The Anonymous Widower

Drax Submits Application To Expand Iconic ‘Hollow Mountain’ Power Station

The title of this post, is the same as that of this press release from Drax.

The project is called Cruachan 2 and is described on this web site.

This is the introduction to the project.

We have kickstarted the planning process to build a new underground pumped hydro storage power station – more than doubling the electricity generating capacity at Cruachan.

The 600 megawatt (MW) power station will be located inside Ben Cruachan – Argyll’s highest mountain – and increase the site’s total capacity to 1 gigawatt (GW).

The new power station would be built within a new, hollowed-out cavern which would be large enough to fit Big Ben on its side, to the east of Drax’s existing 440MW pumped storage hydro station. More than a million tonnes of rock would be excavated to create the cavern and other parts of the power station. The existing upper reservoir, which can hold 2.4 billion gallons of water, has the capacity to serve both power stations.

Note.

  1. The generation capacity will be increased from 440 MW to 1040 MW, which is an increase of 36 %.
  2. Cruachan has a storage capacity of 7.1 GWh, which will not be increased.
  3. Cruachan opened in October 1965, so the generating equipment is nearly sixty years old.

I will assume that Drax and its various previous owners have kept the turbines, generators, dam and associated pipework in good condition, but as an Electrical Engineer, I do believe that the modern equipment, that will be used in Cruachan 2 will offer advantages.

  • One of these advantages could be the ability to ramp up power faster, than the original equipment.
  • I also suspect, it will have a sophisticated computer control system, that will allow the output of the power station to be precisely controlled.

These two features should mean that when a spike in power demand happens, that the combined Cruachan will step up to the plate.

So all those watching the Celtic and Rangers match on television, will still get their half-time cuppa.

I suspect that the combined Cruachan will be a power regulator of the highest quality.

Will The Storage Capacity Of Drax Be Increased?

Drax don’t appear to have any plans for increasing the size of the upper reservoir and I suspect that geography can’t deliver an affordable solution.

But.

  • Loch Awe is an excellent lower reservoir for a pumped storage system.
  • The building of Cruachan 2 may create substantial employment and economic benefits in the area.
  • Cruachan 2 is not the only pumped storage scheme under development in the area.
  • The UK needs as much pumped energy storage as can be created.

I wouldn’t be surprised to see, further development of Cruachan, if Cruachan 2 is an overwhelming success.

It’ll all be down to the geography and the economics.

 

May 17, 2022 Posted by | Energy, Energy Storage | , , | 1 Comment

Ofgem Enables National Grid To Make Early Payment Of Interconnector Revenues, Helping To Reduce Household Bills

The title of this post, is the same as that of this press release from National Grid.

These are the first three paragraphs.

National Grid has offered to pay £200m of interconnector revenues ahead of schedule rather than at the end of the standard five-year review period to play its part in reducing household energy bills.

Interconnectors, which are subsea electricity cables connecting the UK and Europe, enable the import of cheaper, cleaner energy from European neighbours, supporting security of supply and reducing carbon emissions.

It’s estimated that National Grid’s interconnector portfolio will help the UK avoid around 100 million tonnes of carbon emissions by 2030.

Ofgem has approved National Grid’s request to make early payments.

These are my thoughts.

What’s In It For Consumers?

National Grid is making a payment early, so they are not getting anything, they won’t eventually get.

But they are getting it early!

What’s In It For National Grid?

As National Grid is making a payment early, they are forgoing interest on the £200 million.

In New Electricity ‘Superhighways’ Needed To Cope With Surge In Wind Power, I talked about National Grid’s plan to build new North-South interconnectors, that would handle all the extra wind-power.

National Grid currently owns all or part of these operating or planned interconnectors.

National Grid would appear to have a substantial interest in the UK’s interconnectors and is the £200 million payment to ensure they get the contract to build and operate any new UK interconnectors? I’m not saying it’s a bribe, but it’s just operating the interconnectors in a manner that is an advantage to the UK and its electricity customers.

Surely, if the ultimate customers are happy, there will be less calls for the break-up of National Grid.

What Is A Cap And Floor Regime?

The press release explains a cap and floor regime like this.

Ofgem’s cap and floor regime sets a yearly maximum (cap) and minimum (floor) level for the revenues that the interconnector licensees can earn over a 25-year period. Usually, revenues generated by the interconnector are compared against the cap and floor levels over five-year periods. Top-up payments are made to the interconnector licensee if revenues are lower than the floor; and similarly, the licensee pays revenues in excess of the cap to consumers.

Ofgem’s approval enables National Grid to make payments of above cap revenues significantly earlier than originally planned, which will contribute to reducing consumer energy costs over the next two years. National Grid is now working with Ofgem to explore how to ensure the early payments can have the most impact for consumers.

I wonder if Ofgem and National Grid feel that a cap and floor regime is not only good for them, but for electricity consumers as well.

Cap And Floor Regimes And Energy Storage

There has been talk that cap and floor regimes should be used for energy storage.

This article on Current News is entitled Cap And Floor Mechanism The ‘Standout Solution’ For Long Duration Storage, KPMG Finds.

These are the first two paragraphs.

A cap and floor regime would be the most beneficial solution for supporting long duration energy storage, a KPMG report has found.

Commissioned by Drax, the report detailed how there is currently no appropriate investment mechanism for long duration storage. Examining four investment mechanisms – the Contracts for Difference (CfD) scheme, Regulated Asset Value (RAV) model, cap and floor regime and a reformed Capacity Market – it identified cap and floor as the best solution.

I also suspect that if the operator does a National Grid with the revenues, a cap and floor regime, must be even better.

I would not be surprised to see schemes like Coire Glas pumped hydro operating under a cap and floor regime.

Effect On Other Energy Companies

Wind farms seem to be operated under the Contracts for Difference scheme in many cases, but will we see cap and floor regimes being used in this market?

