New Large Scottish Pumped-Storage Hydroelectric Dams

[Peter Dow]

Scotland best for pumped-storage hydroelectricity energy economy

This is a statement of the obvious as far as Scottish electrical power-generation engineers and scientists are concerned I expect but I am making this statement anyway, not for the benefit of our scientists or engineers but to inform the political debate about the potential of the Scottish economy "after the North Sea oil runs out" because political debate involves mostly non-scientists and non-engineers who need to have such things explained to them.

The Scottish economy has a profitable living to make in future in the business of electrical energy import/export from/to English electrical power suppliers and perhaps even to countries further away one day.

The tried and tested engineering technology we Scots can use in future to make money is pumped-storage hydroelectricity.

Wikipedia: Pumped-storage hydroelectricity

The technique is currently the most cost-effective means of storing large amounts of electrical energy on an operating basis, but capital costs and the presence of appropriate geography are critical decision factors.

In Scotland, the Cruachan Dam pumped-storage hydroelectric power station was first operational in 1966 and was built there to take advantage of Scotland's appropriate geography and available capital.

So Scotland has the appropriate geography for pumped-storage hydroelectric power and we have the capital particularly if we invest some of the taxes on North Sea oil before it all runs out and it is all spent.

Investment in wind-power energy generation is proceeding apace, in Scotland, in England, on and offshore, and that's very "green" and quite clever, though wind power is not as dependable as tidal power, but unless and until sufficient capacity to store energy becomes available to supply needs when the wind isn't blowing then conventional, and perhaps increasingly expensive, coal, gas or oil burning or nuclear energy power will still be needed to keep the lights on when the wind doesn't blow.

Scottish opportunity
Here is the opportunity for the Scottish economy in a future where wind-power generation is increasingly rampant: if we Scots build a large capacity of new pumped-storage hydroelectric power stations, not only can we supply all our own Scottish energy needs from "green" renewable energy schemes, but we could provide energy storage capacity for customers outside Scotland, particularly in England, who live in a land not so well endowed with appropriate geography for hydroelectric power.

In future, a Scotland with investment in a massive pumped-storage hydroelectric capacity could buy cheap English wind-power while the wind is blowing then sell the same energy back to English power suppliers, at a profit, when the wind isn't blowing and the English will pay more for energy.

So everyone wins, the energy is all green, the electricity supply is always available when it is needed and that is how the Scottish energy economy does very well after the North Sea oil runs out. 

So problem solved but not job done as yet. We Scots do actually need to get busy investing and building pumped-storage hydroelectric power generation and supply capacity in Scotland now.

My vision for a LARGER hydro dam at Coire Glas than SSE propose

I am presenting here my vision for a large pumped storage hydroelectric 2-square kilometres surface-area reservoir and 300+ metre tall dam which I have designed for the Coire Glas site, Scotland.

(View site using Google Earth where the convenient label is "Loch a' Choire Ghlais" - or, http://tinyurl.com/coireglas)

I was inspired to conceive and to publish my vision by learning of the Scottish and Southern Energy (SSE) proposal to build a smaller hydroelectric pumped-storage scheme at Coire Glas which has been presented to the Scottish government for public consultation.

I have not long been aware of the SSE plan for the Coire Glas scheme, not being a follower of such matters routinely, but I was prompted by an earlier tangentially-related news story (about energy storage technology for renewable energy generators such as wind farms) to write to Members of the Scottish Parliament on the merits and urgency of new pumped storage hydroelectric power for Scotland on 14th February and a reply from Ian Anderson, the parliamentary manager for Dave Thomson MSP received the next day, the 15th February informed me about the SSE plan and Ian added "initially scoped at 600MW but, to quote SSE, could be bigger!"

I replied to Ian "So the schemes proposed by the SSE are welcome and ought to be green-lighted and fast-tracked, but I am really proposing that Scots start thinking long term about an order of magnitude and more greater investment in pumped storage hydroelectric capacity than those SSE plans."

So I had in mind "bigger would be better" but it was not until the next day on the 16th February when a news story informed me that the SSE plans had been submitted to the Scottish government for public consultation that I thought "this needs consideration now".

