Monday, 30 March 2015

One of the windiest nights of the year sees Ireland dependent on UK coal

With storm like winds hitting Ireland tonight, lets see how our electricity system is coping.

Jetstream Forecast

Between 9pm and 10pm wind speeds rose all around the country apart from 4 locations (click on picture to zoom in) :

So how efficient are our € 4.4 billion worth of wind turbines (2,200MW) at converting this energy sweeping across our country into power ?

Well at 9pm, they were producing 1,631MW and approx 218MW was curtailed. In otherwords, we shut down 218MW of wind power, about 12% of the potential power:

In the next hour, wind speeds rose in most areas around the country, notably in Cork and Donegal where most of the wind farms are (see Met Eireann data above).

Well, it turned out that our wind farms could not make use of this additional wind. Instead, wind generation dropped to 1,374MW, a drop in output of about 16%. Curtailment of wind rose significantly from 218MW to 483MW, an increase of 220%.  So 26% of available wind generation had to be dumped. Wind farm companies that have "Firm Access" will be compensated for this.

At 9pm we were importing 378MW from the UK (EWIC in the above graphs). By 10pm, we were importing slightly less - 340MW. Demand dropped in the same period from 3,790MW to 3,464MW, a drop of 326MW. As wind and UK imports do not provide the same type of power as that produced by conventional sources  - they are termed non synchronous generation sources - there is currently a cap of circa 50% on their use in the system at any one time (more explanation here). We can work out that total non synchronous generation (wind plus imports) at 9pm was 53% of demand, while at 10pm it was at a safer 49%. 

So part of the reason for all this curtailment of wind was to bring wind generation down to a safer level for system stability. But they had another option - switch off the UK imports and replace with the excess wind. But instead it seems that commitments made to the UK National Grid, or some other reason, meant that we were using power generated in the UK for 10% of our needs while at the same time shutting down 26% of available indigenous wind power. And what was this UK power made up of ? Well, the largest share was dreaded coal at 30% (which we are all taught to despise) and behind that was the even more dreaded nuclear (which we are all taught to fear) at 23% :

One can only wonder. Is there anyone left who actually thinks the people in charge know what they are doing here ? 

Why are we building more wind turbines when we are dumping more and more wind power ?


  1. And that is a question for the redoubtable Mr. Bob Hanna, Chief Technical Advisor at the Department of Energy, and the brains behind Irish national energy policy.

  2. As you exceed nighttime demand with installed capacity more of the output produced is waste energy. The amount of waste energy produced will increase as you add capacity. The 37% target is impossible to achieve. It should be abandoned. To avoid the fines we should start, as soon as possible retooling, Moneypoint for biomass before it is too late.
    With regard to the DCENR. I think they read to many Danish Fairy Tales and these were not written by Hans Christian Anderson

  3. There was an old song called Lanegan’s Ball which went like this.

    Three long weeks I spent up in Dublin,
    Three long weeks to learn nothing at all,
    Three long weeks I spent up in Dublin,
    Learning new steps for Lanigan's Ball.

    At 6.20pm to day, it is very windy in Ireland. Trees are being blown about and I estimate wind speed at 24mph with gusts up to 27 mph. It is not approaching any level of danger in my opinion. Some of our wind energy is being paid to shut down while we are importing 407 mw of electricity from the UK. The 50% rule means that more wind energy could be allowed into the grid, but it is not happening. So we are paying to turn off Irish turbines while at the same time paying the British for imported electricity generated by fossil and nuclear fuel. An even more bazaar idea just occurred to me. Imported British electricity contains a small amount of wind energy, so we are paying to import British wind energy while paying our own wind generators to turn off Irish wind energy. Heh? Wha? The song continues:-

    She stepped out and I stepped in again,
    I stepped out and she stepped in again,
    She stepped out and I stepped in again,
    Learning new steps for Lanigan's Ball.

    If you saw it on Father Ted, you would say it’s not realistic LOL

    1. Thats very true Val, we are paying to shutdown our own wind, while paying to import UK wind. As Dougal Maguire would say "Whats all that about Ted?"

  4. There is a reasonable point here that we should expect higher wind penetration and lower imports on a windy night, however allow me to nitpick a little.

    The forecast wind generation figure is based on a weather prediction. This is never quite right, so there is a difference with the actual wind generation amount. The difference between forecast and actual is not equal to curtailment as this post assumes!

    For most of the 30th March as we can see in the first graph above, forecast amount was greater than actual. Was that negative curtailment?

