How to use Scotland’s massive renewables output for a sustainable supply


As you know, we’ve had many days, weeks, of electricity supply from wind power at well over the 100% demand level. However, we remain susceptible to the Trumpian critique that we cannot rely on wind every day, even in Scotland.

Battery storage is showing signs of accelerated development that will lead to it being at least a partial solution:

£20 million Scottish renewable energy storage unit for Broxburn will be first in UK

First battery-powered hotel in UK is in Scotland

However, it seems unlikely that battery storage will be enough, so recent developments in pumped storage look interesting. From Energy Voice, yesterday:

‘The developers of a Highland pumped storage project claim their technology is tailor-made to fill the supply gap left by offshore wind. The developers of the 450 megawatt (MW) Red John project in Inverness, last night described the need to meet the potential energy gap as “urgent”. As the most advanced site in Scotland, the Red John project could generate enough electricity to power over 400,000 homes.

From Red John (no relation)

‘UK wind developers were paid £125 million in curtailment charges last year alone – in other words, they were paid not to produce electricity. Our plans will go a long way to help get the maximum benefit of new renewable energy for the country and the environment.’

From an earlier report here explaining how this technology would work, see:

‘In the last couple of years, there has been a growing a number of news articles and blog posts published about energy storage, particularly in the form of battery systems. This interest is very reasonable, and the news is exciting because these systems can fill in wind power and solar power electricity production gaps.  However, it appears as though pumped hydro storage is being overlooked, with all the hype about batteries. It still has huge potential to help balance clean, renewable energy. In fact, all the discourse about battery storage seems to be supporting the idea that this form of storage is going to solve clean energy intermittency issues, but there are gaps in what batteries can provide, so let’s take a look at pumped hydro so we can see just how large a factor it could become.’

‘Pumped hydro storage’ is, as far as I can see, the same thing as out long-established hydroelectric power stations, such as the one at Cruachan. Here’s how the US system is illustrated:


I’m no technologist so is it just a hydroelectric power plant of the kind we have decades of working with? If so, why is this technology not being talked about for storage? My first reaction is that perhaps our hydroelectric power stations generate all the power they need by themselves to pump water back up for storage. There may however be other sites which would need the electricity from renewables to achieve their full storage potential. I don’t know. The US report suggests that there are potentially around 22 000 pumped hydro energy sites in Australia and that Germany already has plans to use the technology to store around 23Gw by 2050 so there must be something in this.

Finally, of course, there are environmental and safety concerns with battery storage while hydro is, to my knowledge, safer and more ecologically sound.

As in some earlier pieces, this is a social scientist dabbling in the physical sciences and technology, but I know some readers are equipped to clarify or correct.



20 thoughts on “How to use Scotland’s massive renewables output for a sustainable supply

  1. David Connelly March 9, 2019 / 7:51 am

    There are two current sites in the UK where this pumped water storage happens already. One in Wales and one here in Scotland. Have we forgotten what was dug out in the mountains many years ago? Why look to US studies when there are examples here already.

    Liked by 2 people

  2. Dave Albiston March 9, 2019 / 9:30 am

    I’m no expert on this technology but on my tour of Cruachan I remember that it can that it can only give a short boost to the supply when folk put the kettle on at the end of Coronation Street. Maybe with a much larger reservoir at the top they could provide a more sustained supply?

    Liked by 1 person

  3. rovivorltd March 9, 2019 / 10:06 am

    Hi John,
    The idea of pumped storage is that it is available at times of peak demand and can be switched on and off quickly. Hydro stations startup times are very quick compared to fuel fired stations. At times of oversupply as referred to with wind and solar curtailment payments, the pump storage system would then draw power from the national grid and reverse the system to take water from the catchment loch and draw it back up the hill to the containment loch ready for the next peak in demand. What makes these systems so profitable after very high construction costs, is that they are relatively old, known, cheap technology which is easy to maintain. BUT the power produced is usually sold at times of peak demand/maximum price per unit produced as required. The station uses power from the grid during low demand/over production/low price per unit used times.
    So in a well run national grid with a combination of resources low demand overproduction can be managed and directed into storage solutions which due to supply and demand usage can pay for themselves very quickly
    Cheers for the good work John.