So starting late on the night of the 17th, early 18th February and all through the weekend, I got busy, outlining my alternative vision for a far bigger dam and reservoir at the same location.

So this is my vision as inspired by the SSE plan. If my vision is flawed then the fault is mine alone. If my vision is brilliant, then the brilliance too is mine.
 




Image also hosted on postimage

The black contour line at 550 metres elevation shows the outline of the SSE proposed reservoir of about 1 square kilometre surface-area and the grey thick line shows the position of the proposed SSE dam which would stand 92 metres tall and would be the tallest dam in Scotland and indeed Britain to date though it seems our dams are several times smaller than the tallest dams elsewhere in the world these days.

Part of the red contour line at 775 metres elevation, where the red line surrounds a blue shaded area, blue representing water, shows the outline of my larger reservoir of about 2 square kilometres surface-area and the thicker brown line shows the position of my proposed dam which would stand 317 metres tall which would be one of the tallest man-made dams in the world.

Enhanced satellite photograph




Image also hosted on PostImage.Org

Cross section of the Dow-dam
The Dow-dam would be more than 3 times higher than the proposed SSE-dam. In this diagram, a horizontal line one third of the way up the Dow-dam indicates the relative height of the SSE dam although it is not aligned with this cross-section.




Image also hosted on PostImage.Org

Maps showing the line of cross-section viewed from each side




Image also hosted on PostImage.Org




Image also hosted on PostImage.Org

Cross section of the Dow-dam reservoir



Cross section along the major diameter of the elliptical excavation of the reservoir bed


Also hosted on PostImage.org

Excavated Reservoir Bed

The green ellipse of major diameter of 1.5 kilometres and minor diameter of 1 kilometre represents an excavated reservoir bed, as flat and as horizontal as practical, at an elevation of 463 metres.

Since an excavated reservoir bed is not, that I can see, part of the SSE plan, at any size, I will provide some more information about my vision for that now.

The basic idea of excavating a flat or flattish reservoir bed is to increase the volume of the water stored in the reservoir because more water means more energy can be stored.

Depending on the geology and strength of the rock of Coire Glas the walls of the reservoir bed perimeter could be as steep as vertical from the reservoir bed up to the natural elevation of the existing rock surface which would mean, presumably, blasting out rock to create a cliff which at places could be as much as about 290 metres tall.

Near the dam, the reservoir bed perimeter wall would be only 40 metres or less tall. The further from the dam, the higher the wall will be and the more rock needs to be excavated.

A vertical reservoir bed perimeter wall would be ideal to maximise reservoir volume wherever the geology provides a strong stone which can maintain a vertical wall face without collapse, (a stone such as granite perhaps).

Where the geology only provides a weaker stone then a sloping perimeter wall at a suitable angle of repose for reliable stability would be constructed.

So the reservoir perimeter wall could be as sloped as shallow as 45 degrees from the natural elevation at the perimeter of the eclipse sloping down to the reservoir bed at 463 metres elevation in the case of the weakest and most prone to collapse kinds of stone.

Exactly how strong the stone is at each location I guess we'll only find out absolutely for sure if and when engineers start blasting it and testing the revealed rock wall face for strength.

The shape of the perimeter of the excavated reservoir bed is not absolutely critical. So long as it ends up as a stable wall or slope, however it is shaped by the blasting, it will be fine. There is no need to have stone masons chip the perimeter smooth and flat! The ellipse is simply the easiest approximate mathematical shape to describe and to draw. If the end result is not a perfect ellipse, don't worry, it will be fine!

OK, well I guess that's the vision part over. The rest is fairly straight-forward engineering I hope. Oh, and there is always getting the permission and the funding to build it of course which is never easy for anything this big.

OK, well if anyone has any questions or points to make about my vision or can say why they think the SSE plan is better than mine, or if you don't see why we need any pumped storage hydroelectric scheme at Coire Glas, whatever your point of view, if you have something to add in reply, please do.
 