I can certainly see a new regime emerging, that is better for investors, wind farm builders, consumers and the Treasury.

In some ways keeping a happy relationship between the investors, Government and consumers is most important. So as National Grid, the Government and consumers don’t seem to be jumping up and down about their cap-and-floor regime, it must be working reasonably well!

Conclusion

Get the right regime and quality investors could be flocking to the UK’s energy generation and supply industry.

National Grid by their actions in paying up early, have thoroughly endorsed the system.

May 12, 2022 Posted by | Energy, Energy Storage | , , , , | 9 Comments

Ministerial Roundtable Seeks To Unlock Investment In UK Energy Storage

The title of this post, is the same as that of this press release from Drax.

These are the first two paragraphs.

Business leaders have met with UK Energy Minister the Rt Hon Greg Hands MP to discuss how the government could unlock significant investment in vital energy storage technologies needed to decarbonise the power sector and help ensure greater energy independence.

The meeting was organised by the Long-Duration Electricity Storage Alliance, a new association of companies, progressing plans across a range of technologies to be first of their kind to be developed in the UK for decades.

This press release, which I found on the Drax website, has obviously been produced by the four companies; Drax, Highview Power, Invinity Energy Systems and SSE Renewables.

Greg Hands MP, who is the Minister of State for Business, Energy and Clean Growth said this.

The Long-Duration Electricity Storage Alliance is a key part of our plan to get the full benefit from our world-class renewables sector. Government have already committed £68 million of funding toward the development of these technologies.

“This will support the UK as we shift towards domestically-produced renewable energy that will boost our energy security and create jobs and investment.

The three CEOs and a director from SSE, make statements about what they are doing and what they need from Government, which are all worth reading.

  • Drax still needs planning permission for its flagship project at Cruachan, that is called Cruachan 2.
  • SSE are saying that the massive 30 GWh Coire Glas pumped hydro scheme has full planning permission and is shovel-ready.
  • Drax and SSE appear to be in favour of Cap and Floor regimes to support long term energy storage.
  • Highview Power and Invinity Energy Systems appear very optimistic.
  • Finance for capital cost is not mentioned. As billions will be needed for some of these schemes and the returns are very predictable, I assume that it has been promised.

After reading this press release fully, I too am optimistic.

Conclusion

I feel sure, that a sensible plan will evolve fairly soon, which will involve these four companies and possibly some others.

March 19, 2022 Posted by | Energy, Energy Storage | , , , , , , | 5 Comments

Scotland’s Energy Storage

I have been using the web sites of Drax Group, SSE Renewables and ILI Group, and this page from Strathclyde University to look at various hydro-electric schemes to store energy using the tried-and-tested method of pumped hydro.

I have analysed these schemes.

Affric/Beauly

The scheme is now owned by SSE Renewables and has a page on their web site, which introduces the scheme like this.

Situated about 16 kilometres to the west of Inverness, Beauly is the gateway to the Affric/Beauly hydro electric scheme.

Currently, it generates a maximum power of 100.3 MW.

My analysis in Repurposing The Affric/Beauly Hydro-Electric Scheme, showed the following.

  • Research from Strathclyde University, says that the Affric/Beauly scheme could support 78 GWh of pumped storage in one scheme at Fasnakyle.
  • Adding pumped storage facilities to the Affric/Beauly hydro-electric scheme, with a capacity of upwards of a conservative 50 GWh, should be possible.

Generating capacity and system operation could be improved by replacing some or all of the 1950s and 1960s turbines with modern units and using modern control systems.

The Affric/Beauly hydro-electric scheme could be augmented by upwards of 50 GWh of storage.

Balliemeanoch

This new scheme is being developed by the ILI Group.

From what is published in the press. it appears to be a giant 1.5 GW/45 GWh project.

In Thoughts On The Balliemeanoch Pumped-Hydro Scheme, I analyse the plan.

The Balliemeanoch hydro-electric scheme could add 45 GWh of storage.

Balmacaan

This new scheme is being developed by SSE Renewables.

My searches in A Possible Balmacaan Pumped Storage System, showed the following.

It has a 600 MW generating capacity and I suspect would have about 15-20 GWh of storage.

The Balmacaan hydro-electric scheme could conservatively add upwards of 15 GWh of storage.

Breadalbane

The scheme is now owned by SSE Renewables and has a page on their web site, which introduces the scheme like this.

The Breadalbane scheme is set in the mountainous region around Loch Lyon, Loch Tay and Loch Earn in Perthshire.

Currently, it generates a maximum power of 168.4 MW.

My analysis in Repurposing The Breadalbane Hydro-Electric Scheme, showed the following.

  • Research from Strathclyde University, says that the Breadalbane scheme could support 12 GWh of pumped storage in one scheme at Ben Lawers.
  • I believe a similar scheme could be built South of Loch Tay to add a similar amount of pumped storage capacity.

As with the Beauly/Affric scheme, generating capacity and system operation could be improved by replacing some or all of the 1950s and 1960s turbines with modern units and using modern control systems.

The Breadalbane hydro-electric scheme could be augmented by upwards of 12 GWh of storage.

Coire Glass

This new scheme is being developed by SSE Renewables and the project has its own web site, which introduces the scheme like this.

Coire Glas is a hydro pumped storage scheme with a potential capacity of up to 1500MW. Coire Glas is an excellent pumped storage site with a large lower reservoir (Loch Lochy) and a significant elevation of more than 500m between the lower and the new upper reservoir site over a relatively short distance.

It is planned to generate a maximum power of up to 1.5 GW for twenty hours, which indicates an energy storage capacity of 30 GWh.

In SSE Renewables Launches 1.5GW Coire Glas Construction Tender, I talk about the current status of the project.

The Coire Glas hydro-electric scheme could add 30 GWh of storage.

Conon

The scheme is now owned by SSE Renewables and has a page on their web site, which introduces the scheme like this.

