Pumped-storage hydro dam schemes to store wind energy

[Eclipse]

All national parks and urban areas have been removed by the algorithm, although they have a heavy disclaimer.

None of the PHES sites discussed in this study have been the subject of geological, hydrological, environmental, heritage and other studies, and it is not known whether any particular site would be suitable. The commercial feasibility of developing these sites is unknown. As with all major engineering projects, diligent attention to quality assurance would be required for safety and efficacy.

There has been no investigation of land tenure apart from exclusion of some environmental areas and urban areas, and no discussions with land owners and managers. Nothing in this list of potential site locations implies any rights for development of these locations. Accuracy of the sites depends on the accuracy of the source data. There may be sites that fall into protected areas or urban areas that are not identified by the source data. In coastal regions there may be a few lower reservoirs sitting on top of the ocean due to limited accuracy of the DEM data.

But the overall message? The world has 100 TIMES the PHES sites it needs - pick your best, safest, least controversial, highest (most economical) 1% and you're done. If your state doesn't have it - build lines to it. It's there. This is a geological fact.

But that's the world.

Not the UK - the UK is fairly flat.

I'm not sure what percentage of this database's finds would be automatically ruled out - I imagine it would be quite high. (But national parks have already been mostly ruled out.)

STORAGE REQUIRED

An approximate guide to storage requirements for 100% renewable electricity, based on analysis for Australia, is 1 Gigawatt (GW) of power per million people with 20 hours of storage, which amounts to 20 GWh per million people [2]. This is for a strongly - connected large - area grid (1 million km2) with good wind and solar resources in a high energy use country. Local analysis is required for an individual country. For example, Australia needs about 500 GWh (and has storage potential that is 300 times larger) and the USA needs about 7000 GWh (and has storage potential that is 200 times larger)

For global pumped hydro ATLAS CLICK HERE

So I had a bit of a play with the Atlas database (above) and am by NO MEANS an expert! I'm not even sure what the different colours mean - I think I remember that gold is optimal (good head height) and red more expensive (less head height.) There's some engineering rule that if you TRIPLE the head, you HALVE the cost. I'll just have to take that on faith from the experts, as I have a Social Sciences background. (Just being honest.)

So we'll call the UK 68 Million people therefore 68 million * 20 GWh per million = 1360 GWh storage (or 1.36 TWh) required for the whole UK to have 20 hours storage per person.

I found 2250 GWh (2.25 TWh) just with the big 150 Gwh dam button selected.
There was 1 down south.



But the rest were all up north.


The next sample size was 50 GWH, which means we'd need about 28 - let's call it 30.
I found 60-ish such dams.

Here's North


Here's South


There were heaps more in the 15 GWH and 5 GWH categories but I ran out of links per post. Go play with the Atlas - it's fun.

But if there's a 90% fail rate on further investigation of these dams - then the UK would not have enough storage. The claim is not that each and every nation has 100 times more storage than it needs - although that's true most of the time. It's that each continent does! Each nation will have to decide what it is going to do within the geopolitics of its own unique situation. But that does not mean the potential PHES is not there. It is. Nations may just have to learn to 'get along'.

EG: Singapore doesn't have a hill above 15m - but it can import all the storage it wants from its neighbours.

[BritDownUnder]

I am in agreement with you on the UK needing more pumped storage. There is a good interview in Andrew Blakers I heard on the Energy Insiders podcast where he talks about his research and atlas of pumped storage in some depth.

I think all the high ground in England is national parks and if the government were serious they would allow some development of PHES to make this happen. Putting them all in Scotland would make little sense economically as power lines would need to be built to them whereas ones on the pumped storage on the Pennines would be closer to the demand and need shorter new transmission lines building to the National Grid. There's also the issue with Scots objecting to 'English' powerlines that already transport wind power to England and an undersea cable had to be built as a higher cost politically acceptable alternative. As an alternative to PHES using tidal pools in the Humber or Wash could also make sense as most of the excess power would be generated from North Sea offshore wind anyway and would make for shorter transmission lines.

For Scotland I can't understand why Loch Ness is not used as the lower reservoir due to its massive surface area and much lower elevation above sea level - only about 20 metres I think.

