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Constraint Payments Rise To £124 Million

February 17, 2019

By Paul Homewood




Constraint payments to wind farms last year cost £124 millions last year, at an average of £72.29/MWh

These are paid when there is too much wind power for the grid to handle, and the cost is added to electricity bills.

  1. Trevor Shurmer permalink
    February 17, 2019 1:27 pm

    Might be an ignorant question, but does the electricity not used but paid for by constraint payments still show on statistics as ‘renewable energy percentage’. In other words, they may say wind energy has contributed 20% say of our needs, have they included that power generated but not used and paid for by constraint payments. Does that make sense?

    • cajwbroomhill permalink
      February 17, 2019 5:54 pm

      Absolutely nothing (else) about windpowered electricity generation makes sense so you have likely spotted something though your suggestion is likely to be all too true.
      The whole corrupt, green movement purporting to defend us from adverse climate changes is riddled with lies and distortions, evidently put there by (now) Baroness Worthington, FoE staffer and protegee of Ed Milliband, which says it all!

      Time for repeal of Climate Change Acts (2008,9), before we become bankrupt.

    • Harry Passfield permalink
      February 17, 2019 8:42 pm

      Bloody good question!

    • It doesn't add up... permalink
      February 17, 2019 10:13 pm

      The total amount constrained off last year was 1,724 GWh. Energy Trends is a quarter behind with its data, but Q4 2017 -Q3 2018 total 55,800GWh of wind production. Curtailment was running at about 3%.

      The real driver for curtailment will be when wind generation exceeds demand overnight (typically around 20GW, but sometimes lower in summer), having allowed for the fixed nuclear element (say 6-7GW) and a quantity of flexible generation to handle grid stabilisation (perhaps another 3GW). As wind capacity continues to rise (it’s over 21GW now with the Hornsea startup), the frequency with which wind output exceeds the remaining demand will increase, and it will have to be curtailed if it can’t be sold to the Continent. There will be no market for it in Ireland, which will be in the same predicament: indeed, they will be seeking to dump surplus wind on the UK. I did a very simplified analysis of this a while back, which shows that as wind capacity rises, the marginal rate of curtailment increases roughly linearly, meaning that total curtailment increases quadratically:

      Current curtailment has been driven mainly by the lack of transmission capacity from and within Scotland to allow Scottish wind farms to supply Southern England. In theory, that should have been easing with the Beauly-Denny line and the HVDC Westernlink. In practice, it seems that new capacity at wind farms has outpaced new transmission capacity. Of course, all this extra transmission capacity that was never needed before adds to our bills.

  2. Joe Public permalink
    February 17, 2019 1:43 pm

    “Constraint payments to wind farms last year cost £124 millions last year, at an average of £72.29/MWh”

    Hornsea Project One produced power for the first time a couple of days ago.

    It’s to receive £155.53/MWh.

    As Constraint Payments are compensation for subsidies not received, does that mean its owners receive Constraint Payments of £155.53/MWh?

    • It doesn't add up... permalink
      February 17, 2019 10:18 pm

      I believe the answer is no. Constraint payments are based on auction type pricing, so the most expensive bids are not taken – unless that is operational reasons force that to happen, such as loss of transmission capacity. But it is onshore wind farms that risk being constrained off first among wind farms, though if at all possible it will be fuel using plants, whose bids for constraining off reflect the fuel cost they save (which is of course zero for wind)>

      • It doesn't add up... permalink
        February 18, 2019 8:33 pm

        I should have pointed out that the consequence is that the most expensive power gets priority for actual supply, while the cheapest is shut first.

  3. Joe Public permalink
    February 17, 2019 1:54 pm

    Two nuggets from the REF website:

    “Not all constraint payments are in the public domain. Where a private contract has been entered into between National Grid and a generator, the participants, volumes and price of the trades are not published. Thus, the user should remember that the Constraints Data shown on the REF website refers only to those trades carried out as part of the Balancing Mechanism. It appears from data reported in a Parliamentary Question that the annual wind farm constraints total of approximately £12.8 million made through the Balancing Mechanism in 2011 is nearly matched by a further £12.7 million in payments which are result of confidential bilateral trades and are not in the public domain. REF believes that such charges on the consumer should be visible to the market to ensure market transparency, and also to facilitate competition to reduce costs (see REF press release).

