Trends in wind output (tips to help you make your entry)

Wind sometimes blows, and sometimes does not.

Over a number of years, we have posted a number of articles analysing wind farm output, and particularly looking into wind diversity as a greater number of wind farms have come online.  The RET is a volume-based incentive (i.e. MWh not MW) so thoughts of capacity remain the domain of the broader NEM, rather than a question tied up within the (still very topical) Mandatory Renewable Energy Target.

Our interest win how wind output is trending has increased further as a result of us linking our BBQ give-away competition this summer to the peak aggregate wind farm output across the NEMPerhaps you’d also like to email in your entry to have a chance to win?

To give everyone a starting chance of winning their new portable BBQ this summer, we powered up NEM-Review and generated this trend of aggregate output (max, min and average) of wind farms across the NEM:


For those wishing to have a chance to win one of 7 BBQs we’re giving away this summer, the chart above will provide some hints about where the peak Aggregate Wind Farm Output will be expected to land for the Extended Summer Period (1st Dec 2014 to 31st March 2015).

(a)  From the perspective of the RET, the trended average output line is most important

(b)  For those wanting to win the BBQ, the peak output is the one to watch (see here for more details).

More analysis about all three green lines will be posted on WattClarity, as we have time this summer.

About the Author

Paul McArdle
One of three founders of Global-Roam back in 2000, Paul has been CEO of the company since that time. As an author on WattClarity, Paul's focus has been to help make the electricity market more understandable.

14 Comments on "Trends in wind output (tips to help you make your entry)"

  1. How effective is wind energy at saving CO2 emissions?

    What’s the abatement cost ($/tonne)?

    • A topic for another post perhaps one day, Peter

    • Hi Peter,
      It depends on the state. The worst case is QLD with 0.92 t/MWh (due to modern black coal plant). At the current LGC price of $33 that’s $35.87/t.
      QLD doesn’t have much wind though so a better representation would be SA or VIC with abatement costs of $34.73/t and $33.67/t respectively.
      The displacement calculations assume that wind displaces the marginal unit (but not hydro units as they can hold their water until later).

      • Tom,

        Thanks you. Can you give me a link to where the methodology for those calculations is documented?

        • Hi Peter,
          I took the marginal unit per 5 minute from AEMO’s NEMPriceSetter.xml files.
          My assumption is that if you added 1 MW of wind at any point in time that you displace some typical unit. The abatement effectiveness is based on the t/MWh from ACIL Tasman’s 2009 paper, this is weighted by the frequency that each unit sets price. This method isn’t great but it is more representative than using local generation as the smaller states are strongly affected by VIC and/or NSW generation. The result is that if you add renewable generation anywhere in the NEM you are most likely going to displace a NSW black coal generator.
          I reweighted the values to remove hydro as that energy can be used later to displace fossil generation. Must-run hydro doesn’t set price and can’t be displaced. If wind was the marginal unit then the addition of more wind power abates nothing; that energy isn’t stored.
          OK, so how do you know I’m not completely full of **it? Since 2010 gas generation dropped only 2% (0.378 TWh). Black and brown coal generation both dropped 20% (31.7 TWh total); mostly because of demand. Wind is up 74% (3.3 TWh). Hydro is ballpark after their run on the carbon tax. The weighted average emissions intensity from the change in coal generation is roughly 1.04 t/MWh. So either my method underestimates wind abatement effectiveness or energy efficiency is better than wind at abating.
          I did this because Grant King kept going ON about how wind displaces CCGT. You’d think the guy would know something about gas generation wouldn’t you?


  2. Tom, Thank you for further explanation. Is the method written up somewhere where I can access it.

    I suspect your assumption about the effectiveness of wind at abating CO2-e is optimistic.

    • ACIL Allen came up with a similar cost of abatement for wind as referenced in pg. 20 of the CCA’s review
      They had a cost of $32 which would suggest that the abatement effectiveness is above 1t/MWh, as the LGC cost has consistently been above this level.
      pg. 166 of the actual report
      Please let me know why you think my estimations are optimistic and what wind would be abating if not coal generation.
      I tried searching for an email address for you but all I got was fashion and publishing businesses. Let me know and I’ll send you an Excel file.

      • Tom,

        “Please let me know why you think my estimations are optimistic and what wind would be abating if not coal generation.”

        Joseph Wheatley (2013) ‘Quantifying CO2 savings from wind power’:
        See the full paper (linked in the post)

        Daniel T. Kaffine, Brannin J. McBee, Jozef Lieskovsky (2013). ‘Emissions Savings from Wind Power Generation in Texas’

        Daniel T. Kaffine, Brannin J. McBee, Jozef Lieskovsky (2012). ‘Emissions savings from wind power generation: Evidence from Texas, California and the Upper Midwest’:

        Herbert Inhaber (2011) ‘Why wind power does not deliver the expected emissions reductions’:
        This paper references many studies into the effectiveness of wind power at reducing GHG emission. All these studies used empirical data. Many studies were not used if they had used data that is not publicly available.

        Could you ask Paul McArdle if he’d mind forwarding your spreadsheet to me.

        • Peter,
          You keep using that Irish source. I get it, if you displace gas the emissions abatement is small. Same thing for CA and TX. We hardly use gas in Australia though.
          Check out the abatement for MISO in the paper you linked – 0.92t/MWh (pg. 7). MISO has a lower proportion of coal generation than the NEM, but like the NEM coal is most commonly the marginal unit. Unlike Ireland, CA, and TX they don’t get half their electricity from gas/nuke. A much closer representation of the NEM.

          • “I get it, if you displace gas the emissions abatement is small. Same thing for CA and TX. We hardly use gas in Australia though.”

            You need to read ans understand the papers.

            Sorry, but I Am not interested in your comments any more. You have no credibility.

          • Seriously, do look at pg. 35 of the econobus link you have above. It has a nice graph of emissions saved by wind vs. coal generation fraction. This would be helpful when comparing between regions.

            Have a nice day,

        • Regarding Inhaber’s paper, his abatement curve uses Germany as the example. Germany’s main priority is prematurely switching off their nuclear fleet, thus emissions from the electricity sector have remained flat as renewables are only keeping up with the reductions in nuclear energy. I would phrase this as keeping emissions from rising while removing nuclear.
          However you phrase it the example does not apply elsewhere as other nuclear fleets are not retiring by force. You should not use his fictional equation for other regions.
          Inhaber also cites de Groot on part load efficiency.
          Total BS.
          80% load, peak efficiency is 35% for subcrit coal.
          50% load, lowest efficiency is 33%.
          100% load is a bit below peak efficiency.
          At worst that’s 5.7% more emissions per MWh but with 37.5% fewer MWh sent out.

          • “Regarding Inhaber’s paper, his abatement curve uses Germany as the example.”

            You should read and understand. You have no credibility.

          • Back up generation just has to be available. It’s not actually generating.
            If a coal plant running at 100% has a SRMC of $35 and sells into NSW at $35 they are breaking even. If the same plant ramps down to 50% but consumes the same amount of fuel they will lose $35 per MWh. This ramping happen to the black coal generators every night. They would go bankrupt very quickly if you were right about backup.
            OR you could suspend disbelief and realise that they just feed less coal in.

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