Sunday, 14 February 2016

Meentycat Wind Farm

Meentycat wind farm is the largest wind farm in Ireland at 88.5MW. It is owned by Airtricity and located in Donegal about 20 miles from the sea in a hilly area. So it's very well located to take advantage of Ireland's best wind resource.

The following wind maps confirm that it is in one of the best locations in Europe :

It was built in 2004, with an extension in 2009, and consists of 38 2.3MW Siemens wind turbines. According to data from SEMO, it had a capacity factor of 31% in 2015 i.e. it generated on average 31% of its maximum output over the year. It operated for 88% of the time, i.e. roughly 9 hours in 10.

However, as can be seen from the below charts, the wind farm was generating between 0% and 2% for 18% of the time and 10% or less of it's output for around a third of the time. For just 1 hour in 10, it operated at a capacity factor of 75% and above. 

Capacity Factor
0% - 2%
10% or less
25% or less
75% or more

 Another way of looking at these figures is that for around a third of the time, the wind farm operated at between 26% and 74% of its max output, equivalent to the same amount of time it operated at less than 10% capacity factor. So there is an equal chance that the wind farm will generate mid range amounts of power as it will tiny amounts. There is greater chance (18%) that it will generate none or next to no power as it will very high amounts of power (10.5%).

So we can see that this is wind energy at it's optimum performance. Presumably, results would have been slightly better when it was first installed. Certainly, it's capacity credit was higher then, as there was much less wind farms (capacity credit is it's contribution to generation adequacy and is sometimes referred to the amount of conventional plant that can be decommissioned as a result of the new wind farm without posing a risk to security of supply. Capacity credit tends to decrease with the more wind you add). 

If there is a case for wind farms in Ireland, then it's within that dark blue line only in the map above and should have been restricted to around 1,100MW. The wind industry and government are fond of telling us that "Ireland has the best wind resource in Europe" but actually that only applies to a small portion of the island and is comparative to Scotland and North Denmark.


  1. The blunder being made is to count how much wind electricity is being produced rather than what contribution it makes to adequacy of supply. If a farmer goes to the local restaurant most days for his lunch costing 10 euros. The restaurant has to be prepared to serve him whether he arrives or not, On average it will have the same amount of customers each normal day and can do that. Say he goes 200 days per year costing 2,000 euros. If a caterer says it will supply him 200 lunches for 12,00 Euros, what will happen. If they arrive with 200 lunches on the 1st January, at least 195 will be rotten in 5 days. If it arrive daily at random, he may have other arrangements and will not want the those lunches. This is why the only way to measure wind is capacity credit

  2. To make some observations about this post
    Firstly 30% approx. capacity is a figure which is common across Ireland - Mount Lucas & 4 wind farms in Wexford are examples. Once you are up out of the rough air at say 80 or 100M (typical hub height) there is a more constant and even air flow and a more even ability to generate electricity.
    Secondly SEMO is missing one important data element - that of constraint - so from your figures you are not able to determine if the wind farm was able to but not being allowed to operate at its optimum capacity (constraint does not only happen at max wind speeds but can also happen at 70% or 80% of capacity) This can only have the effect of increasing the 30% capacity figures.
    Thirdly if as we know wind turbines can only produce around 30% of plated capacity then when planning the energy infrastructure this can be taken in to account. That’s the argument that the more wind farms you have the more will get generated at those lower wind speeds
    Turning Val's comment - there are some inaccuracies.
    Firstly the kitchen can only produce 3 meals a day and hence (given the figures above) producing one a day on average is ok (that is 30% capacity on average)
    Secondly the farmer will not be equally hungry so on some days he will want a larger meal (high energy demand) and on some days a light one (low energy demand) the kitchen has variable output and there will be days its output will be matched to his hunger.
    Next door to said local restaurant there will probably be a fast burger and chip joint - same quality food but can produce it really quick when asked. The burgers are probably cheaper too but they create a smelly environment.
    So the farmer will always get fed - some days on fine food from the local restaurant (in varying amounts depending on his hunger) and from the fast burger joint on other days. On some days he might need to get a bag of chips to supplement his meal as he wanted a large meal but only a small one was on offer.
    On days the restaurant over produces then they can offer the food to those in the burger joint (read interconnector)
    The argument we should all be having is about what is the objective of the wind farm program - and this is often lost in the emotive arguments of their presence on the landscape.
    Is it:
    1 - to reduce fossil fuel imports - wind defiantly unarguably does that when it comes to electricity generation
    2 - to reduce CO2 output - again unarguable CO2 at the point of generation is zero at a wind farm so wind farms will reduce CO2
    3 - to keep a low stable cost for electricity generation - this is a more complex argument. Wind is zero marginal cost at the point of generation and will remain so for ever (excluding maintenance costs but these are present on all generator) but today and may be for some time into the future fossil fuel will be cheaper - and may stay so - but do you want to eat burgers all your life or do you want to also eat in that local restaurant

    1. I would implore anyone who believes wind energy really does reduce CO2/fuel imports to look at the diagram on this article :

      In 2013 we had 11% drop in CO2 emissions for electricity. But there were 5 diff factors which led to this, the largest been the new interconnector.

      Unquestionably, wind does lead to inefficiencies in the runnning of gas/coal power stations and this will increase in the next few years. Also, you need to account for the increased need for fast acting inefficient generation - DSUs, ocgts and offline diesel etc.

      The best analogy for wind gen is a man with a shop with 5 employees. He is forced by the govt to hire 2 more but the extra 2 are free to come to work whenever they wish - 2am, 4pm, 9am, 1am and whatever days they wish. But the rule is that they must turn up on average 30% of the time.

      Most readers will notice the obvious problems this will cause. Less obvious ones would be 2 cashiers on the same till, both staff will work inefficiently as they will get in each others way also it would be wasteful from a cost point of view.

  3. I fail to follow the points made by Francis. The later article published here by Dr Fred Udo may help. The entire point of my contribution and my videos "valmartinireland you tube" is to show that you cannot count the contribution of wind as its production. The value in money and saleable objects is created by its scarcity which is a function of demand being higher than supply. The value of electricity is that it is demanded per customer requirements and not by producers requirement for a market. Electricity is required constantly in varying amounts. Wind is supplied outside the time demanded and in amounts above and below amounts demanded. That type of electricity is valueless and must be backed up by fossil fuel supply forced to cycle with the weather.. The other point is that a farmer receiving 200 dinners on the 4th January, means 198 will rot. I cover the macro situation in my video No 5 on the Danish Experience and Germany corroborates this as the more wind it installs the higher its co2 emissions become. This is counter-intuitive as most scientific discoveries are. If they were not, they would have been discovered long ago.