Peter Dow

Scottish republican socialist, author and protester (Video profile)

Scottish National Standard Bearer website

[Peter Dow]

Loch Lochy and vicinity water flow control works

Here is an annotated satellite photograph of the land south from Coire Glas showing Loch Lochy, Loch Arkaig, the isthmus between the lochs, Mucomir where Loch Lochy empties into the River Spean before it flows on as the River Lochy, the Caledonian Canal and Fort William where the river flows into a sea loch.




Click to see larger image

New waterway

Loch Lochy is separated from a neighbouring loch, Loch Arkaig, by a 2 km wide isthmus, which I have identified on this map as "the Achnacarry Bunarkaig isthmus", after the local place names.

It ought to be quite straight forward to build a canal or culvert, to connect those two lochs. The idea is that the new waterway would be wide and deep enough, enough of a cross section area under water, perhaps hundreds of square metres, so as to allow free flow from one loch to the other, so as to equalise the surface elevations of the two lochs, so as to increase the effective surface area of Loch Lochy so as to decrease the depth changes to Loch Lochy when water flows in from the Coire Glas reservoir when it discharges water when supplying power.

Now, Loch Arkaig has a natural surface elevation of 43 metres and this would be lowered to that of Loch Lochy. The surface area of Loch Arkaig is given by wikipedia as 16 km^2 also, (though it looks to me somewhat smaller than Loch Lochy). In addition, partially draining Loch Arkaig to bring its level down to that of Loch Lochy will also reduce its surface area.

If say, the additional surface area of Loch Arkaig is about 10 km^2 added to Loch Lochy's 16 km^2 this would give an effective surface area of 26 km^2 and reduce the potential depth variation to

Potential depth variation of Loch Lochy + Loch Arkaig = 400 000 000 m^3 / 26 000 000 m^2 = 15.3 metres.

Without equalising the loch levels, the depth changes to Loch Lochy that would require to be managed may be potentially more like 25 metres than 15 metres. So the new waterway is an important part of the new water flow control works that Coire Glas/Dow requires to be constructed.

Additional Loch Lochy water level control measures

When the Coire Glas reservoir is full, then the water level of Loch Lochy should be prevented, by new water works - drains, dams, flood barriers etc. - from rising due to rainfall and natural flow into the loch above a safe level which allows for the reservoir to empty into the loch without overflowing and flooding.

The safe "upper-reservoir-full" loch level will likely turn out to be around about 15 metres below the maximum loch level.

The next diagram showing the new loch drain and the reservoir pump inlets indicates how this might be achieved.




Click to see larger image

The drain from Loch Lochy to the sea which goes underground from the 14 m elevation level in the loch would need capacity for the usual outflow from Loch Lochy which currently goes through the Mucomir hydroelectric station.

I have estimated the flow through Mucomir from its maximum power of 2MegaWatts and its head of 7m as somewhere near 0.2 Mega-cubic-metres-per-hour and compared that value using a spreadsheet I have written to predict the capacity of water flow through different sizes of drains using the empirical Manning formula and this is also useful for determining the appropriate size of the new water channel between the lochs.


Ease my quantity!

To construct Coire Glas/Dow/600GW.Hrs/12GW may cost of the order of around £20 billion, but that would be my order of magnitude educated guess more than a professional cost estimate.

In other words, I'm only really confident at this early "vision" stage that the cost would be closer to £20 billion than it would be to £2 billion or to £200 billion but I'm not claiming to be able to quote an accurate cost estimate at this stage.

I have not itemised my costs - how much for land, how much for labour, how much for trucks, how much for diggers, how much for cement, how much to install the generators etc. and the SSE have not published itemised costs for theirs either so I can't calculate my costs in a proportion to the SSE's costs.

Although my version offers 600 GigaWatt-Hours energy and 12 GigaWatts power (or 20 times the capacity and performance) some of the items in my version would cost more than "in proportion", in other words more than 20 times the SSE's cost.

For example, the cost of my dam will be more like 27 times the cost of the SSE's dam. (3.44 times higher and thicker and 2.27 times longer).

For example, the cost of excavating 400 million tonnes of rock from the reservoir bed to increase the capacity of the reservoir to hold water (and energy) in my version won't be in proportion to the SSE costs for excavating their reservoir bed because, as far as I know, they don't plan to excavate their reservoir bed at all.