  4. Phil Bernstein March 9, 2019 / 10:19 am

    I’m sure I said this on this site years ago. I remember reading about a small island which is totally self sufficient in renewable energy. Wind power for electricity and at times of excess capacity it was used to pump water into reservoirs. At times of no wind the water was used to power hydro electric generators. Scotland has an abundance of water, hills and wind. Sometimes the simplest of solutions are the best.

    Liked by 1 person

  5. rovivorltd March 9, 2019 / 10:19 am

    Scotland has Cruachan and Foyers(Loch Ness) these are both 40 plus years old as I said previously they are a well known old design which could probably do with an injection of modern design and lateral thinking. The proposed Bristol Chanel tidal barrier is essentially the same principal with production dictated by the tides.

    Liked by 1 person

  6. gavin March 9, 2019 / 12:43 pm

    Best solution (for me) is to produce hydrogen from excess “green” energy: store/use as required: have it as a backup for windless days.
    You can use it in homes, power vehicles, produce electricity and move it round the country.

    I have also seen a twist on pumped storage. This involved raising a huge circular slab of stone/concrete in the manner of the old town gas storage units (gasometers?) by hydro, using excess power. The weight then acts as a pump, driving the water through turbines when required (as opposed to a “head” of water), and this system can be built anywhere. There is a cost to building it, and the maintaining of a sealed structure, but then it should last for many decades, and you can build as many, and as big as you need. The idea is similar to dropping weights down a mine shaft/ or a heavy wagon down a steep hillside.
    Scotland also has many southern facing hillsides, doing absolutely nothing, perfect for solar (and yes, you can get electricity from solar in Scotland).


  7. Legerwood March 9, 2019 / 12:57 pm

    Curtailment charges can vary widely from year to year. In years when they are high it is often a sign that upgrades are taking place to the grid to allow it to better handle energy from renewable energy sources. Under those circumstances wind farms in the areas where upgrades are taking place the wind farms are closed down.

    I have seen curtailment cost one year of £30 million and the next year £7 million.

    Worth remembering too that it is not just wind farms that attract such payments.

    Here is a link to a paper on the subject


  8. Alasdair Macdonald March 9, 2019 / 1:13 pm

    The key fact about renewables production and storage is that a RANGE of approaches – hydro, wind, solar, tidal, estuarial, wave – are all part of the mix. While wind, for example can be intermittent, there can be good production, say, in the south, while the east coast is relatively calm. Tidal and wave power are more predictable and, indeed, in the case of tidal, the ‘peaks’ traverse Scotland at the same rate as the tides, do.

    Similarly, there are a range of ways of storage, with pumped storage being a long established technology which can probably be made more efficient using modern materials and techniques. Battery technology is improving and, of course, hydrogen production, probably shows the most potential.

    Increasingly there is use of improved insulation techniques in building which not only reduce heat losses and so energy demands, but can also circulete better the heat in the building. These are increasingly being augmented by very local heat pumps and district heating schemes.

    Interestingly, Labour seems to be considering the establishment of a sovereign wealth fund (No, not Scottish Labour, which has never had a constructive idea for two decades, but the office of Mr John McDonnell. It is unlikely that Labour will win a GE in the near future. I have not seen details of what the assets are which will contribute to the fund, but, I suspect it will have to depend heavily on renewables, and, like oil and gas when discovered in the 1960s and 70s, these are principally in the Scottish land and sea territorial area (51% of the UK – and we are ‘too wee’????). I understand that the estimate is 25% of the entire renewables potential of ALL OF EUROPE! So, I imagine that Bodger Broon will be trotted out soon to tell us about ‘pooling and sharing’ – i.e. Scotland contributes the ‘pool’ and Labour ‘shares’ it amongst all of the rest giving Scotland a roughly 10% share – which will be presented as a ‘Barnet’ formula which gives Scotland a disproportionate share, because Westminster will be redistributing the wealth created by England to the ‘poorer’ areas.

