3 ms·

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

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.

vkou 11mo ago
> 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.
- bryanlarsen 11mo ago
  > 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.
  - skybrian 11mo ago
    For some applications, you don't actually convert the heat to electricity. This sounds pretty cheap if it works out: https://austinvernon.site/blog/standardthermal.html https://austinvernon.site/blog/standardthermal.html
  - kmacdough 11mo ago
    > 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 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.
  - pbmonster 11mo ago
    > 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.
    - bryanlarsen 11mo ago
      And yet it's still far cheaper than any other form of seasonal storage. Seasonal storage is crazy expensive. You need a lot of power, and a lot of energy, but you can only amortize the cost over one or two usages per year.
      - vidarh 11mo ago
        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.
      - pbmonster 11mo ago
        > 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...
vidarh 11mo ago
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.
- deleted 11mo ago
  [deleted]
- bryanlarsen 11mo ago
  > Finding suitable locations ... is hard. No it's not. Here's almost a million of them: https://re100.eng.anu.edu.au/global/ https://re100.eng.anu.edu.au/global/ If big ones are hard, you can make a bunch of smaller ones.
  - vidarh 11mo ago
    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.

vkou 11mo ago

> 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.

bryanlarsen 11mo ago
> 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.
- skybrian 11mo ago
  For some applications, you don't actually convert the heat to electricity. This sounds pretty cheap if it works out: https://austinvernon.site/blog/standardthermal.html https://austinvernon.site/blog/standardthermal.html
- kmacdough 11mo ago
  > 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 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.
- pbmonster 11mo ago
  > 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.
  - bryanlarsen 11mo ago
    And yet it's still far cheaper than any other form of seasonal storage. Seasonal storage is crazy expensive. You need a lot of power, and a lot of energy, but you can only amortize the cost over one or two usages per year.
    - vidarh 11mo ago
      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.
    - pbmonster 11mo ago
      > 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...

vidarh 11mo ago

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.

deleted 11mo ago
[deleted]
bryanlarsen 11mo ago
> Finding suitable locations ... is hard. No it's not. Here's almost a million of them: https://re100.eng.anu.edu.au/global/ https://re100.eng.anu.edu.au/global/ If big ones are hard, you can make a bunch of smaller ones.
- vidarh 11mo ago
  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.