The Conon scheme lies within the northwest Highlands, broadly between Inverness and Ullapool. Electricity generation started here when the Ross-shire Electricity Supply Company built the small Falls of Conon hydro electric power station in the 1920s.

Currently, it generates a maximum power of 107.2 MW.

My analysis in Repurposing The Conon Hydro-Electric Scheme, showed the following.

  • Research from Strathclyde University, says that the Conon scheme could support up to 131 GWh of pumped storage.
  • Adding pumped storage facilities to the Conon hydro-electric scheme, with a capacity of upwards of a conservative 30-40 GWh, should be possible.

As with other schemes, generating capacity and system operation could be improved by replacing some or all of the 1950s turbines with modern units and using modern control systems.

The Conon hydro-electric scheme could be augmented by upwards of 30 GWh of storage.

Corrievarkie

This new scheme is being developed by the ILI Group.

From the planning application it appears to be a 600 MW/14.5 GWh project.

In Corrievarkie Pumped Storage Hydro Project, I analyse the plan.

The Corrievarkie hydro-electric scheme could add 14.5 GWh of storage.

Cruachan

Cruachan is a pumped-storage power station, that is owned by Drax, which have a comprehensive web site for the power station.

  • It has an output of 440 MW.
  • It has an energy storage capacity of 7.1 GWh
  • It can can reach full generating capacity in less than 30 seconds.

In Drax’s Plans For Cruachan, I analyse Drax’s plans, which they call Cruachan 2.

  • It will be a 600 MW power station.
  • It will be to the East of the current power station.
  • More than a million tonnes of rock would be excavated to build the power station.

The existing upper reservoir, which can hold 2.4 billion gallons of water, has the capacity to serve both power stations.

These was my conclusions.

It looks like very good engineering to me.

  • There is a good chance, that on most nights, the reservoir will be filled using wind energy
  • The maximum output of the Cruachan power station has been more than tripled from 323 to 1010 MW.
  • There has been no increase in the size of the Cruachan reservoir.

Scotland will now have a GW-sized hydro-electric power station.

It will not be very much smaller than Sizewell B nuclear station.

Foyers

The scheme is now owned by SSE Renewables and has a page on their web site, which introduces the scheme like this.

The current Foyers Power Station operates quite differently to conventional hydro electric power stations. Foyers hydro scheme consists of one pumped hydro power station and one hydro power station and one major dam..

Currently, it generates a maximum power of 305 MW.

My research and analysis in The Development Of The Foyers Pumped Storage Scheme, showed the following.

  • Foyers is a modern pumped-hydro scheme with a capacity of 10 GWh.
  • The updating of the original 1896 hydro-power station to a modern pumped-storage system in 1974 is a superb example of hydro-power engineering.

The development of Foyers power station is an example, that shows what can be done in other hydro-electric schemes around Scotland and the rest of the world.

Galloway

Galloway is a hydroelectric scheme, that is owned by Drax, which have a comprehensive web site for their two hydroelectric schemes in Scotland; Galloway and Lanark.

  • Galloway has a total output of 109 MW.
  • It has six power stations at Drumjohn, Kendoon, Carsfad, Earlstoun, Glenlee and Tongland.
  • There is no energy storage
  • It is what is known as a run-of-the-river scheme.

The scheme opened in the 1930s.

Glendoe

The scheme is now owned by SSE Renewables and has a page on their web site, which introduces the scheme like this.

In 2009, the first major hydro electric power station to be built in Scotland for almost 30 years, Glendoe on the eastern shore of Loch Ness, began generating electricity.

Currently, it generates a maximum power of 106.5 MW.

My analysis in Glendoe Hydro Power Station, led me to conclude, that engineers will look at this scheme built in the early years of this century to convert it to a pumped storage facility. It might even have been designed for conversion to a pumped storage station, as it was built after the successful conversion of Foyers power station. Comparing the size of the upper lake to Foyers and other schemes, I would estimate it could easily provide in excess of 15 GWh of storage.

The Glendoe hydro-electric scheme could be augmented by upwards of 15 GWh of storage.

Glenmuckloch

This is a small scheme promoted by Buccleuch, that generates 4 MW and stores 1.6 GWh in a disused opencast coal mine.

My analysis in The Glenmuckloch Pumped Storage Scheme, led me to this conclusion.

This project appears to have stalled, but I do like the idea of using a disused mine to store energy and the engineering behind the project.

I will ignore it in my conclusions of this post.

Great Glen

The scheme is now owned by SSE Renewables and has a page on their web site, which introduces the scheme like this.

The Great Glen runs for more than 100 kilometres from Inverness in the northeast, to Fort William in the southwest, following a geological fault line that divides north and south Scotland.

Currently, it generates a maximum power of 112.7 MW.

My analysis in Repurposing The Great Glen Hydro-Electric Scheme, showed the following.

  • Research from Strathclyde University, says that the Great Glen scheme could support up to 90 GWh of pumped storage.
  • Adding pumped storage facilities to the Great Glen hydro-electric scheme, with a capacity of upwards of a conservative 30 GWh, should be possible.

As with other schemes, generating capacity and system operation could be improved by replacing some or all of the 1950s and 1960s turbines with modern units and using modern control systems.

The Great Glen hydro-electric scheme could be augmented by upwards of 30 GWh of storage.

Lanark

Lanark is a hydroelectric scheme, that is owned by Drax, which have a comprehensive web site for their two hydroelectric schemes in Scotland; Galloway and Lanark.

  • Lanark has a total output of 17 MW.
  • It has two power stations at Bonnington and Stonebyres.
  • There is no energy storage
  • It is what is known as a run-of-the-river scheme.

The scheme opened in the 1920s.

Red John

This new scheme is being developed by ILI Group and the project has its own web site, which introduces the scheme like this.