    But curtailment is real and annoys wind farm owners. The government is required by law to publish curtailment figures annually. In 2013 that amount was 3.5%

    In storms and hurricanes, wind turbines are designed to shut down, so this effect may have happened at times on the 30th. That's not curtailment either - it's a design choice to gear them to collect maximum energy for the most profitable range of speeds.

    This post appears to be based on figures collected at about 22.15 on March 30th. Later that evening at 23:45, the country began to export power to the UK and continued to do so until 07:45 next morning.

    I don't know the max permissible wind penetration on the Irish grid but it has been above 66% in Jan this year (and 74% in NI)

    I would like to see a broader collection of renewables in use in Ireland rather than relying completely on onshore wind. The interconnector to France is now on the horizon and Eirgrid see to be compromising with a way to strengthen the grid without ruining the countryside.

    1. Good few points raised there Ossian.

      1) You are correct about how curtailment was worked out. I can only work on information made publicly available. However, by first of all observing that wind speeds were getting higher from 9pm to 10pm and secondly by confirming this on Met Eireann we can see that more not less wind was available during this period. What we see on Eirgrid's site is that wind output was steadily dropping off as available wind energy was increasing as per Met Eireann. So we can deduce that curtailment was high. We can see that throughout the day, the forecast was fairly accurate, in fact, wind was overshooting it at times. So it really makes no sense that the forecast was over-estimated during this period. In fact, the evidence would tend to show that the forecast was under-estimated and potential wind energy was much higher. This would mean that the curtailment figure worked out in this blog is understated, not overstated i.e. curtailment was in fact higher than what I have worked out.

      2) I presume you mean that actual was greater than forecast ? This is not ideal either because the gas plants have been scheduled to ramp up here to fill the gap that was forecast to be left by wind. When wind output suddenly increases above forecast, the gas plant must be ramped back down again - "constrained off" - which leads to inefficiencies and less CO2 savings. Its not too big a problem in this case as the variance is small.

      3) The cut out speed for a wind turbine is on average around 55mph. This speed is rarely reached in Ireland. When you convert the ME data to mph, we can see that wind speeds were still under the cutout speed with the highest speed at circa 43mph.

      4) You are correct. Later that evening, we were exporting power to the UK. There appears to be a restriction on exporting during the day. I will address this in some depth in a future blog.

      5) You may well be right but you need to make sure you add in imports when working out the percentage - its (wind + imports / demand + exports). Demand also includes Pumped Storage and House Load which I am not sure is included in the published Demand figure so our figures may not be 100% accurate.

      The SNSP limit is set by Eirgrid at 50% at the moment but there are plans to increase this to 55% and eventually 75%. Eirgrid publish current SNSP limits here :

      6) I believe we are reaching saturation point with onshore wind. Perhaps it is time we looked at dispatchable options such as biomass.

    2. Yes, I meant actual was greater than forecast for most of the day!

      The rules around how the EWIC works are published by the CER but they are monstrously complicated and poorly communicated. In practice, it's clearly being used to import from the UK most of the time.

      There is plenty of data on Eirgrid's site but the definitions are not always clear. Some energy metrics are defined for official reporting purposed in the European directives but I wouldn't know how any of the figures on Eirgrid's web site were calculated. The max %wind penetration could be calculated in many ways as you suggest. The RES directive specifically excludes pumped storage from contributing to RES targets. This makes sense - otherwise you could use coal to pump water up a hill and then claim it was renewable energy when it flowed back down. If you used wind to pump it up, you'd double your renewable output by letting it down again!

      Eirgrid have been helpful whenever I've asked them to clarify something.

    3. Yes the rules are very complex and indeed has resulted in unintentional costs called Make Whole Payments of €800k per month - see here:

      Just to clarify, wind penetration is calculated as wind over demand. System Non Synchronous Penetration (SNSP) is calculated as formula above. This is from Eirgrid's own documents.

      You are correct that pumped storage is not counted as RES. What I meant was that at night Turlough Hill uses grid power (in fact it is a net consumer of power) so this has to be added on to demand aswell as house load of other generators i.e. the power that a power plant or wind farm uses which is about 2% - 3% of power produced. So to get a completely accurate wind penetration / SNSP figure you would have to include these in demand. From reading Eirgrid's documents I think this is how Eirgrid calculate these.

