Wind energy hits 100% of South Australia demand on Sunday

South Australia’s energy market continues to provide fascinating viewing for energy nerds, large energy consumers and vested interests since the exit of the last coal-fired generator just over a fortnight ago.

On Sunday, wind energy exceeded local demand for more than 10 hours, from 1.40am to just before midday (11.55am), with a peak of 120 per cent of demand at 4.30am. (See graph below, courtesy of Melbourne Energy Institute).

sosuth australia wind demand

Of course, this does not suggest that wind energy is about to provide 100 per cent of the state’s energy needs all the time, or even average out over the whole year.

That level currently stands at around 40 per cent, but it does highlight the possibilities, particularly with more wind energy projects in the pipeline that could more than double the current capacity, and push for the need for more inter-connectors to other states.

And the wind supply – while predictable – is variable.

As this graph below illustrates, while South Australia has enjoyed reasonably strong wind conditions over the past two weeks, its 1,500MW of wind capacity contributed little on Friday, resulting in more than 1,000MW of gas-fired generation for a time, and for prices to shoot skywards.

sa may 2016

 

Indeed, one of the things to watch in South Australia is the movement of wholesale prices. South Australia has the most volatile prices, partly because no other state has such big swings in demand, and because it has just a few dispatchable generators serving the market, which is more than two-thirds supplied by two players.

South Australia has historically had the highest prices in Australia, thanks to that volatility, and it’s reliant on expensive gas. So what’s interesting to watch is the comparison between South Australia and Queensland, the other state most reliant on gas as the marginal cost of generation.

While gas is used to fill in the gaps between wind and solar in South Australia, it is used in Queensland to fill the gaps between the output of coal and system demand, minus the input of 1.5GW of rooftop solar. Queensland, apart from a few biomass power plants, has no large-scale renewable energy generation.

In the past two weeks, South Australia’s average daily price has been cheaper than Queensland’s on eight days out of 14. These next graphs give a different view.

Those days mostly correspond with low wind days (see graph below) – May 13, 17, 18, 19, and 20. On the days with lots of wind, the South Australian price is often well below that of Queensland.

sa may block 2016

 

This next graph should be viewed in comparison with the one above. This one shows the average daily energy supply in 2015. The white space below the green represent imports from Victoria. It seems that South Australia, even with the local brown coal generators switched off, is importing less than it did at the same time last year.

sa block may 2015

Note: Thanks to Melbourne Energy Institute for the graphs, sourced from NEM data.


Comments

14 responses to “Wind energy hits 100% of South Australia demand on Sunday”

  1. Zvyozdochka Avatar
    Zvyozdochka

    I enjoy seeing a demand graph, to remind the baseloaders that demand is not smooth and *something* fills the gap.

    Rather than calling responsive tech ‘backup’ or ‘peaking’ we could call it ‘top-up’ (from supply to demand).

    Then the purpose of the renewable system is to tune out the ‘top-up’.

    1. Andrew Woodroffe Avatar
      Andrew Woodroffe

      And once output exceeds load, the windfarms can then spill to offer load following services as well. And once battery storage gets to a certain point, it will be goodbye to spinning reserve.

    2. Jan Veselý Avatar
      Jan Veselý

      Residual load

  2. Mark Roest Avatar
    Mark Roest

    Battery storage is getting cheaper, and can fill in the gaps in a modular, almost infinitely extensible way, as well as storing any excess not sold to another customer.
    With lots of data tracking to establish relationships among weather, user patterns, and renewable energy supplies, it is possible to spin up a gas generator when a shortfall is expected — using it to top up the distributed renewable energy system when it is unable to meet the load. That will become an increasingly rare event, as the market, and financing, open up for renewable energy conversion into electricity and its storage in bulk, which then become as ubiquitous as the ultimate sources are.

    1. solarguy Avatar
      solarguy

      Yep and the best way to power those gas turbines is with methane from shit. No I’m not joking. Over a months supply of shit produced methane can do the job.

      1. Alan S Avatar
        Alan S

        You can visit Bolivar treatment plant which I’m doing tomorrow to see digestors and generators in action. However the quantity of methane generated appears to be no more than is required to power the plant.

        1. solarguy Avatar
          solarguy

          I think you will find their using the gas to power the plant as designed. If they were to store the gas and use it when needed in times of low solar it would do the job for the local grid. Of course they can add other feed stock as well.

      2. Mark Roest Avatar
        Mark Roest

        Solarguy, you are spot-on.
        I was in a startup company planning to do methane from hog farms. We found that the best digester technology in the world comes from two brothers in (I think Provo), Utah, also professors at the university. Fully-automated and instrumented, 25,000 gallon tanks, relatively tall and narrow, with a 4-day transit time average; you can control the proportions of bedding material vs methane you get out at the end by changing the transit time. No Sulfides, no gravel clogging, remotely monitored by them. Very high yields meant relatively short payback; less than 3 years if I remember correctly. It’s relative to the cost of power or fuel in that locality.

        1. solarguy Avatar
          solarguy

          Thanks for the confirmation Mark. Cheers!

    2. Andrew Woodroffe Avatar
      Andrew Woodroffe

      We know from modelling over here in WA, that there will be times when there will be insufficient wind and solar for the load even with very large amounts of wind and solar, say 5 x the current levels. And that even with shiploads of battery storage, there will be a dozen or so times a year when top up from other sources will be required for a few hours. Our current gas turbine fleet of some 3500MW would suffice, just that their role will gradually change over time from primary electricity generator to very occasional topup.

      1. Mark Roest Avatar
        Mark Roest

        Well, that’s a very good change!

  3. lin Avatar
    lin

    When commenting to the family about the beauty of the wind/demand graph, my daughter suggested a beautiful wind turbines from around the world calendar as a fundraiser, and to point out to some of our less aesthetic politicians what arsehats they are.

    1. Andrew Woodroffe Avatar
      Andrew Woodroffe

      This is already done by turbine manufacturers. We get our Enercon calendar every year for the Mt Barker and Denmark windfarms. Nevertheless, it is excellent idea and it would be great to have a calendar featuring Aussie projects.

      1. solarguy Avatar
        solarguy

        Sure beats the shit out of a coal fired smoke stack don’t it!

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