On the other hand, my land costs are about the same as the SSE's - much less than in proportion. I may well need to use more land to dispose of the additional excavated rock spoil but perhaps when that additional land has been landscaped over it could be resold?

So it depends how much the land is as a proportion of the SSE's costs. If land is a small part of their costs, if 20 similar sites to build on are just as cheap and easy to buy then my costs will be much more than proportional, since saving land won't save much money.

If land is scarce and valuable and the cost to purchase suitable land with a good chance to get permission to build on it is a significant proportion of the SSE's or anyone's costs to build 20 of their size of hydro dam schemes then my costs may be better than proportional. Sometimes securing suitable land for development can be very problematic, very expensive. Sometimes people won't sell their land. Sometimes the authorities won't agree that the land can be used in this way.

The SSE say that suitable sites for such pumped storage schemes are rare indeed, so land costs may be very significant and my scheme good value for money.

If indeed the cost of my scheme is somewhere around £20 billion it is likely to cost far more than the SSE or any electrical power supply company looking to their annual profits for the next few years could possibly afford.

Something like £20 billion I expect could only be found as a national public infrastructure project, spending government money, like the building of a large bridge or motorway would be.

A £20 billion government project would require Treasury approval, at least while Scotland is ruled as part of the UK.

I have suggested funding my much larger hydro dam scheme by re-allocating of some of the Bank of England's "Quantitative Easing" funds which amount to some £300 billion of new money printed with not much to show for it.
.
 

[spuggie j]

That is one hell of a proposition! Workable and a nice way to plan for the future. Though the costing will be floating a there is no way to predict for inflation raw material costs etc on a project of this magnitude. If used to generate an exportable commodity as other options are depleted then it will pay for its self over time. Yet my main concern would be the infrastructure required to forward this. Considering the trouble and objections that appeared over the Beauly to Denny power lines then is ther not a chance of more? The highlands may have the raw materal for the power but its wilderness and remoteness can throw up more challenges thus forcing a cost increase. The construction of the rail network to the Highlands and the building of the Caladonian Canal are a good example. Ok they were 19c breakthroughs but even with modern methods it is one hell of a challenge.

[Haqa]

I have to say Peter, that although we have our differences on a lot of points, this one appears very well thought out and apparently workable. It could generate electricity for decades to come.


Nice one


H.

[shillelagh]

that is if they have the water to run it ...
http://www.bbc.co.uk/news/uk-17340844
yes i know its the south of england ... but didnt alex salmond offer them water .. shipping it down to the south if they didnt get the rainfall they need ....
 

[spuggie j]

Yes in a fasion but tied to HS2 extending to Scotland.

One question for Peter though "How will it affect the fishing?"

[Peter Dow]

That is one hell of a proposition! Workable and a nice way to plan for the future. Though the costing will be floating a there is no way to predict for inflation raw material costs etc on a project of this magnitude. If used to generate an exportable commodity as other options are depleted then it will pay for its self over time.

It would be one of the biggest projects Britain is doing, perhaps as big and expensive as the Sellafield nuclear site clean up, also costing about £20 billion.
 

 
 

World’s 10 Largest Construction Projects 
 
Sellafield Nuclear Site, England 
 
$30 billion 
 
Sellafield is the U.K.'s primary nuclear-fuel reprocessing facility. Located in Cumbria, 70 miles north of Liverpool, the plant covers 700 acres and employs 11,000 workers. Perhaps most notably, it is home to world's first commercial nuclear power plant, Calder Hall, which ended its 47 years of duty in 2003. In 2008, Nuclear Management Partners Ltd. (a consortium made up of Amec, URS and Areva) was hired to operate, clean up, and ultimately decommission Sellafield. The process will take more than a century. By 2120, the NDA expects the Sellafield site will have achieved brownfield status.

   
 
So $30 or £20 billion down the Sellafield nuclear drain and after one hundred years what will we Britons have to show for it? Nothing but a brown field site but that's progress compared to the hell that is Sellafield now!     
 
