fuelled Swedish mind believe them to be. Most are small generators hooked up to the local rivers, and are required to prioritize keeping the water from flooding residential areas.
There's a reason we're looking at using old mines for pumped hydro rather than trying to pump water upriver during a spring flood because other power sources have surplus generation.
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.
> And pumped storage is significantly cheaper for seasonal storage than any proposed alternatives.
This is incorrect. There is currently not a single pumped hydro station that is suitable for seasonal storage. They're all designed to drain their upper reservoir in 4-16 hours.
It's the only thing that's half economical. Do the math: Even a modest power plant - 1 GW output - that can run for 1000 hours means you need a 1 TWh (even typing it feels ridiculous) storage reservoir. If you only have 100m of head, that's 3 cubic kilometers of water. That would mean building an artificial lake that immediately would be Norway's 6th largest body of fresh water, and draining it completely every winter.
And effectively, you'd have to build it twice - you also need a lower reservoir. Because there's nowhere to get 3 cubic kilometers of fresh water to fill it otherwise, and you really don't want to do pumped hydro with seawater.
Norway already have seasonal storage with a storage capacity equivalent to 6-8 months of total electricity use in the form of its existing hydroelectric plants, with no need to pump things back up again.
> And yet it's still far cheaper than any other form of seasonal storage.
Only for countries with very suitable landscape, and the willingness to use it - damming high altitude valley is extremely unpopular and bad for the environment.
Also, pumped hydro is expensive. Initial capex is higher than today's lithium batteries, if you design comparable systems. The only reason anybody is still building new pumped storage is that you can use it for 100 years (instead of 20 for the batteries, although nobody really knows how much they'll actually degrade).
I think we'll find hundreds of TWh of seasonal storage elsewhere. Thermal storage is extremely attractive if (or once) you have district heating installed. Takes care of a massive junk of domestic heating, and could take over light (food processing, paper,... ) and medium (chemical, ...) industry. Just don't try to turn it back into electricity...
Once steel and concrete get electrified, we might get seasonal hydrogen storage in underground salt caverns. Concrete and steel need absurd amounts of high heat which probably means making lots of hydrogen, putting those in the right locations might make additional hydrogen for fuel cells/gas turbines available, relatively cheaply (still extremely expensive, seasonal storage always is). But who knows...
> A typical pumped storage facility uses 100m of delta
Most projects seek 200-600m. This map doesn't even consider pumped hydro <200m: https://maps.nrel.gov/psh
> And pumped storage is significantly cheaper for seasonal storage than any proposed alternatives.
Based on what? Cost is particularly variable for pumped hydro. It can be one of the cheaper options when stars align. But you need 1) a suitable geography that minimizes the cost of damming or digging a resivoir with sufficient head 2) available for development without too much backlash 3) Near enough grid resources to minimize infrastructure and line losses. I'm surely leaving pieces out.
It can be cheap, but it has far more hoops to jump than alternatives like batteries, hot sand and other "storage-in-a-building" designs which can be built where needed and using fairly standard industrial construction.
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.
Looking at a few of them, a few obvious problems are apparent.
Firstly, it takes a rather liberal idea of how close the basins need to be to each other to be viable.
Secondly, most of the ones I looked at would require extensive relocation of existing populations and/or large-scale infrastructure changes, such as re-routing important roads.
The first few I looked at also do not have a sufficient water supply nearby - you'd face either covering them or you'd quickly run into problems of evaporation that you have little ability to replenish/replace.
A lot of the ones I quickly looked at would also face "fun" issues such as no nearby infrastructure such as roads to bring in construction materials.
I have no idea how many suitable locations there are on that map, but it seems pretty apparent it is a small fraction of the ones marked before you even consider how many would be politically unviable because of public resistance to the environmental destruction.
To be clear, I'm not at all opposed to investigating pumped storage, but it's also not nearly that simple.
The largest planned hydro storage projects are using decommissioned mines, and those are going to run out quickly.