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Swansea Bay–The Basic Facts

June 29, 2018

By Paul Homewood



This letter appeared in the Telegraph the other day:



Leaving aside the question of HS2, the writer shows a total lack of understanding about Swansea Bay, which is probably due in turn to the wholly amateurish way it has been treated by most of the media.


So, for Tess’ benefit, here are a few basic calculations:


  • Cost of lagoon – £1.3bn
  • Electricity produced – 532 GWh pa, which is 0.15% of UK generation
  • This is enough to supply on average 40,000 homes
  • Therefore the cost per household is £32,500
  • There are an estimated 107,500 households in Swansea, so the lagoon could not supply half of the town.
  • Even after the capital costs, ongoing costs will be substantial, for instance dredging and maintenance and replacement of turbines.

If Tess thinks that sounds like a good deal, heaven knows what a bad one looks like!

  1. Ian Magness permalink
    June 29, 2018 9:47 am

    “heaven knows what a bad one looks like”
    Throw that that obscene, useless and environmentally damaging white elephant in the bin and build a mixture of modern and gas and nuclear power stations, save billions and live happily ever after.

    • Charles Wardrop permalink
      June 29, 2018 10:07 am

      What strange and irrational priorities inform the thinking of our elected represetatives, from, e.g., Climate Change Acts, wind turbines, all-electric cars to allowing atrocities like the Iraq war and the like, remaining in the EU, notorious for its bossiness, corruption and waste.

  2. Athelstan permalink
    June 29, 2018 10:27 am

    “This is enough to supply on average 40,000 homes”

    i wonder how that calculation is made? Plus, notwithstanding the fact that £32 grand per house is some steep electricity price. Even if all the turbines are turning and at maximum load capacity its efficiency – I think, in peak periods times of demand, that the proffered – 40,000 homes is stretching the realms of possibility.

    BTW! please do not misunderstand me Paul, I am not taking you to task – at all, no sir.

    I just think that the PR for this now (fortunately) defunct scheme was too ‘good’ (probably not the correct term) – to be true.

    • Joe Public permalink
      June 29, 2018 4:55 pm

      “This is enough to supply on average 40,000 homes”
      I wonder how that calculation is made?

      Ofgem’s ‘Typical Domestic Consumption Values’:

      • It doesn't add up... permalink
        June 30, 2018 1:33 pm

        The TDCVs are of course the secret means by which our bills are shrunk, that make comparisons of energy prices via official OFGEM data over time almost impossible. We’re cutting back because it’s becoming so expensive. From 2013- 2015, the average consumer TDCV for gas was 13,500kWh, dropping to 12,500kWh and to 12,000kWh last year, while electricity Class 1 fell from 3,200kWh to 3,100kWh and unchanged last year, and Class 2 (I think supposedly white meter) from 4,600kWh to 4,300kWh to 4,200. The industry seems to think that these numbers aren’t necessarily representative of real consumption.

        Meanwhile, the 532GWh/a forecast generation figure is among the higher estimates of output. Originally in 2015, they were forecasting as little as 400GWh/a, before bumping the number to 495GWh/a for publicity. Taking the 532GWh/a figure over 40,000 homes gives an average of 13,300kWh – so if we include heating and cooking energy use it would be on the low side.

  3. Simon permalink
    June 29, 2018 10:34 am

    Why should I pay through the nose with higher electricity bills to subsidise more vanity projects. Mr Shorrock thought the renewables lobby would see him through to untold riches with his Cornwall quarry. Swansea should not be subsidised bybthebrest of the country either. All we would need was another 660 odd lagoons and we will match our current total generation of electricity. Except when the tide isn’t moving twice a day.

  4. June 29, 2018 11:09 am

    Surely the right reason for pulling the Swansea plug, while fully agreeing with the cost issues, is that it would have been dis-functional. It should have been cancelled if Shorrock and his pals had been paying US. And his grander plans compounded the stupidity.

    We are left wondering if our politicians, especially those in the Welsh Assembly Government, plus the New Labour group, Plaid Cwmru, the dreamy-eyed Liberals, and the soon to be departed Carwyn Jones (Lawyer) and a motley crew of farmers, hospital assistants, teachers and other scientifically unqualified rent seekers are uninformed, mis-informed, stupid, or just helpless.

    Perhaps instead of “helpless” I should have said “powerless” – but then the way they’re going we will all be that anyway.

  5. June 29, 2018 11:43 am

    It would seem that the only party that Tess could vote for, if she is concerned about getting a sensible and workable energy policy, is UKIP.

  6. Phoenix44 permalink
    June 29, 2018 11:50 am

    It’s ironic that this is the first sensible thing the Tories have done for a very long time. It’s also the first time in a very long time they have used proper economic analysis to make a decision.