Whereas one hundred years after my hydro dam scheme was built it would still be providing clean, almost free energy to the people!     
 
Providing of course that no incompetent royalists get to wreck things meantime. I should remind people that I don't agree with the UK Constitution from Hell, the monarchy, the kingdom, and we'd do better as Britain, as Scotland, as England, as Wales and as Northern Ireland as republics for the nations.   
 

Yet my main concern would be the infrastructure required to forward this.

Oh what did you have in mind that's lacking?   
 

Considering the trouble and objections that appeared over the Beauly to Denny power lines then is ther not a chance of more?

There is a certainty of more Not-In-My-Back-Yard opposition. Not that such huge pylons tend to be sited in anyone's back yard unless their back yard is enormous!   
 
Pylons I think could do with an image makeover. I don't think children should be encouraged to climb them or fly kites near them but after all, the pylon is a good engineering design, a lot more stable than those wind turbine towers I bet. Be interesting to see who is standing tall after a major earthquake.   
 
Anyway to get back to more possible trouble and objections. I think those would melt away if there was a guarantee of government funding if there was approval for my scheme or for a similar project.   
 
Most people would think of all the jobs that would be directly and indirectly created by such a massive injection of cash.   
 

The highlands may have the raw materal for the power but its wilderness and remoteness can throw up more challenges thus forcing a cost increase.

 
Well as usual it is a lot easier for Muhammad to go the Mountain. Trying to build a massive 500 metre high water tower for 400 million cubic metres of water somewhere "more convenient" is a non-starter. And anyway, would you trust an artificially made 500 metre high water tower in your neighbourhood? I'd rather trust a mountain that has stood tall for millions of years!   


So you go to where the hill and water is and you build any missing bits of infrastructure that the project needs.   
 
 

The construction of the rail network to the Highlands and the building of the Caladonian Canal are a good example. Ok they were 19c breakthroughs but even with modern methods it is one hell of a challenge.

 
I think the biggest challenge is getting provisional Treasury approval for the funding of it. To even get it considered by the government as an infrastructure project they might be interested in backing is the biggest challenge.   


For example, the much promoted "Green bank" is only going to have a budget of £3 billion - and that's for everything - wind farms, tidal, wave - the whole renewable energy field.   
 
Meanwhile, the Bank of England splashing out with £325 billion of "Quantitative Easing" is getting no challenge at all from the government, politicians, media and the people.   
 
It is the same old story with the kingdom. If you are a "Sir" somebody, like Mervyn King, the kingdom will let you print £325 billion pounds worth of new money without a second thought.   
 
If however, you are a republican scientist with excellent ideas for the economy you are lucky if you are out of jail and got access to the internet - that's your lot, in a kingdom! 

[Peter Dow]

I have to say Peter, that although we have our differences on a lot of points, this one appears very well thought out and apparently workable. It could generate electricity for decades to come.


Nice one


H.

Thanks very much! 

[Peter Dow]

One question for Peter though "How will it affect the fishing?"

This is what the SSE say in their Non Technical Summary for their Coire Glas scheme -

13 FISH


13.1 Introduction


13.1.1 An assessment has been carried out to identify potential impacts on fish as a result of the
construction and operation of the Development.


13.1.2 The assessment has been informed through consultations with Scottish Environment
Protection Agency (SEPA), Scottish Natural Heritage (SNH), Lochaber District Salmon
Fisheries Board (LDSFB) and Lochaber and District Fisheries Trust (LDFT) regarding the type
and extent of fish surveys required. Within the vicinity of the Development, the finalised scope
of the fish survey work included a fish habitat survey, an electric fishing survey, a survey of the
littoral habitats in Loch a’ Choire Ghlais and a shoreline habitat survey of Loch Lochy.


13.2 Assessment Summary


13.2.1 The assessment concluded that potentially significant negative impacts during construction of
the Development would be limited to permanent habitat loss and fragmentation at Loch a'
Choire Ghlais and Allt a' Choire Ghlais from inundation of the area behind the dam, and
temporary deterioration of water quality in all waterbodies from construction activities. This is
likely to have a negative impact on trout habitat and a brown trout population within the area of
the proposed dam and reservoir.


