Sunday 3 February 2019

Is Offshore Wind the Answer ?

ESB are planning to develop a massive 330MW wind farm off the east coast of Ireland. Will offshore wind be any different to onshore wind ? The experience in Denmark should be useful. The capacity factor for offshore wind in Denmark is around 43% which means the output will certainly be much greater than onshore wind in Ireland (which has a capacity factor of about 28%). 

But will offshore wind compliment wind energy? If the peaks in offshore wind occurred during the lows in onshore wind, then that would be very useful. This would result in a smoothing out of the intermittent profile of onshore wind we are so familiar with. We could call such a renewable energy source a "complimentary source". 


An example of a strong complimentary source would be perhaps solar energy, where during hot calm conditions such as last summer, solar energy would begin to peak just as wind energy fizzles out. In this case, we could say that solar and wind are negatively correlated, which indicates that they are strong complimentary sources.


To establish whether offshore wind is a strong or weak complimentary source, we can once again look at the data from Denmark, which has about 8GW of offshore wind capacity installed. In 2017, Euan Mearns analysed three years worth of data for both offshore and onshore wind, and found that the two are well-correlated (R squared = 0.71 for hourly data, 1 is a perfect correlation). This means that offshore wind is a relatively weak complimentary source. When the wind is blowing on land, chances are it's also blowing out at sea (and vice versa). 

Hourly onshore (red) and offshore (blue) wind generation with total generation scaled up to meet total demand, Denmark, 2014-2016 (from Euan Mearns).
So this means that power stations will still need to be ramped up and down as before. Offshore wind, like onshore,  will be incapable of replacing power stations, meaning its usefulness will be limited.

References: http://euanmearns.com/can-offshore-wind-be-integrated-with-the-grid/

10 comments:

  1. Another issue that needs to be addressed concerning the expectations of this E.S.B investment. Is the pretty rapid drop in capacity factor experienced in offshore Denmark.
    In a report published in 2012 Dr Gordon Hughes determined that over 10 years the capacity factor dropped from 39% to 15%. To maintain output significant additional capacity would have to added every 3 to 5 years. It is unlikely therefore to useful with an R2 of .71 and rapidly falling capacity factors the only 2 things that are certain is very little extra wind energy and large fiscal losses forth ESB.

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  2. Offshore wind will be more expensive than onshore wind, it will add enormously to electricity costs. Denmark have the highest electricity costs in Europe.

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  3. There are a few points to make on the wind energy load factor issue.

    1) The load factor is the amount of electricity produced in one year expressed in Mega Watt hours (MWh) divided by 8766 multiplied by capacity multiplied by 100 to give a percentage. This must not be confused with total installed capacity, the amount of other generators displaced, or the amount that can be allowed into the grid. Generally (everything else being equal), one 2 MW turbine will have the same load factor as 1,000 X 2 MW turbines. For example a wind farm has a capacity of 10 MW and the electricity generated is 7,400 MWh. 7,400 / (8766 x 10) X 100 = 8.44%.

    2) Professor Gordon Hughes of Edinburgh University carried out a study of factors in the UK (including Northern Ireland) and found factors of 24%. He also found that the factor degraded by 7% over 19 years.

    3) I conducted a study based on a physical examination and referenced Irish weather services data 2071 to 2001 and found an average factor for the Island of Ireland of 24.1%.

    4) Examination of Company accounts show factors ranging from 14% to 27%. Gartnaneanne on an excellent high site bear Bailieboro, Co. Cavan reported a 25% factor for 2016. This facility had 2 gearboxes replaced this year. It involved about 12 workers with two cranes and other equipment for 5 days.

    The best source I can find is DUKES, the Digest of UK Energy Supply https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/736148/DUKES_2018.pdf or search DUKES electricity load factors to find it.

    Go to page 185, (first 2 paragraphs). Note paragraph 2 giving the data before being altered. The on-shore wind factor was 24.2% and the off shore was 36.7%. The on-shore figure is accepted, but the off-shore one is questioned. In his book the Wind Farm Scam, John Etherington found the figure to be 26% for 2006 and blamed a buildup of salt and dead bugs on the blade for the degradation. The only Irish off-shore project is Arklow Bank off the East coast and it reported factors as low as 25%. I messaged DUKES and they confirmed the figure for on-shore wind for 2017 was 24.2%. The higher figures for 2013, 2014, 2015, and 2017 cannot be an accurate reflection of actual load factors. Wind speeds for these years were no different than the others, but it is much harder to analyse off shore than onshore.