    The letter shows what the Tories are up against in a way – I cannot believe that this woman has actually looked at the evidence for this. she has simply decided “it is a good thing” and so shuold be done.

    • June 29, 2018 1:39 pm

      She’s in medialand due to false picture the media give us.
      It’s quite different to the real world and its laws of maths.

      • Mike Jackson permalink
        June 29, 2018 3:09 pm

        To be fair to her, stewgreen, she is no more ignorant or ill-informed than the vast majority of the British population — including, I hazard a guess, quite a few of us here and elsewhere until we started asking questions and doing a bit of research.

        My own scepticism started from a) the fact that global warming failed my personal “sniff test” from the beginning and b) a longstanding distrust of the local Greens. Also that I had time on my hands to do the work needed to get a picture.

        It doesn’t take a lot of research to realise that climateers are, to say the least, sparing with the truth as are most eco-activists, but the one thing they are above all else is plausible. I mean, who could possibly disagree with looking after the planet we live on? And at that point they’re half way home!

        They can rely on soundbites; we have to explain why they’re wrong. Who wins in the modern “attention span” stakes?

  7. June 29, 2018 12:43 pm

    I am not a particular fan of the project, but the household figure for electricity is an awful measurement that is misused by both sides in these kind of matters. If the 1.3 billion was paid for by the average 60MW output with no interest costs of the 120 year lifetime is I calculated at about 2p per KWh. I reckon with maintenance costs and interest costs it is still expensive, but not a no brainer. The intermittency issues are real nevertheless especially as excellent tidal sites in the UK are in phase with each other.

    • It doesn't add up... permalink
      June 30, 2018 2:39 pm

      Do the same sum for Hinkley Point:

      Annual output = 3.2GWx85%x8,760 hours ~=24TWh/a
      Cost ~£24bn so £1/kWh/a
      Life 60 years gives 1.6p/kWh.

      Fuel cost is “negligible”.

      Financing cost matters, and you must include operating and maintenance costs too – not negligible for Swansea, as they will include dredging that will use as much diesel fuel as about 10% of the output, as well as maintenance of the turbines, sluices and the sea wall.

  8. Gerry, England permalink
    June 29, 2018 12:45 pm

    Probably as good an example of why Churchill said that just 5 minutes talking to the average voter was enough to make you question democracy – not that we have that in the UK anyway.

    • Charles Wardrop permalink
      June 29, 2018 9:24 pm

      He did say that one person one vote-our democracy- was the worst system-until all the others were compared!
      However, look at the outcome these days, especially in Scotland!

  9. June 29, 2018 1:48 pm

    There is no extra info in the Telegraph comments
    – One guy asks Iceland has geothermal, what’s our equivalent
    … eventually points out that would be fracking
    … which is politically banned.

  10. June 29, 2018 3:30 pm

    The joke is that wind turbines in Swansea Bay would probably be a better bet, but don’t count that as a serious proposal.

  11. mwhite permalink
    June 29, 2018 3:39 pm

    Don’t worry Swansea and it’s tidal lagoon will be for the fishes by the end of the century.

  12. tom0mason permalink
    June 29, 2018 5:26 pm

    But Paul you’re missing the point, the whole idea was to make the UK ‘World Leaders’ in the technology of virtue signalling stupidity!

  13. June 29, 2018 10:58 pm

    3,200 MW Hinkley Point C nuclear power plant [npp] will have a design life of 60 years at a [contracted] capital cost of £18,000 million; every year, it will generate 25,228,800 MWh of 24/7 electricity. By contrast, 320 MW Swanseas TL will have a lifespan of 120 years and a capital cost of £1,300 million; every year, it will generate 530,000 MWh of intermittent, grid-degrading electricity.

    It would take nearly 48 such tidal lagoons, at a capital cost of £61,882 million and occupying an area of 547 sq km, to generate as much of this problematic electricity every year as the 24/7 electricity generated by Hinkley from its 1.75 sq km site. The npp would have to be built a 2nd time, on the same site, using much of the same infrastructure to generate for 120 years – but this would only have a capital cost of £36,000 million.

    Why pay over 70% more for the delivery of a truly pathetic, intermittent, grid-degrading product that will forever require fossil-fuelled back up?

    Why desecrate hundreds of square kilometers of our near-shore sea beds, destroy precious ecosystems and wipe out species for such a pathetic product?

    Why use so much CO2 emitting concrete and millions of tonnes of quarried rock, with the attendant environmental destruction, for such a pathetic product?

  14. Jeremy Taylor permalink
    June 30, 2018 9:45 am

    There is a £1 billion gas fired power station not far from Swansea that generates 30 times the power.

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