Between 2007 and 2015, the total installed capacity of renewables electricity in Scotland has more than doubled. Due to its intermittent nature, the rise in renewable generation has resulted in increased demand for flexible capacity to help meet energy balancing requirements for the national grid system.

Pumped storage hydro is considered by the Directors to be the most developed and largest capacity form of grid energy storage that currently exists. This can help reduce renewable energy curtailment and therefore promote grid stability.

The web site says this about the project.

  • The scheme has an output of 450 MW.
  • The storage capacity is 2.8 GWh.
  • The scheme has planning consent.
  • The project is budgeted to cost £550 million.
  • The construction program indicates that the scheme will be completed by the end of 2025.

It also has very detailed maps.

I wrote about the project in Red John Pumped Storage Hydro Project, where I came to these conclusions.

  • This scheme has the output of a large gas-fired power station for just over six hours.
  • The finances must add up, as no-one would back a scheme like this if they didn’t get an adequate return on their money.

It may only be a small scheme, that is a quarter of the size of the existing nearby Foyers pumped-storage scheme, but as it is shovel-ready, we should start digging.

The Red John hydro-electric scheme would add 2.8 GWh of storage.

Shin

The scheme is now owned by SSE Renewables and has a page on their web site, which introduces the scheme like this.

Shin is Scotland’s most northerly hydro electric scheme. It utilises water from a 650 square kilometre catchment area in Sutherland, including Loch Shin, and water from the River Cassley and River Brora.

Currently, it generates a maximum power of 32.1 MW.

My analysis in Shin Hydro Power Scheme, showed the following.

  • I would be very surprised if any pumped storage were to be added to this scheme.
  • This 1950s scheme has been partially updated.

Perhaps some more updating would be worthwhile.

Sloy/Awe

The scheme is now owned by SSE Renewables and has a page on their web site, which introduces the scheme like this.

With the exception of Cruachan Power Station which was commissioned in 1965, major work on the Sloy/Awe scheme was completed by 1963, the year the Beatles had their first No 1 hit with From Me To You – and a world away from the immediate post-war austerity being experienced when Sloy Power Station was commissioned just 14 years earlier.

Currently, it generates a maximum power of 261.9 MW.

My analysis in Repurposing The Sloy/Awe Hydro-Electric Scheme, showed the following.

  • Research from Strathclyde University, says that the Sloy/Awe scheme could support up to 68 GWh of pumped storage.
  • Adding pumped storage facilities to the Sloy/Awe hydro-electric scheme, with a capacity of upwards of a conservative 40 GWh, should be possible.

As with other schemes, generating capacity and system operation could be improved by replacing some or all of the 1930s and 1950s turbines with modern units and using modern control systems.

The Sloy/Awe hydro-electric scheme could be augmented by upwards of 40 GWh of storage.

Tummel Valley

The scheme is now owned by SSE Renewables and has a page on their web site, which introduces the scheme like this.

The Tummel scheme stretches from Dalwhinnie, famous for its whisky distillery, in the north, to the remote Rannoch Station in the west, and the highly-popular tourist town of Pitlochry in the east.

Currently, it generates a maximum power of 309.2 MW.

My analysis in Repurposing The Tummel Hydro-Electric Scheme, showed the following.

  • Research from Strathclyde University, says that the Tummel Valley scheme could support up to 135 GWh of pumped storage.
  • Adding pumped storage facilities to the Tummel Valley hydro-electric scheme, with a capacity of upwards of a conservative 40-60 GWh, should be possible.

As with other schemes, generating capacity and system operation could be improved by replacing some or all of the 1930s and 1950s turbines with modern units and using modern control systems.

The Tummel Valley hydro-electric scheme could be augmented by upwards of 40 GWh of storage.

A Simple Summary

These are deliberately conservative figures from my analysis.

  • Affric/Beauly – 50 GWh
  • Balliemeanoch – 45 GWh
  • Balmacaan – 15 GWh
  • Breadalbane – 12 GWh
  • Coire Glas – 30 GWh
  • Conon – 30 GWh
  • Corrievarkie – 14.5 GWh
  • Glendoe – 15 GWh
  • Great Glen – 30 GWh
  • Red John – 2.8 GWh
  • Sloy/Awe – 40 GWh
  • Tummel Valley – 40 GWh

Note.

  1. With new storage like Balliemeanoch, Balmacaan, Coire Glas, Corrievarkie and Red John, I am using published figures where they are available.
  2. With figures from existing schemes,I am being deliberately very conservative.

That is a total of 324.3 GWh with 107.3 GWh down to new storage

Strathclyde University’s Prediction

This page on the Strathclyde University web site, gives these figures for the possible amounts of pumped-storage that can be added to existing schemes.

  • Errochty – 16
  • Glasgarnock – 23
  • Luichart – 38
  • Clunie – 40
  • Fannich – 70
  • Rannoch – 41
  • Fasnakyle – 78
  • Tummel – 38
  • Ben Lawers – 12
  • Nant – 48
  • Invermoriston – 22
  • Invergarry – 41
  • Quoich – 27
  • Sloy – 20

That is a total of 514 GWh or 621.3 GWh if you include new storage.

Conclusion

Scotland and the UK, has been left a superb legacy for the future by the pioneering work of Scottish engineers and the North of Scotland Hydroelectric Board.

Most of these assets are now in the hands of two groups; Scottish and Southern Energy (SSE) and Drax Group.

Having seen several of the schemes detailed in this post, in the last few weeks, on Michael Portillo’s; Great Coastal Railway Journeys, it does seem that both groups are looking after their assets.

SSE and Drax also seem to be doing their best to publicise the success of one of the UK’s high-value, but low-profile engineering assets.

I believe that we should do a survey that would identify the following.

  • What needs to be done to allow each aqueduct, dam, power station and tunnel to continue to function until a given date in the future.
  • Which of the individual schemes can be updated to larger schemes or pumped storage systems.