    5) An interesting paper on the subject is by Nicolas Boccard which draws attention to my points. I personally questioned on-shore factors published by Eirgrid Plc in 2010 at 32%, it turned out they did not base their forecast on historical data at all. Boccard's paper is an eye opener, particular Table 5 on page 3. It's worth reading https://docs.wind-watch.org/Boccard-Capacity-Factor-Of-Wind.pdf or search Boccard's capacity factors for wind. Note he says an off-shore factor of 43% is required to keep the books in the black. They are not getting that even by DUKES's reporting.

    There are two types of counting, the hopeful type and the historic type. The exposure to a potential miscalculation is very very big.

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    1. Regardless of the correct capacity factor ,the point of the article was to show that offshore wind does not compliment onshore wind very well and will only make the intermittency problem worse .

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  4. The Irish Onshore capacity factor for 2010 was 23.8%. Eirgrid ignored it because it was an outlier. That would never happen again.Smaller wind turbines 22 kilowatt to 110 kilowatt will last about 20 years. As wind turbines increase in size their longevity decreases significantly. These large multi megawatt wind turbines can last as little as 4 years with massive output drops.So when comparing capacity factors in Denmark and the U.K. The population content should be noted. We should from a historical and population perspective ignore the Danish figures.The Danish wind farms were populated with small wind turbines.As they do not reflect what is happening in Ireland and there U.K. Where larger wind turbines predominate. It was also noted in the U.K. that capacity factors in larger wind farms drop as much as 50% every 5 or 6 years.

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  5. The blog is correct in saying off-shore wind does not complement the on-shore variety very well, which effects both the consumer and emissions targets. That does not effect the wind companies who are paid on the load factor. Investors were over optimistic when assessing on-shore wind, the factor is too low to break even, pay interest and repay the capital loan. We now have plenty of information to assess the financial situation of on-wind companies and its not a pretty picture. Getting this information took a lot of work in the face of such fierce opposition from vested interests.

    Other than Arklow Bank, we have little information on Irish off shore wind. We can assume the capital and running costs are much higher and a much higher factor would be needed to cover all costs and leave something for investors. Here is an extract from the Energy Matters web site on UK off-shore factors..
    "The average capacity factor at 28 operating UK offshore wind farms is 33.6% (most recent 12-month average) and 34.5% (lifetime), increasing to 36.1% and 37.5% when four demonstration projects are discarded. There is a dependence of capacity factor on age, with older farms showing capacity factors of around 30% and younger ones factors of around 40%. This is interpreted to be a result of increased turbine sizes, with taller modern turbines accessing higher wind speeds at higher elevations. There is no evidence for significant degradation of turbine performance with time. A “generic” UK offshore wind farm coming on line in 2017 can be assumed to have a capacity factor of around 41%, although projections indicate that the turbines planned for the Hornsea II farm discussed in previous posts could have capacity factors exceeding 60%.


    The data used in this post are from Energy Numbers. I have no way of verifying these data but have assumed them to be correct. "

    This tells us we need to be very skeptical of forecaster factors. They always turn out out be at least one third too high. This begs the question of where will the money come from to keep the companies affloat? We are seeing an ever bloated electricity sector, expanding by the day to its goal of 15,000 MW. This winter weekday morning we are only using 5050 MW which is likely to be winter peak demand. .

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  6. There is plenty of evidence in the Danish Data of of significant performance degradation of wind turbine performance as they age.There can be up to a 40% decline in output in as little as 3 years. A Siemens 3.0 Megawatt 101 meter hub diameter wind turbine lasted only 8 years.You need to be extremely sceptical of claims made by the wind industry.

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  7. Climate change and most forms of renewable energy have been to the forefront of the thoughts of a few campaigners trying to alert the world to what they see as as ill advised hysteria and what I see as a total scam. There has been hysteria before, Hitler was hysterical, there was religious hysteria for a long time. With the new climate and magic renewable cures phenomenon, governments went with the hysterical minority believing voters would follow and convert the world into a green utopia using the weather.