    Incidentally, assuming Northern Ireland remains in the UK (and that is pretty much 50/50) given its coast on to Atlantic, it, will have a fair renewables – wind, wave, tidal, solar (south slopes of the Mountains of Mourne, Sperrins, etc – potential too. Maybe Harland and Wolff’s could be resurrected (with a fair and balanced recruitment policy! Lough Neagh is a huge ‘heat sink’ which could be used for heat pump purposes. Start serious planning on a bridge between Northern Ireland and Scotland!!


  9. George Shepherd March 9, 2019 / 5:21 pm

    Just check out exactly how many Hydro’s there are in Scotland you will be surprised and I have worked on a large number for them


  10. George Shepherd March 9, 2019 / 5:26 pm

    Should have mentioned that I have worked on all 4 at Cruachan two were originally English Electric and two were AEI (Associate Electrical Industry) Both now Quartz Elec Rugby


  11. William Henderson March 9, 2019 / 9:03 pm

    Another energy storage solution no one has mentioned is based on ammonia production coupled to ammonia fed fuel cells. Ammonia is nasty stuff but its production and storage is already large-scale and well understood. It is conceivable that ammonia could be used as motor fuel linked to car-sized fuel cells rather than hydrogen. It is liquid at comparatively low pressures (like LPG) and could fill fuel tanks in much the same way as LPG does at present. Exhaust is water – just like hydrogen.


  12. Sarissa March 9, 2019 / 10:44 pm

    The costs and practicalities of storage schemes for increasing penetration of wind power generation were the subject of a detailed report about 4/5 years ago by (I think) Strathclyde Uni. It had a lot of background data on Scottish power generation and usage, including storage for a range of periods up to 10 days and a wind power share up to 60%. It also included useful costs of constructing pumped storage systems as well as converting some/all of current hydro schemes as a storage resource.

    It would be really useful at this time to publish an update – maybe some of the environmental groups could help fund this?

    When I find the link tomorrow I will post it here.


  13. Alan Gordon March 10, 2019 / 12:41 am

    Here’s a link I read some time ago. It gives the present and in planning capacity of Pumped Storage Hydro for the UK.

    It looks as if PSH can work out relatively cost effective to build, sub £1000/kw, it does help with meeting sudden demand (contingencies). This will become more of a need as the percentage of fluctuating renewables, in the national mix, increases. Apparently some type of turbine can reach full output in seconds but require an electric supply to achieve this.

    I see a drawback and perhaps one reason why there aren’t more PSH. Pumping the power source up, to let it cascade down for electricity production is inefficient. It only works financially due to the disparity between peak and off peak electricity prices. Increasing the demand on off peak will put pressure on the pricing. This may be making the project investment unattractive.


  14. johnrobertson834 March 10, 2019 / 2:41 pm

    I worked for one year in Longannet PS, 1980, year of release of Alien. Scared shitless on my own durng nightshift.


  15. Ian White March 11, 2019 / 3:19 pm

    Pumped storage may well be one part of the “Energy Mix” especially to add power to the grid at peak times when a “fast run up” is required. However, nowadays the environmental lobby will campaign most vociferously and pillory elected representatives mercilessly to have such schemes binned, despite their need. It is now highly unlikely that schemes such as Cruachan would ever see the light of day. However, there does seem to be some progress to be made by conducting a review of current efficiencies of these older schemes with a view to ascertaining if investments in improvements can be justified. There is also more scope for run of the water schemes to be built. However, there are issues over ownership of land by large offshore owners.


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