We would then be able to device a long term plan to create a world-class hydro-electric power scheme for Scotland.

Scotland should be able to provide upwards of 400 GWh of pumped-storage.

This article on Current News is entitled Up To 24GW Of Long Duration Storage Needed For 2035 Net Zero Electricity System – Aurora.

These are the first three paragraphs.

Deploying large quantities of long duration electricity storage (LDES) could reduce system costs and reliance on gas, but greater policy support is needed to enable this, Aurora Energy Research has found.

In a new report, Aurora detailed how up to 24GW of LDES – defined as that with a duration of four hours or above – could be needed to effectively manage the intermittency of renewable generation in line with goals of operating a net zero electricity system by 2035. This is equivalent to eight times the current installed capacity.

Additionally, introducing large quantities of LDES in the UK could reduce system costs by £1.13 billion a year in 2035, cutting household bills by £26 – a hot topic with energy bills on the rise as a result of high wholesale power prices.

The report also says that long duration storage could cut carbon emissions by ten million tonnes of carbon dioxide per year.

It appears to me, Scotland can provide more than enough energy storage for the UK and the Island of Ireland, even if the seas around the British Isles were almost completed covered by wind turbines.

In addition, to the works in Scotland to update the various hydroelectric schemes, there would need to be more interconnectors around the UK and probably to close countries like Belgium, Denmark, France, Germany, the Netherlands and Norway.

There could even be an interconnector between Iceland and Scotland, so Iceland’s abundance of zero-carbon electricity could be exported to Europe.

 

 

 

March 2, 2022 Posted by | Energy, Energy Storage | , , , , , , , , , , , , | Leave a comment

Repurposing The Sloy/Awe Hydro Scheme

The Sloy/Awe hydro-electric scheme was built in the 1930s and 1950s, by the North of Scotland Hydroelectric Board.

  • The scheme is now owned by SSE Renewables and has a page on their web site.
  • There are ten individual power stations; Sloy, Sron Mor, Clachan, Allt-na-Lairige, Nant, Inverawe, Inverawe, Loch Gair, Striven and Lussa.
  • There are four dams; Sloy, Allt-na-Lairige and two dams at Shira.
  • Cruachan used to be part of this scheme, but is now owned by Drax.

This map from the SSE Renewables web site shows the layout of the dams and power stations.

The sizes of the power stations in the scheme are as follows.

  • Sloy – 152.5 MW
  • Sron Mor – 5 MW
  • Clachan – 40 MW
  • Allt-na-Lairige – 6 MW
  • Nant – 15 MW
  • Inverawe – 25 MW
  • Kilmelford – 2 MW
  • Loch Gair – 6 MW
  • Striven – 8 MW
  • Lussa – 2.4 MW

This gives a total power of 261.9 MW.

It should be noted that Cruachan power station is also in this area and in Drax’s Plans For Cruachan, I talked about expanding the station from a 440 MW/7.1 GWh pumped-storage station to one of 1040 MW/7.1 GWh.

Scotland would appear to have 1.3 GW of hydro-electric power between Loch Awe and Loch Lomond.

 

This Google Map shows the same area as the SSE Renewables Map.

Note.

  1. Loch Awe, which is the sixth biggest freshwater loch in Scotland, is in the North-East corner.
  2. Loch Fyne, which is the longest sea loch in Scotland, is in the South-West corner.
  3. Loch Lomond, which is the second biggest freshwater loch in Scotland, is in the South-East corner.
  4. Loch Long reaches up from the South to the West of Loch Lomond.

These are four big lochs.

Strathclyde University And Pumped Storage Power For Scotland

This page on the Strathclyde University gives a list of the pumped storage potential for Scottish hydrogen-electric dams and power stations.

These figures are given for the dams and lochs in the Sloy/Awe scheme.

  • Sloy – 20 GWh
  • Nant – 48 GWh

It would appear that based on research from Strathclyde University, that the Sloy/Awe scheme could support over 60 GWh of pumped storage.

Water Flows In The Sloy/Awe Scheme

Looking at the SSE Renewables map of the Sloy/Awe scheme, water flows appear to be as follows.

  • Loch Awe to Loch Etive via Inverawe power station.
  • Cruachan reservoir to Loch Awe via Cruachan power station.
  • Loch Nant to  Loch Awe via Nant power station.
  • Loch Nant to Loch Etive via Inverawe power station.
  • Lochan Shira to Lochan Sron Mor via Sron Mor power station.
  • Lochan Sron Mor to Loch Fyne via Clachan power station.
  • Allt-na-Lairige reservoir to Loch Fyne via Allt-na-Lairige power station.
  • Loch Sloy to Loch Lomond via Sloy power station.

All the water eventually flows into the sea to the West from Loch Etive and Loch Fyne.

Refurbishing And Repurposing The Sloy/Awe Scheme

Perhaps as the power stations are now over fifty years old, one simple way to increase the generating capacity of the Sloy/Awe scheme, might be to selectively replace the turbines, with modern turbines, that can generate electricity more efficiently.

I suspect that SSE Renewables have an ongoing program of improvements and replacements for all of their hydro-electric stations in Scotland. Some turbines at Sloy power station have already been replaced with larger ones.

Adding Pumped Storage To The Sloy/Awe Scheme

Strathclyde University picked out two places where pumped storage could be added; Sloy and Nant.

I discussed Sloy power station in A Lower-Cost Pumped Hydro Storage System and came to these conclusions.

  • For £40 million, 14 GWh of pumped storage can be created at Sloy.
  • But it could be bigger than 14 GWh, as this page on the Strathclyde University web site, says 20.4 GWh is possible.
  • This would surely, be a project that could be first in the queue, once the environmental problems are solved.

20 GWh or even 14 GWh of pumped storage would be nice to have reasonably quickly.

As I said, this must be a high priority project.