    Furthermore, when a wind farm is required to reduce output north of a grid constraint, another generator – almost always a flexible CCGT gas fired generator – is required to increase output south of that constraint to make up the shortfall in energy and to correct the level of the reserve available on the system. Thus in addition to payments made to wind farms to reduce output, additional payments are made for the fossil-fuelled generators making up the shortfall in energy and reserve to increase output.

    (My bold)

    • jack broughton permalink
      February 17, 2019 7:12 pm

      Many years ago we used to complain about the inflexibility of the CEGB regarding charges for developing power technologies. At least they were totally clear and transparent. This
      “trading” reeks of insider dealing and cover-ups. Generators used to be charged heavily if they offered power but could not provide it when demanded: the reverse applies now!

  4. A C Osborn permalink
    February 17, 2019 3:32 pm

    Why don’t they run all the Coal, Gas & Nuclear Generators flat out and ask for Constraint payments, oh I fogot they are not “Green” or “Renewable” so wouldn’t get any.

    • February 17, 2019 9:56 pm

      All they have to do is to make their energy bills transparent; so customers can see exactly where their money is going. They already have a daily charge, so why not a green subsidy charge? (itemised if possible).

  5. February 17, 2019 4:07 pm

    Nice work if you can get it. Can I get paid for not producing renewable heat when I don’t use my wood-burner?

    It reminds me of the letter written to Ed Miliband back in 2007 about the not rearing pigs business:

    • Graeme No.3 permalink
      February 17, 2019 11:27 pm

      Be careful about mentioning your wood burner.
      Under EU regulations burning wood pellets doesn’t produce CO2 and therefore can attract a subsidy e.g. DRAX. Should Brexit ever happen then there is a chance, remote as it looks at the moment, that commonsense will become fashionable.
      Thus wood could be classified as fuel and the government will put a tax on it. Then you will be badgered by public servants convinced that your failure to use as much wood in July as you did in January is ‘proof’ of malfeasance.

  6. February 17, 2019 5:57 pm

    I’m guessing that most of these payments go to Scottish windfarms, when their output exceeds the transmission capacity to England and NI?

    • Joe Public permalink
      February 17, 2019 6:14 pm


      “Such a constraint exists between Scotland and England. Increasingly more electricity is being generated in Scotland than can be used in Scotland, and the grid interconnections between Scotland and England are insufficient to take the excess electricity which is generated, usually at times of, often unexpectedly, high winds and low Scottish demand.”

  7. Ian Miller permalink
    February 17, 2019 7:13 pm

    I simply cannot believe that we can go on with such stupidity.
    When the Climate Changed Act of 2008 was passed, there was really very little real understanding of the effect CO2 had on Climate, but increasingly in the face of current but deliberately unreported global cooling while CO2 continues to rise, many climate scientists are now not so sure.
    Until sufficient of the Global Climate is understood, we should not be subjected so brutally to the effects of what has become such an economically damming religion.

  8. Jackington permalink
    February 17, 2019 8:53 pm

    How do schoolteachers explain this sort of thing to their pupils? Remember children this is a price worth paying to save the planet! Mummy and Daddy won’t mind.

  9. February 18, 2019 9:20 am

    Reblogged this on ajmarciniak.

  10. JoseDispatcher permalink
    February 18, 2019 9:42 am

    It is like in China! Variable renewables in China currently face high curtailment rates due to technical, market and operational constraints (around 18% wind, 10% solar and 4% hydro). It is expected to continue to fall through 2025 due to the completion of planned transmission corridors (and other policies).

    National Grid has to decide what is economic, investing in grid reinforcement or: spending money in the balancing market for transmission congestion relief; avoiding paying renewable energy curtailments. Has NG a plan to solve it?

    • It doesn't add up... permalink
      February 18, 2019 2:24 pm

      The NG plan is simple: expand its asset base as much as possible, to maximise their permitted revenue and profit That means building a grid system that is highly inefficient and costly. They’ve already managed to double the costs of electricity generation in just a few short years. Supporting inefficient renewables is right at the heart of their thinking.

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