    Of course that is not going to happen for the reasons published here. We conservatives can take heart form the fact that the very institutions of government and the very governments themselves are no longer able to hide from the people. The yellow vest movement in France is a serious threat to green hysterical President Macron who is on 20% in opinion poles. Brexit too is seen as a disaster for green hystericals. Enter president Trump.

    The voters in the USA are going to be faced with two choices in November 2020. There is the Republican Party led by president Trump who needs no introduction and the Democrats with their Green New Deal. Voters have to decide if they want to continue with the economic prosperity and home comforts under Trump or go back to the horse and cart. Of course they will rejects the Democrats in every state. Paddy power Bookmakers is giving 2/1 on a Trump win. It seems like a good investment, but more importantly we will see this green menace forced to face the music and be put to the sword once and for all.

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  8. Saturation point has already been reached.
    There is already far too much 'intermittent', 'unreliable', 'destabilising' renewable wind energy in the energy mix of the electricity system.
    Too much renewable wind energy is destabilising the national electricity grid system so much so that the once previous 'stable' 50Hz grid frequency +/-0.5Hz RoCoF has had to be widened to +/-1Hz by the Commission for Regulation of Utilities CRU, in effect reducing standards to outside what would normally be considered best practice in avoiding the increased risks of damage to electrical equipment, electronic control devices, the tripping of power stations and 'coordinated' outages (load shedding) and full blown outages.
    In effect Ireland's 'Security of Supply' has already been seriously compromised.
    It is totally foolhardy to think that expensive experimental potentially highly hazardous Battery Energy Storage Systems devoid of international recognised safety standards will solve the Grid Frequency Control issues.
    Also it is ironic that this experimental grid frequency control technology is itself highly vulnerable to damage and outages from grid frequency excursions outside the 'safe' limits of 50Hz.
    How long will it be before the CRU will have to seek to further reduce the RoCoF grid frequency standards to say perhaps +/-2Hz?
    Are the CRU in reducing the standards eliminating any liabilities that they may have for what is fast becoming a 'high cost' 'poor service' electricity system?
    Therefore proposals to add offshore wind energy into the energy mix is complete and utter madness. It will only compound matters by further destabilising the electricity grid system.
    And it is a nonsense to say that offshore wind energy will be exported via interconnectors to say the U.K. or mainland Europe when they also already have enough renewable energy in their energy mix.
    Plus Electricity Interconnectors are extremely expensive and unreliable. One only has to look at the lengthy outages of the Moyle Interconnector and the Interconnector between the UK and France for evidence of this.

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  9. The current cost overruns of the National Children's Hospital will pale into insignificance compared to the cost of renewable electricity supports, costs of energy infrastructure and experimental ancillary services to support the renewable energy industry, costs of Smart Meters, costs of electricity supports required for Battery Energy Storage Systems BESS's, the increased installation of banks of diesel/dual fuel generators (Demand Side Units DSU's/Electricity Exchange services), Electricity Supports and 'critical infrastructure' required for Data Centre Industry even perhaps the proposed €1Bn Celtic Interconnector currently being fast tracked, the costs in general of the development and operation of Electricity Interconnectors and the costs of the largely unregulated Renewable Electricity Certificates and Carbon Trading Markets.

    Just as the cost overrun on the National Children's Hospital has resulted in other health projects now having to be shelved likewise the burden of the costs of flawed renewable energy policy is already having and will continue to have serious negative socioeconomic and environmental consequences.
    When people wake up to the amounts of money that have been invested in the 'transformation' of a once stable, reliable, secure electricity system into an extremely 'high cost' 'poor service' electricity system they will be utterly flabbergasted.
    That money could have been better spent on insulating homes, providing homes, reducing homelessness, tackling the hospital trolley crisis, paying nurses a decent wage etc., and all the while leaving our former stable electricity system fully intact.
    What an unnecessary impoverishment of a Nation to date via a largely silent 'electricity grid warfare'!

    Ancillary Smart Meters and Battery Energy Storage Systems are likely to fail as experimental measures to try stabilise grid frequency.
    Therefore increases in 'coordinated' outages and full blown outages are more than likely on the cards.
    Is it any wonder that the European Commission has requested EU Member State Electricity Blackout Preparedness Plans?
    Electricity Blackouts and State Member Risk Preparedness Plans (22nd November 2018)
    http://europa.eu/rapid/press-release_STATEMENT-18-6533_en.html

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