Something Fishy in the air?

I have noticed that wind power delivered to the Grid is always less than 6 GW, no matter how windy it gets. This was clearly demonstrated  on October 21st when wind speeds across the country reached around 50 mph for most of the day. The  wind output was simply bumping along continuously below 6 GW. Something fishy is going on – What is it?



The heart of the problem becomes clearer once  you start looking at  the constraint payments made to  wind farms under the Grid’s ‘balancing mechanism’ (see: Large wind farms were paid a staggering £2 million on 21st October to disconnect from the Grid. These payments are priced at over £90 for each MWh of ‘generated’ wind energy which is then simply thrown away !


Nor is this an isolated incident. Over the past year constraint payments have been increasing continuously as more capacity has been added. We can see similar periods over weekends last August and April. All these hidden costs for wind are passed on to the consumer through their monthly bills.


The UK installed wind capacity is 11.2 GW but the effective load capacity on a perfect day of wind is apparently only around a maximum of 60 %.  The Grid simply cannot handle more than 6GW of instantaneous wind power, whereas it has no problem with 30GW of Coal or Gas. I think the problem lies in the Grid topology which is based on large power lines to central generators. The high voltage connections to dispersed wind farms cannot handle large power, and this is made worse by unpredictability. There is really no point adding any new wind capacity until the underlying infrastructure is upgraded. But how much would it cost to completely redesign the National Grid, and is it really worth it when we could simply build large modern gas and nuclear plants compatible with the existing Grid?

This message of course is not what the green Wind lobby want to hear. They want to instal as much as possible because they can’t lose. They get paid whatever happens reaping handsome profits from ‘phantom’ energy. Why are they not also charged for the extra expense to upgrade the Grid?

Finally lets look at the headline wind energy statistics that are often quoted. Renewable Energy UK quote that the UK fleet of wind farms generate 27,263,077 MWh of Energy each year. This is based on DECCs own DUKES review of on-shore and off-shore capacity factors (27.82%). So let’s now look at the actual electrical energy supplied to the Grid over a full year of operations. I have integrated the total energy supplied to the grid over the last 13 months based on hourly monitoring.

Power delivery by Fuel type to meet Peak demand every day since September 2013. Weekdays peak demand occurs around 18:00 and fat weekdays around 20:00.

Power delivery by Fuel type to meet Peak demand every day since September 2013. Weekdays peak demand occurs around 18:00 and at weekdays around 20:00.

The total electrical energy  supplied to the Grid by Wind farms between  1st September 2013 and 1st October 2014 was 22,833,000 MWh. The total energy generated in a 12 month period September to September was 20,217,523,383 MWh.  This demonstrates that up to 26% of the reported energy paid out to wind farms is simply  thrown away. This fact is well hidden from public scrutiny because we all pay for such wastage through our electricity bills. Wind drives energy prices up. DECC and the Wind industry would prefer you not to know because it undermines their economic case for green energy.

Similarly the real ‘savings’ of CO2 emissions from wind were 3 million tonnes less than the official DECC figures of 11.7 million tonnes, and which also ignores the  increased emissions of Gas plants to balance Wind.  The real capacity load factor of Wind Farms was 20.6% and not the quoted 28.7%, once you take into account the discarded excess wind energy.

The real costs of Wind electricity should  be revised upwards by  35%. Only if and when the Grid gets upgraded to handle multiple power lines to such a dispersed energy source as wind can the current DECC and wind industry figures be believed. The costs of upgrading the Grid are enormous and must be factored into the real costs of expanding wind energy. Until the Grid is upgraded  it makes hardly any sense at all to add any new UK wind capacity. That is unless you are a wind operator with  guaranteed 20% return on investment underwritten by the UK government.

About Clive Best

PhD High Energy Physics Worked at CERN, Rutherford Lab, JET, JRC, OSVision
This entry was posted in Energy, renewables, Science, Technology, wind farms and tagged . Bookmark the permalink.

37 Responses to Something Fishy in the air?

  1. Your article is rather like someone arguing about the number of leeches to apply to a patient.

    It’s not the number of leeches, or their size or anything else that we should be discussing, but whether they are any benefit whatsoever.

    And the answer to that has always been no.