13.2.2 Effective mitigation could be put in place to ensure pollution events are kept to a minimum to
avoid deterioration of water quality.


13.2.3 The assessment further concluded that no significant effects during operation of the
Development on fish are anticipated.

Now my proposed scheme for Coire Glas uses 20 times more water than the SSE's scheme and as a consequence the surface water level in Loch Lochy varies by about 15 metres in my scheme but nothing like that in the SSE's scheme.


So I suppose for my scheme, the likes of fishing boats, like all craft on Loch Lochy would need to have modified jetties, piers and marinas that had another 15 metres of depth of water for the boats to stay afloat "at low tide" so to speak.


Fish wouldn't have to swim up stream to get from Loch Lochy to Loch Arkaig as they do now so maybe that might mean more slow or lazy fish would end up in Loch Arkaig?


Aside from that, I think fishing would be much the same with my scheme as with the SSE's.

[spuggie j]

 Had to ask about the fish as I love trout fishing and it is an important pass time for many. A lot of dams and resevoirs both in use and disused have fisheries that are economically viable and do bring in income. That brings me to the scheme you propose. As the area that the proposal it is a beautiful wild and rugged outdoors area that outdoor activists enjoy which again brings in money. So a proposal that can cause minimal disruption and reduce "eyesores" avoids driving away the out door lovers and the income the bring. Fort William is an ideal base for these fishers and trekers.

 As for the fish not being able to migrate becoming lazy I am not sure they will. I have fished in fixed waters with no migation routes for the fish and you after a few years of acclimatisation get a fish that is bigger and fitter. They stay put and become the fish to catch. Many fish that become land locked adapt pretty quick and breed with no real impact on the survival of the fitest if anything it makes it harder but better. For some me included going fishing is as much the suroundings as well as catching a meal .

 As for the jetties that is not a problem in my view as extending them is easy enough. It would also mean that there is safe access for anglers at all times (weather permiting) to the site. Sometimes big projects as in both proposals can have benifits that can enjoyed by others and bring in extra income that might not be available otherwise.

[poppy]

I couldn't make out if there were any farms or homesteads of any kind in the area to be flooded, or in the possible flood area if it suffered a breach.
but apart from the naff name the dodgy video  the dam itself looks feasible

[Bruv]

No comment about Dams......but WELCOME BACK Poppy.

Nice to see you again.......

[spuggie j]

I couldn't make out if there were any farms or homesteads of any kind in the area to be flooded, or in the possible flood area if it suffered a breach.
but apart from the naff name the dodgy video  the dam itself looks feasible

The area is a wilderness in the terms of farming. The land is poor in the farming sense and you are more likely to run over a deer than a stray sheep. We have to think of the future before its too late. Besides to me the proposals appeal to me a lot more than wind farms. The one above Stirling may provide power but it is a carbuncle on the view over the hills and spoils the beauty of the area. To me the gain from hydro power is way ahead of the gain from wind power and has less of an impact enviromentally.

[poppy]

I couldn't make out if there were any farms or homesteads of any kind in the area to be flooded, or in the possible flood area if it suffered a breach.
but apart from the naff name the dodgy video  the dam itself looks feasible

The area is a wilderness in the terms of farming. The land is poor in the farming sense and you are more likely to run over a deer than a stray sheep. We have to think of the future before its too late. Besides to me the proposals appeal to me a lot more than wind farms. The one above Stirling may provide power but it is a carbuncle on the view over the hills and spoils the beauty of the area. To me the gain from hydro power is way ahead of the gain from wind power and has less of an impact enviromentally.

oh quite agree it looks like a very good project, was just curious because i couldn't see a single building, I have never seen such a huge space with nothing on it

[spuggie j]

Large parts of  Scotlands north is "empty" so to speak but the wildlife is plentyful and it is beautiful as well. The thing is projects like these could be used the same way that the USA used public financed projects during the 30's to give people jobs. Lower unemployment, taxes paid and a handy resource for the future. Alas though I am more likely to be the first man on Mars.