The other project is at Loch Nant.

Note.

  1. Loch Nant is in the Western side of the map.
  2. Nant power station is marked by the red arrow.
  3. The loch to the South of the power station is Loch Awe.
  4. It appears that water can also go from Loch Nant to Inverawe power station to the North-East of the loch.
  5. Inverawe power station is on Loch Awe, which curves round Loch Nant.
  6. The 440MW/7.1 GWh Cruachan pumped-storage power station is on the other side of Loch Awe in the North East corner of the map, with the Cruachan dam and reservoir above.

Strathclyde University says that 48 MWh of pumped-storage could be possible at Loch Nant.

  • Comparing the size of Cruchan reservoir at 7.1 GWh and the larger Loch Nant, gives me hope that Loch Nant could hold upwards of 20-30 GWh.
  • From pictures on this page at Subterranea Britannica, it appears Nant power station has only a single 15 MW turbo-generator.
  • Inverawe power station is a 25 MW power station with a single turbo-generator.

I suspect that pump-turbines could be installed to fill Loch Nant from Loch Awe, just as was done at Foyers, where a 300 MW pumped storage power station was created.

Conclusion

There would appear to be up to two schemes, that could  each add around 20 GWh of pumped storage.

One advantage is that the waters of Loch Awe and Loch Lomond can be used for the lower reservoir.

 

March 1, 2022 Posted by | Energy, Energy Storage | , , , , , , , , , , , , | 1 Comment

A Brief History Of Scottish Hydropower

The title of this post, is the same as that of this page on the Drax Group web site.

This is the introductory paragraph.

Over the last century, Scottish hydro power has played a major part in the country’s energy make up. While today it might trail behind wind, solar and biomass as a source of renewable electricity in Great Britain, it played a vital role in connecting vast swathes of rural Scotland to the power grid – some of which had no electricity as late as the 1960s. And all by making use of two plentiful Scottish resources: water and mountains.

These are some points from the page.

  • The first scheme was built in the last years of the nineteenth century and provided power for aluminium smelting.
  • The first modern scheme was the Lanark Hydro Electric Scheme, which was built in the 1920s and is still running today, under the ownership of Drax Group.
  • In 1935, the Galloway scheme, set the tone for later projects with architecture including stylised dams and modernist turbine halls.
  • The North of Scotland Hydroelectric Board was founded in 1943.
  • Sloy, the largest conventional hydro-electric station opened in 1950 and has a capacity of 152.5 MW.
  • Building the dams and power stations appears to have been hard but well-paid work.
  • By the mid Sixties, the North of Scotland Hydroelectric Board had built 54 main power stations and 78 dams. Northern Scotland was now 90% connected to the national grid.
  • In 1965, the world’s then largest reversible pumped storage power station opened at Cruachan.
  • In 2009, the last major scheme at Glendoe opened.

The schemes are a working catalogue of everything you can do with water to generate and store electricity.

Future development now seems to be moving in two directions.

The Drax page says this about new hydro-electric schemes.

In recent years, however, the real growth has been in smaller hydro-electric schemes that may power just one or a handful of properties – with more than 100 MW of such generation capacity installed in the Highlands since 2006.

On the other hand, several large pumped storage schemes are under development.

Note.

These schemes add up to an output of just over 4 GW and a colossal 92.3 GWh of storage.

The existing Foyers scheme and the under-development Coire Glas and Red John schemes. all use Loch Ness as the lower reservoir.

Two of these under-development schemes will be larger than the current largest pumped storage system in the world; Bath County Pumped Storage Station in Virginia in the United States, which is a 3 GW/24 GWh system.

Conclusion

Adding large numbers of wind turbines and tens of GWs to Scotland’s existing pumped storage could transform not just Scotland’s but most of Western Europe’s green energy production.

 

February 14, 2022 Posted by | Energy, Energy Storage | , , , , , , , , | 11 Comments

New Electricity ‘Superhighways’ Needed To Cope With Surge In Wind Power

The title of this post, is the same as that of this article on the Telegraph.

This is the first two paragraphs.

Energy companies are pushing for the rapid approval of new electricity “superhighways” between Scotland and England amid fears that a lack of capacity will set back the country’s wind power revolution.

Businesses including SSE and Scottish Power are calling on the industry regulator Ofgem to approve a series of major new north-south power cables in a bid to ease congestion on the existing electricity network.

These points are mentioned in the article.

  • Current capacity is 6 GW, which even now is not enough.
  • Another 17 GW of capacity will be needed by 2033.
  • Wind farms in Scotland have been switched off and replaced by gas-fired power stations because of a lack of grid capacity.
  • Another 25 GW of wind farms could be built after leases were awarded last month.

Two North-South interconnectors are being planned.

Peterhead And Drax

This is being proposed by SSE and National Grid.

  • It will be an undersea cable.
  • It will be two cables, each with a capacity of 2 GW.
  • Peterhead and Drax power station are four hundred miles apart by road and 279 miles as the seagull flies, as a lot of the route would be over the sea. So an undersea connection would appear to be sensible.
  • Peterhead is on the coast, so connecting an undersea interconnector shouldn’t be too challenging or disruptive to the locals.
  • Drax power station is a 4 GW power station and the largest in the UK, so it must have good grid connections.

This Google Map shows the location of Drax power station in relation to Hull, Scunthorpe and the rivers in the area.

Note.

  1. Drax is marked by the red arrow in the West of the map.
  2. The large body of water in the East is the Humber Estuary.
  3. Hull is on the North Bank of the Humber.
  4. Scunthorpe, which is famous for its steel industry is South of the Humber in the middle of the map.
  5. To the West of Scunthorpe the Humber splits into the Trent and the Ouse.
  6. The Ouse leads all the way to Drax power station.

I suspect an undersea cable could go up the Humber and Ouse to Drax power station.