    • Clive Best says:

      Agreed, but to win the argument you have to stick to facts and evidence. The evidence says that current government energy policy is simplistic at best, and either plain bonkers or cynical at worst

  2. gmlindsay says:

    Excellent analysis Clive – constraint payments have always been highest when there are high winds – large parts of the UK grid simply cannot cope – especially Scottish Highlands. Also there is presently limited capacity in the interconnector from Scotland to England resulting in Whitelee (and a few others in the South of Scotland) seemingly always being paid constraint payments

  3. Doug Brodie says:

    Have you quoted total Sept to Sept actual grid wind energy in kWh instead of MWh? Your average daily figure seems out as well. The 26% number for energy thrown away stacks up using grid annual as 20,217,523MWh against RenewableUK’s annual energy produced 27,263,077MWh. I note that Dukes 2014 Table 6.4 p190 gives 2013 onshore plus offshore wind as 28,433GWh, close to the RenewableUK figure (dates unspecified).

    • Clive Best says:

      I think the figures are correct. If we take the official figure of 11.2 GW capacity and take a load factor LCF the we have yearly generated energy =

      11200 x 24 x 265 x LCF = 98112000xLCF MWh.

      So with LCF = 0.28 we get 27,471,360 MWh.

  4. Roger Andrews says:

    Hi Clive:

    A dumb question.

    You say Large wind farms were paid a staggering £2 million on 21st October to disconnect from the Grid. These payments are priced at over £90 for each MWh of ‘generated’ wind energy which is then simply thrown away !

    Once they’re disconnected from the grid there’s nowhere for the power to go, so presumably they have to switch the wind farm off. But if they’re switched off how do they calculate the MWh of wind energy that gets “thrown away”?

    • gmlindsay says:

      That’s a very good question, Roger. A colleague of mine has been looking at this issue and it would appear that there is a tendency for the grid to allow the constrained off facility to claim these amount of money on the assumption that the turbines are at maximum capacity (and for extensive periods) – which, as we all know is only very rarely. So, not only does the developer get large payments per MWh, he also gets much of it assuming maximum power. This cannot be right!!!

  5. fujirobin says:

    Who else gets constraint payments and how much?

    • clivebest says:

      If Gas and Coal plants are ‘constrained’ they actually pay the GRID money for the saved fuel costs. The payments to wind farms are supposed to compensate them for the lost lucrative subsidies (ROCs, LECS). However the Renewables Energy Foundation has discovered.

      What has become clear over the last year is that the amount charged by wind farms is very significantly in excess of the value of the subsidies foregone. For example, the average price paid to Scottish wind farms to reduce output in 2011 was £220 per MWh, whereas the lost subsidy is approximately £55 per MWh. The amount paid by conventional plant such as coal and gas was approximately £34 per MWh to reduce output in 2011. Ultimately the cost of balancing electricity is paid by the electricity consumer so this large difference in cost is not in the consumer interest.

      Furthermore it appears that there are some confidential agreements between the Grid and some very large wind farms for constraint payments which are not in the public domain. REF estimate that the total constraint payments made to wind farms are really double the published figures.

      One possible reason to hide these extra constraint payments, is to artificially lower the quoted price/MWh for wind energy to make it appear to be competitive with say nuclear.

  6. fujirobin says:

    I was under the impression (not sure where from) that when a constraint was needed there was some form of bidding process and the Grid accepted the best offer…. is this wrong?

  7. Pingback: Clive Best: Something Fishy in the air? | Tallbloke's Talkshop

  8. fujirobin says:

    I thought I’d read somewhere that gas generators got shedloads more than windfarms –

    Where is the audited data made public? Having access to the facts would help any debate. Or do National Grid deem it all private and condidential ?

    • gmlindsay says:

      The bidding system resulted in some wind operators getting as much as £200/MWh and Ofgem instructed the NG to cut the prices back. Nowadays the typical price is around £75/MWh. There is no audited data – only that which is published on the Renewable Energy Foundation web site. Wind industry hides behind the “commercially sensitive” banner

    • Clive Best says:

      I think there is a fundamental difference between Gas and Wind.

      As far as I understand it Gas operators bid a price in advance for power projections over the next 24 hours. At peak hours the price is higher than at night. Lets suppose the price is 70 pounds/MWh and the operators are contracted to provide 60,000 MWh of energy for £4.2M. The plants are ramped up to meet the requested peak demand of say 30GW. but they get constrained by the balancing mechanism to just 50,000 MWh. They ramp down the plants down. They must actually pay the Grid back for the fuel costs saved – say £0.5M. The constraint payment is then £0.2M

      This may sound a lot but don’t forget that Gas provides 30-40% of the UK energy needs while wind provides just 5.6%

      Wind on the other hand does not bid for future power demands because it is uncontrollable. It has a guaranteed price per MWh no matter when the energy is produced. If the wind is strong at 4am when demand is very small it still gets constraint payments of around £90 per MWh. Fuel costs are zero unless you include the extra gas burned balancing erratic wind output on the grid.