  5. I met the Energy Regulator in 2011 for two hours and I got hold of most regulations and documents published by them and Eirgrid since then. It was part of a quest to find out what was going on. Prior to that and not connected with it, I studied financial accounting, quantitative methods and management accounting as part of a degree course 1999 - 2003. While I did manage to get to understand how all electricity is paid for in some ways, the method is horrendously complicated. The accounting method may have been designed for operators only, but it presents a huge barrier of ambiguity to anyone studying the effects of wind energy on the grid. Seeing that consumers are constantly bombarded by spin, advertisements and claims about how wind brings down the price of electricity, I would expect they would try to keep the public informed. There is no liaison person, no transparency. At a public consultation event last year in the Ballsbridge Hotel, attended by the minister Alex White, I raised this point and a department official admitted it was too complicated and should be simplified. I stated that it would never be simplified, because it was part the misinformation. They did not take issue with me. In fact in one document it stated that many supliers did not understand it either. Financial accounting is based on agreed standards with no guesswork. The electricity market payments schemes regulations contains words for which there is no interpretation provided. You could take 20 meanings form some sentences. After 5 years of dedicated investigation and dozens of access to information requests, and engagement with officials, I never could find out what is paid in CONSTRAINT payments. An average of 26 million euros is paid in -CAPACITY- payments to wind annually. One access to information reply on the subject stated that there was more than one avenue to receiving constraint payments depending on the contract and it left me more confused than ever. The regulations provide limited micro information, but another way to study it is by macro assessment. That shows that in Denmark, Germany, Spain and Ireland the amount of fossil fuel used in generation is not reduced with large wind, nor is the amount of co2 emissions. See my video "valmartinireland you tube" The information published on line by Eirgrid, the British grid and many other grid operators does show specific detail such as the night of the 30th March 2015 and if watched carefully, a pattern emerges, That is that EU and the Irish government have told the department to do this, irrespective of outcome, but I know and so do many others what that outcome is. The recent winds were not strong enough to force turn off for safety. The fact is we were importing 407 mw of British power when I checked and when our wind was optimised. For all we know, wind generators may be paid constraint payments based on their capacity, when in reality they would have forced shut down or wind wake might prevent them generating anyway.

  6. Just as you mention interconnector 'bias', this has recently been raised in a SEMO presentation (P.6):

  7. The carbon footprint for all power coming in on the interconnector is levied on Britain. (point of production). The carbon footprint for all Polish Coal and other fuels imported into Ireland is levied in Ireland (point of consumption). Perhaps someone would explain the dichotomy. If the power coming in on the interconnector is cheaper and free of carbon penalties, then why don't we install 1.5 GW more. We can use up to 50% non-synchronous power and its dependable. This would drastically cut our peaking OCGT generation for all months other then December to March. No investment in plant would be needed, staff costs and pensions would fall to the UK. Convert a quarter of Moneypoint to wood chip and even the greenest of EU commissioners would be signing our praises for reducing carbon. Meanwhile massive bribery was uncovered at Alstom.,d.ZGU So what is really going on.

  8. On Ossian's point about measuring curtailment; This can't be measured by subtracting actual wind generation from forecast WG. WG above 50% of demand must be curtailed, irrespective of forecast WG. If there is no interconnection and demand is 3 GW, & WG is 1.5GW, there is no curtailment. If wind rises to 2 GW, then there must be .5GW curtailed. (3/2) - 2 = -.5. In this situation if forecast WG were zero, .5 WG would have to be constrained down, if there were 2GW forecast WG, .5 would still have to be constrained down. If you cannot find published curtailment figures, then you must deduce them from the wind conditions. On this particular night, the wind was very strong, near perfect. It increased slightly towards late evening, but wind use decreased in line with demand. Eirgrid used to denote this with a curl on the graph. When wind speeds remain constant (or increase) and demand decreases, any reduction in WG must be caused by curtailment. At the time I checked it, we were constraining WG while importing .407 GW from the UK. Imported power is non-synchronous too, so it raised the question; Why were we importing UK power while curtailing our wind power? It also raises the question of what would happen if we had double wind capacity (4GW). We would be curtailing about 2.5GW of WG while importing .407 from the UK. It also raises the question of what would happen if the Midlands Energy for Export project was built. Say 4 GW capacity. Would Ireland be exporting raw wind electricity and importing a UK mix of electricity simultaneously? Who would pay the curtailment of Irish Midland WG when the UK did not want it? The "Energy Bridge" that Eddie O'Connor was talking about would have to be capable of carrying all the Midlands power on such a night which would be costly. Say 4 GW. This would only be used about 6 days per year. 2 GW would do 75% of the time, but then who would pay curtailment fees when it increased above that on those 6 days? I put this in a submission to the the British Government. I got no reply, but they withdrew from the project shortly after. Now its going ahead for the home market so we know Irish consumers will have to pay its constrained fees. Remember all capacity must break even and make some profit to remain viable. Where it gets its money from does not matter, it must be paid and the only paymaster is the consumer. I will leave it to readers to decide in which of the two countries those consumers will live.