Is it a coincidence that both Drax power station and the proposed link to Peterhead are both around 4 GW?

Consider.

  • Drax is a biomass power station, so it is not a zero carbon power station.
  • Drax produces around six percent of the UK’s electricity.
  • Most of the biomass comes by ship from North America.
  • Protest groups regularly have protests at Drax because of its carbon emissions.
  • Drax Group are experimenting with carbon capture.
  • Drax is a big site and a large energy storage system could be built there.
  • Wind is often criticised by opponents, saying wind is useless when the wind doesn’t blow.
  • The Scots would be unlikely to send power to England, if they were short.

This is also said about Drax in Wikipedia.

Despite this intent for baseload operation, it was designed with a reasonable ability for load-following, being able to ramp up or down by 5% of full power per minute within the range of 50–100% of full power.

I take this it means it can be used to top up electricity generation to meet demand. Add in energy storage and it could be a superb load-follower.

So could the similar size of the interconnector and Drax power station be deliberate to guarantee England a 4 GW feed at all states of the wind?

I don’t think it is a coincidence.

Torness And Hawthorn Pit And Torness and South Humberside

These two cables are being proposed by Scottish Power.

  • Each will be two GW.
  • Torness is the site of the 1.36 GW Torness nuclear power station, which is likely to be decommissioned before 2030.
  • Torness will have good grid connections and it is close to the sea.
  • Hawthorn Pit is a large closed coal mine to the North of Newcastle, with a large substation close to the site. I suspect it will be an ideal place to feed power into the grid for Newcastle and it is close to the sea.
  • Just South of Hawthorn Pit are the 1.32 GW Hartlepool nuclear power station, which will be decommissioned in 2024 and the landfall of the cables to the massive Dogger Bank wind farm.
  • As I showed earlier with Drax, the Humber would be an ideal estuary to bring underwater power cables into the surrounding area. So perhaps the cable will go to Scunthorpe for the steelworks.
  • As at Drax, there is backup in South Humberside, but here it is from the two Keadby gas-fired power stations.

The article in the Telegraph only gives the briefest of details of Scottish Power’s plans, but I suspect, that given the locations of the ends of the interconnectors, I suspect the cables will be underwater.

Conclusion

It strikes me that all three interconnectors have been well thought thought and they serve a variety of objectives.

  • Bring Scottish wind power, South to England.
  • Connect wind farms to the two nuclear power station sites at Hartlepool and Torness, that will close at the end of the decade.
  • Allow the big 4 GW biomass-fired station at Drax to back up wind farms and step in when needed.
  • Cut carbon emissions at Drax.
  • Use underwater cables as much as possible to transfer the power, to avoid the disruption of digging in underground cables.

It looks to be a good plan.

February 13, 2022 Posted by | Energy | , , , , , , , , , , , , , | 8 Comments

Cap And Floor Mechanism The ‘Standout Solution’ For Long Duration Storage, KPMG Finds

The title of this post, is the same as that of this article on Current News.

These are the first two paragraphs.

A cap and floor regime would be the most beneficial solution for supporting long duration energy storage, a KPMG report has found.

Commissioned by Drax, the report detailed how there is currently no appropriate investment mechanism for long duration storage. Examining four investment mechanisms – the Contracts for Difference (CfD) scheme, Regulated Asset Value (RAV) model, cap and floor regime and a reformed Capacity Market – it identified cap and floor as the best solution.

Cap and floor has been used successfully in the financing of interconnectors, so perhaps to apply it to long duration energy storage, will lead to greater use of such storage.

January 12, 2022 Posted by | Energy Storage, Finance | , , , , | Leave a comment

Drax’s Plans For Cruachan

Cruachan Power Station is a pumped-storage hydroelectric power station in Argyll and Bute, Scotland.

  • It can generate 440 MW of power.
  • It has a storage capacity of 7.1 GWh.
  • The power station is owned by Drax.

This Google Map shows the area around the power station.

Note.

  1. Cruachan Reservoir is the upper reservoir for the power station.
  2. The River Awe is the lower reservoir.
  3. The turbines for the power station are in a hollowed-out Ben Cruachan.
  4. There is a visitor centre, which is two-hundred metres from the Falls of Cruachan station, that can be seen on the map, by the river.

More information on visiting can be found at the Visit Cruachan web site.

This second map shows the Southern part of the  Cruachan Reservoir to a larger scale.

Note the strength of the dam.

The Operation Of Cruachan Power Station

Wikipedia says this about the operation of Cruachan power station.

The station is capable of generating 440 megawatts (590,000 hp) of electricity from four turbines, two of 100 megawatts (130,000 hp) and two of 120 megawatts (160,000 hp) capacity, after two units were upgraded in 2005. It can go from standby to full production in two minutes, or thirty seconds if compressed air is used to start the turbines spinning. When the top reservoir is full, Cruachan can operate for 22 hours before the supply of water is exhausted. At full power, the turbines can pump at 167 cubic metres (5,900 cu ft) per second and generate at 200 cubic metres (7,100 cu ft) per second.

What I find surprising, is that they only upgraded two turbines to 120 MW. I would suspect that there was some other factor that stopped all turbines from being upgraded.

So I would be very surprised if Drax upgraded the power of the existing station.

The Wikipedia extract claims that the Cruachan power station can provide power for 22 hours, if the reservoir, which has a capacity of 7.1 GWh is full. A simple calculation gives an average output in 323 MW. Does that indicate an efficiency of 73.4 %, by dividing 323 by 440.

But no pumped storage system of the 1950s is 100 % efficient. The Ffestiniog Power Station, which opened two years before Cruachan has an efficiency of 73 %. , which appears to be in line with the figures for Cruachan.

Cruachan Power Station And Nuclear Power

Wikipedia says this about Cruachan power station and Hunterston A nuclear power station.