      Wind is the Goldilocks energy source.

  9. tallbloke says:

    Great post Clive, I’ve reblogged it for wider discussion and linked back.

  10. Frank says:

    The value of wind power depends greatly on how accurately it can be forecast. A grid operator needs to deliver power to his customers with high reliability. 99.7% reliability is still one outage per year, and National Grid is required plan for 99.7% reliability. If weather forecasts suggest wind is going to generate 6 MW of electrical power 1 hour, 4 hours or 12 hours in the future, what is the 99.7% confidence interval around this forecast? Remember, wind power in theory varies with the cube of the wind speed. A 10% over-estimate in wind speed is a 30% overestimate in power output. A forecast with a central estimate of 6 MW may turn have a 99.7% confidence interval of 4-8 MW or 3-9 MW. If the deliver of wind power is 2 or 3 MW below the forecast made 1, 4 or 12 hours earlier, where is the missing power going to come from? How fast can it be brought online? Grid operators always keep some generation capacity operating in spinning reserve to meet unexpected demand or outages, but this reserve will needs be expanded when wind output is high. Customers pay for this spinning reserve and CO2 is emitted when the reserve is provided by fossil fuel plants. (In Denmark, the reserve is provided by hydroelectric power from Scandinavia that can be turned on almost instantly.) This problem is much less severe when 0.6 MW of wind power is forecast than when 6 MW is forecast.

    National Grid has discussed some of these problems in rather vague terms in documents that can be found online in connection with their “Gone Green” scenario for getting 30% of electricity from wind by 2020. As best I can tell, current 99.7% confidence intervals for wind power 4 hours in the future were about +/-50% and they were hoping to reduce this to +/-30%.

  11. Clive Best says:


    Your analysis is correct but there is no doubt that wind has introduced much greater uncertainty than before into the Grid’s planning. It also means that the spinning reserve needed has increased significantly . Previously the risk was of a single large power station going off line – for example a nuclear plant being forced to shut down. To cover this risk the Grid needed a reserve of say 1-2 GW. However with a stochastic source of energy like Wind the reserve must now be increased to cover sudden drops in wind output. Even if the wind strength forecasts are improved, it is still the case that output can drop from 6GW to 0.2GW in 12 hours. This means that a reserve of fossil fuel power equal to the maximum wind capacity must be available within a 12 hour timescale as well as keeping a spinning reserve now increased to 2-3 GW. All these extra costs are not included in the price of Wind energy. They should be factored in.

    Scandinavia is indeed in a much better position with hydro backup. Unfortunately that is not an option for the UK.

    My solution is to introduce proper market pricing for wind. The price paid for each MWh should depend on demand. Wind would get paid a high price at peak times – 18:00 on week days and a low price at off-peak times – 4 am. Then the problem gets shifted to the operators and they must then solve the energy storage problem to maximise returns. Right now there is no incentive for wind farm operators to implement a storage scheme. They can’t lose as they get paid £90 – 150 per MWh guaranteeing them a risk free ~20% annual return on investment. This scam must end. Each wind farm would then have to implement an energy storage solution so as to provide power when it is actually needed rather than randomly as now. If they are unable to do that economically then wind power will be shown to have been a failure. Why should the consumer carry all the risk ?

    Incidentally I think you meant to write GW rather than MW above.

  12. fujirobin says:

    Frank – you need to consider the opposite too – if 0.6GW is forecast and 3GW of wind turns up, the Grid have to take the wind power and presumably pay the thermal generators to back off.

    As to “value” – there is usefulness to the grid and there is value to the customer. As Clive says a unit in the middle of the night isn’t worth the same as one at peak time in winter.

  13. Frank says:

    Clive: Thanks for the reply. Yes, I meant GW, not MW.

    The grid needs to have the generation capacity to handle periods where there is no wind power. In theory, that generation capacity can always be brought online to meet any FORECAST drop in wind output – IF the forecast is accurate and made far enough ahead of time. In their online documents, National Grid discusses their ability to forecast wind output 4 hours in the future, which sounds like the amount of time it take to bring additional fossil fuel capacity online from a cold start. They also discuss the legal requirement to plan for 99.7% reliability, the reliability of their forecasts (in standard deviations), and their plans to double their operating reserve. However, they don’t put the whole picture together in an easily understood manner (that would annoy politicians and regulators). Grid operators normally pay some generating plants to wait in reserve and then come online for a few hours to meet the normal daily peak in electricity demand. Now they need additional reserves in case 20 mph winds occur when 25 mph winds were forecast. In theory, that would lead to a 50% drop in power output from wind farms. If 8 mph winds appear when 10 mph winds were forecast, the same 50% deficit in power output is trivial, because 15-fold (2.5 cubed) less power will be forecast from 10 mph winds than from 25 mph winds.