[Eclipse]

I will defer to local knowledge.

The Blakers interview was excellent. But how annoying are the dumb companies that are building PHES in Australia? The fact that just 50km down the road they could triple the head height and halve the cost - do these people have a clue as to what they're doing?

Blakers is emphatic that you use batteries for a few hours, and PHES for a few days. But here's the thing: I've never seen a table of comparative costs of different PHES builds on cost per kwh power delivered back to the grid, or even the capital cost per KWh capacity? Anyone seen anything like that?

[BritDownUnder]

I would say that each PHES scheme will be different so there can be no cookie cutter approach like there can be with wind turbines or batteries. The will have to be high consulting fees on each project especially for civil engineering. Anything that needs a tunnel seems to be a nightmare.

I can only think that a project 50km away that seems nicer just isn't. Whether it is a longer new transmission line required, more complicated geology, NIMBY action, land not available or just more complex civil works.

[Eclipse]

This article says the capital investment is about $100 per kwh capacity. I know some engineers like to talk about the capital expense - but I prefer the final price to the consumer.

https://theconversation.com/despite-the ... grid-68417

Professor Blakers has a spreadsheet you can tweak to see how it impacts the costs.
https://re100.eng.anu.edu.au/phescostmodel/index/

Note - I played with the head height in the green fields, but left the others as given. The head height is the difference between upper and lower reservoirs. Note how if you triple the head, it halves the cost! A 150m head is $82 MWh, and 700m is only $42 MWh. That extra gravity feeding the same amount of water through the same turbine station really does give the turbine room more power, cheaper.

[kenneal - lagger]

I think all the tidal impoundment schemes that I have seen had a degree of pumping involved in addition to natural refilling. Whether natural refilling was involved or additional pumping would depend on the state of the tide and the availability of excess generation elsewhere. There could also be the case of water being retained in the pond if there was excess power available.

[Eclipse]

There is zero natural refilling of off-river PHES - unless we're talking about rain?

[adam2]

A major new pumped storage scheme has been approved in Scotland. https://www.bbc.co.uk/news/uk-scotland- ... s-65015217

It remains to be seen if it will actually be built, or if "approved" simply means another round of reviews, plans, consultations, NIMBYfests and appeals.

[clv101]

It states power, 1.5GW, but not energy. When fully 'charged', how long can maintain 1.5GW?

[adam2]

They mention the ability to "power three million homes for up to 24 hours" Presuming the widely used figure of an average of 1 kw per home, then 3 million homes would be 3 million Kw, or 3 GW. or 72 GWH in total if 3 GW is maintained for 24 hours.
If they really do mean 72 GWH, then that is very impressive, but I suspect that some lower figure is correct.

Does anyone know reliably what the proposed storage capacity is ?

EDITED TO ADD THAT WE NOW KNOW THAT THE STORAGE CAPACITY IS 30 GWH. See following posts for details.

[BritDownUnder]

The SSE website says 30GWh.

[clv101]

Wow, that's significant. Similar to say 600,000 electric cars. Also a major asset for black starting the grid. Cost per GWh? Bet it's less than chemical batteries.

[adam2]

The SSE website says 30GWh.

Not as much as my estimate of 72 GWH, but still very impressive. Hope it gets built.

[adam2]

Wow, that's significant. Similar to say 600,000 electric cars. Also a major asset for black starting the grid. Cost per GWh? Bet it's less than chemical batteries.

Agreed, very valuable for black starting the grid, and for decreasing fossil fuel used. Cost is indeed almost certainly less than batteries, and with a longer working life.
The civil engineering works should last for centuries, and the other equipment for at least 50 years. 10 years is probably optimistic for batteries.
The main merit of battery storage is that they can be located near the load and thereby relieve inadequate transmission/distribution infrastructure.

Battery storage is not suitable for black starting the grid, the inverters used will not feed into a dead system. HVDC inter-connectors likewise wont supply power into a dead system.

[adam2]

Here is a more detailed report, which also confirms the 30 GWH of storage.
https://utilityweek.co.uk/inside-1bn-pu ... y-storage/