Construction began in 1959 to coincide with the Hunterston A nuclear power station in Ayrshire. Cruachan uses cheap off-peak electricity generated at night to pump water to the higher reservoir, which can then be released during the day to provide power as necessary.

Note.

  1. Hunterston A power station closed in 1990.
  2. Hunterston B power station closed a few days ago.
  3. Scotland now only has one nuclear station at Torness.

It looks like the method of operation will have to change.

Cruachan Power Station And Wind Power

The obvious replacement source of energy at night to replace the nuclear power is wind power.

As I write this the UK is generating 8.5 GW of power from wind turbines.

Surely, enough can be diverted to Cruachan to fill the Cruachan Reservoir.

Cruachan 2

Drax’s plans for Cruachan are based around the building of a second underground power station, which is not surprisingly called Cruachan 2. This page on the Drax web site describes Cruachan 2.

  • It will be a 600 MW power station.
  • It will be to the East of the current power station.
  • More than a million tonnes of rock would be excavated to build the power station.

The existing upper reservoir, which can hold 2.4 billion gallons of water, has the capacity to serve both power stations.

I think it is reasonable to assume the following about Cruachan 2.

  • Design of the turbines will have improved in the sixty years since the Francis turbines for the original power station were ordered and designed.
  • The turbines will now be precisely computer-controlled to optimise the operation of the power station.
  • The turbines will have a faster response, than even that of Cruachan 1, which will help to match output to demand.

But most importantly, I suspect that the efficiency will be higher due to improved turbine design.

I can do a simple calculation, where I will assume the following figures for the two power stations.

  • Cruachan 1 – 440 MW – Efficiency – 73 % – Full Power – 323 MW
  • Cruachan 2 – 600 MW – Efficiency – 80 % – Full Power – 480 MW

It looks to me that 1040 MW can be used to store water in the reservoir and at this rate it would take 6.8 hours to fill the reservoir. With just Cruachan 1 in operation, filling the reservoir would take sixteen hours.

It looks like with moderate winds generating sensible amounts of electricity, it should be possible to fill the reservoir overnight using both Cruachan 1 and Cruachan 2.

When running flat-out, the combined station can generate 803 MW. At that rate it will generate the power for just under nine hours.

The Wikipedia entry for Francis turbines says this.

Francis turbines are the most common water turbine in use today, and can achieve over 95% efficiency.

Applying 95 % Efficiency to Cruachan 2 would give the following.

  • An output of 570 MW for Cruachan 2.
  • A total output of 1010 MW for the combined station.
  • This would mean the combined station could deliver 1.01 GW for just over seven hours.

Modern control technology would probably be used to ensure that the output of the combined Cruachan station filled in the gaps between demand and supply.

Could The Size Of Cruachan Reservoir Be Increased?

This would increase the amount of energy stored.

I suspect that it probably can’t be increased, as any increases would have been done by now.

Conclusion

It looks like very good engineering to me.

  • There is a good chance, that on most nights, the reservoir will be filled using wind energy
  • The maximum output of the Cruachan power station has been more than tripled from 323 to 1010 MW.
  • There has been no increase in the size of the Cruachan reservoir.

Scotland will now have a GW-sized hydro-electric power station.

 

 

January 11, 2022 Posted by | Energy, Energy Storage | , , , , , | 4 Comments

Could Drax Power Station Solve The Carbon Dioxide Shortage?

Drax Power station is the largest power station in the UK, with a  2.6 GW capacity when burning biomass.

It has also been a regular target of environmental activists complaining of the power station’s carbon dioxide and other emissions.

But could it be an unlikely saviour to replace the carbon dioxide that comes from two fertiliser plants run by the CF Industries, that have been shut down by high gas prices?

I wrote about the shortage in Food Shortages Looming After Factory Closures Hit Production.

Two and a half years ago I wrote Drax Becomes First Wood-Burning Power Plant To Capture Carbon, which was based on an article in the Financial Times.

I said this about the report.

This news has been treated in a more sensationalist way by other news media and sites, but the FT gives it very straight.

Drax power station is running an experiment, that removes a tonne of carbon dioxide a day.

But that is only the start of the process and most of it is released to the atmosphere.

They are currently, looking for profitable and environmentally-friendly ways of disposal, including selling it to beer manufacturers.

Didn’t we have a carbon-dioxide shortage a few months ago?

Now is probably a good time to dig a little deeper into what Drax is doing.

The Wikipedia entry for Drax power station has a section called Carbon Capture And Storage.

This is the last paragraph of the section.

In May 2018, Drax announced a new carbon capture and storage pilot scheme that it would undertake in conjunction with the Leeds-based firm, C-Capture. The focus of this pilot will be on capturing carbon post combustion from the biomass burners as opposed to the coal burners. Drax will invest £400,000 into the project. The company, C-Capture, is a side company of the Department of Chemistry established at the University of Leeds. This would yield about 1-tonne (1.1-ton) of CO2 stored per day from the process, which could be sold on for use in the drinks industry. The pilot scheme was launched in February 2019. The capture of carbon from biomas burners is known as Bio Energy with Carbon Capture and Storage (BECCS).

Who are C-Capture?

Their web site is very informative and this page is called Our Story, which explains the project at Drax.

We designed, built, and installed a pilot plant and have been operating it on site, with real flue gas, since early 2019. The data gathered from this trial is feeding directly into the design process for a full-scale plant, with a target of 10,000 tonnes of CO2 per day captured from one of Drax’s four biomass fired boilers. A recent development has been the installation of equipment to bottle the captured CO2 to allow other organisations to test their own developing technologies with genuine Drax derived CO2.

That looks like a result to me for C-Capture.

This page is called Technology and has a very neat interactive guide to how the technology works.

Conclusion

This company has some very special technology, that has a lot of applications.

It is also significant that Drax and BP have taken a shareholding in C-Capture.

 

 

September 18, 2021 Posted by | Energy, World | , , , , , | 3 Comments