    Your post suggested that something fishy is occurring when the wind is strong. Strong winds demand a much larger reserve to deal with forecast uncertainty. The fact that you are observing strange behavior when winds are highest suggests to me that the forecast uncertainty/reserve problem may be responsible.

    I certainly agree that we would be far better off if economic forces determined where we got our power from. Unfortunately, power distributors are natural monopolies and invariably regulated by public authorities. We won’t have true competition among power generators unless there is excess generating capacity available during times of highest demand when markets are de-regulated. The public wants fewer, not more, generating plants near where they live – especially coal plants. Current regulators control costs by limiting investment in capacity, because power companies are “entitled” to a certain ROI on their investments. You can read about the mess California made at the following link and perhaps find more information from James Sweeney at the Hoover Institution (a think tank where the free market is respected).

    As best I can tell, the free market solution is to tax CO2 emissions and return the proceeds to citizens through rebates or tax cuts. However, the conservatives hate all taxes, the liberals benefit from picking winners and losers, and everyone hates highly visible taxes.

  14. Frank says:

    Fuji: It is unlikely that 0.6 GW of wind power generation will be forecast and 3.0 GW delivered. That is a 5-fold difference in output and the cube root of 5 is 1.7. That means the wind speed would have to be 70% higher than forecast. 35 mph instead of 20 mph. The numbers I showed above were for wind speeds only 10% and 20% different from forecast, but – since power varies with the cube of wind speed (in theory at least), that becomes a 27% and 49% drop in power output (90% and 80% cubed). As best I can understand, documents online at National Grid’s website suggest that current forecast accuracy is +/-50% for power output at the 99.7% confidence level.

    Inaccuracy in forecasts cost the consumer money and cause CO2 emissions even though wind power is being used. Most of the cost of wind power come from the fixed costs needed to build the wind farm. Operating costs for wind are low, leading Clive to wonder why wind farms are being underutilized with winds are optimal. Fossil fuel plants spend a lot of money on fuel and cost much less when they are idle. When wind power is under forecast, customers appear to be buying their power twice – once for the capital cost of the underutilized wind farm and a seond time for the fossil fuel that wasn’t really needed. Grid operators can’t afford blackouts from over forecasting wind power, so they force their customer to pay for a large reserve in addition to the wind power itself.

    Electricity generated from non-wind sources can be forecast with a high degree of accuracy and reliability. Wind power is less useful because it can’t be delivered when needed AND because its delivery can’t be forecast with reliability.

  15. fujirobin says:

    Frank – reading your California link – what evidence is there of players gaming the UK electricity market so far? bidding for constraint payments has been mentioned – what else goes on?

  16. Frank says:

    Fujirobin: I’ve read extensively about National Grid’s plans for getting 30% power of their power from wind by 2020. I haven’t studied how their generators are paid or how that system could be gamed. In general, I strongly prefer free markets, but California shows that it can be very risky to move from a highly regulated environment to a state-misdesigned and -mismanaged “marketplace”. Power distributors are natural monopolies that are insensitive to market forces and probably need regulation. Politicians simply won’t let formerly-regulated prices paid by voters rise enough to reduce demand in a time of shortage, even when the result is blackouts. In California, the regulated power distributors were forced to pay “market” price for electricity (driven up by a drought-induced shortage and market manipulation), but weren’t allowed to pass those costs on to their customers (voters). Since electricity demand isn’t very elastic, the cost of easing a temporary shortage by raising prices can be very high. All three power distributors quickly went bankruptcy and had to be taken over by the state.

    With the potential shortage of electricity in Great Britain this winter, some power generators scheduled to close in the near future may be in a position to demand high prices. However, I suspect the government has the ability to force power generators to do whatever is needed to alleviate shortages. Attempting to create a “level playing field” and greater competition, California forced their regulated power companies to sell most of their generation capacity to other companies (outside California) and become primarily power distributors. So the state lost control over the power generators.

  17. A C Osborn says:

    Clive, Off topic, but this might interest you.

    • clivebest says:

      Yes that is interesting. There are 2 tidal bulges which each cross the equator during the lunar month. At the equinox spring tides at the full moon and new moon tend to be equal, but the asymmetry grows during the summer and winter.

  18. Harry says:

    Nothing Fishy. Just your ignorance..
    The reason is that the power lines to transport the electricity to where it is needed are not yet completed.
    The wind farms are located in different places to our coal fired power stations.

    • Clive Best says:

      Should not the huge cost of new power lines be included in the cost per MWh of wind energy? It also doesn’t make sense to increase wind capacity while the power line infrastructure cannot support it. A small number of new nuclear stations at central sites in the grid makes far more sense.

      I think the Grid should pay wind farms according to electricity demand. A high price at peak times and a low price at night. That way there would be a big incentive for the providers to solve the energy storage problem themselves. It makes no sense at all to pay up to £150/MWh for energy at night.

  19. Harry says:

    Wind turbines are only part of the package. We need all the other renewable sources (solar tidal, wave, geothermal etc. as well as some gas.)
    We need links to other countries.
    There is massive scope for energy efficiency.

    Most of all we need the smart grid and demand side energy management. We will need this regardless of the fuel sources.

    It will take decades to do everything.
    Meanwhile the system grows not always logically or symmetrically.
    But it will hopefully come together in the end.
    Most of the cockups arise as a result of two decades of inaction in the past.
    Energy is not sexy to politicians.

    The days of cheap energy are over.
    Unless fusion power can be made to work.
    (Little sign so far)

  20. Raff says:

    National Grid’s October monthly balancing services summary (which can be found at says in table 5.2.1 that “Payments to Manage Constraint” to gas and wind in October were £15.06m and £16.58m respectively. For the year table 5.2.2 says the figures are £30.57m(gas) and £27.13m (wind). Figures for coal are negative, indicating that coal generators paid money back to NG (for fuel saved perhaps). Note that these payments are separate from balancing costs (also listed).

    So wind and gas received about the same in constraint payments. And constraint payment predate the introduction of wind to the grid. So what is the issue?

  21. Raff says:

    If what you say were true, that 7 million MWh is being constrained off – thrown away – then at £90/MWh annual payments would be £630 million, against around £30m quoted (2014 to end Oct) by NG. So £52m per month against the £2m you quote for October. This level of misreporting would be greater than Tesco’s recent troubles. Wouldn’t someone notice?

    • clivebest says:

      When National Grid asks a
      generator to reduce output (constrain) we still need the electricity it would
      have produced to keep the network balanced, it’s just that we can’t move it in
      or out of a certain area. We manage this by buying energy from the market
      for another generator elsewhere on the network to increase output and make
      up the difference essentially.

      I may be wrong here but I strongly suspect both constraint payments to wind and gas are related to the same problem of balancing erratic wind output on the grid. If wind was not present at all then there would be no constarint paymenst to gas either. This is because gas has to balance the erratic output from wind at all times. Coal pays money back for fuel saved (carbon floor price included).

      Note also the scale comparison: Gas=40% of electricity generated while wind is 7%.

      • Raff says:

        You might be right – that NG deceptively quotes figures for balancing and constraint separately but that they are really two sides of the same coin. Or maybe some part of balancing relates to constraints on wind. As both constraint and balancing payments have existed since before the advent of renewables, historic data might show whether your suggestion is fact. But for now it is pure speculation.

        • Raff says:

          I think I mistook what you were saying – that maybe the *constraint* payments to gas are indeed the flip side of those to wind. Possibly, or possibly all of the balancing and constraint payments are interrelated. Interesting speculation that historic data might answer.

  22. Harry says:

    You can’t believe anything you read in the press these days.
    Journalists are by and large brain dead.

  23. Energy i says:

    The grid needs to be upgrading anyway and should be prioritised over the new countryside-wrecking fad of fracking, which has now been banned by many other countries.
    Production fluctuates and demand fluctuates. Nuclear plants very frequently have to close for periods due to safety issues – check the figures! If the input to the grid needs to be moderated, the elegance of the wind technology is that it can be turned off and on again quite easily. This makes wind farms the source of choice to limit because other sources that are nuclear or fossil fuels take a long time to stop and start again. You can’t take away the income from a company and expect it to survive so a constraint payment is made. The technology is useful to us because of the flexibility as well as it being clean. Solar and hydro are also agile in this respect, and wave powered generation, particularly sea bed systems are generally more steady and reliable, and should be invested in. Upgrading the grid and expanding the holding capacity needs to be a priority along with micro generation, which doesn’t tax the grid at all and with the plant maintenance costs borne by the householder themself.

  24. Pingback: Recent Energy And Environmental News – January 5th 2015 | PA Pundits - International

Leave a Reply to Clive BestCancel reply