Anti-renewables bingo during the upcoming heatwave

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As temperatures soar and households turn on the air-con, it’s a critical time for Australia’s network operator – and for critics of renewable energy.

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It’s going to be an exceedingly hot week in South-Eastern Australia. Not as hot as a couple of weeks ago, which the Bureau of Meteorology labelled ‘one of Australia’s most significant’. During this week, Victoria experienced its hottest four-day period on record.

From the Bureau’s Special Climate Statements

As heat soars, so will electrical demand, as domestic consumers turn on their air-conditioning units. It’ll be a critical time for the national market operator, AEMO. It’ll also be a critical time for critics of renewable energy. Times of need are, I suspect, times at which deception is easiest, and most readily consumed.

By taking the normal operation of renewable energy sources, and painting this as some sort of ‘failure’, the critics of renewable energy will avoid having to use logic in their polemics.

In a previous post, I explored the mechanics of this spin in a bit more detail. Since the first heatwave, there have been a few more attempts to label the normal operation of variable fuel types as some type of ‘failure’. They’ll show up again this week, so here’s my handy, quick-reference guide to the tactics you’ll see deployed by critics of renewable energy, and the logical fallacies they’re plugged in to.

Intentional Focus on a Small Time Period

Wind generation is variable; as wind speeds vary, so does the output of wind farms across the National Electricity Market (NEM). The fact that wind speeds are sometimes high and sometimes low will be proffered as some sort of analytical revelation, brought to the masses by merciless scientific analysis. From the first heatwave comes an example, from The Australian’s Environment Editor, Graham Lloyd:

Critics will point to periods when the combined generation output of wind farms is low, and offer this as proof of ‘failure’. This decrease in output is easily forecast. Sometimes, wind generates a lot, reducing our need for fossil fuels. Other times, it generates less. This is precisely what we expect, and by painting it as some sort of malfunction, anti-renewable writers will be hoping you quickly forget about the actual quantity of energy contributed to the electricity market from renewable sources – take South Australia’s fuel-mix, for instance:

You’ll see short periods of low generation labelled as a failure, without an explanation of what ‘success’ would look like (presumably, the generation of wind energy without the movement of wind). It’s a logical fallacy we shouldn’t forgive.

Assumption that the Electricity Market Doesn’t Exist

“If we’d been relying on wind farms, we would have had multiple blackouts and hundreds, if not thousands of extra deaths” wrote Terry McCrann, in an article for the Herald Sun. Wind energy is one fuel source on a diversified energy system. We use coal, gas, hydro, wind and solar to source electrons. Quite simply, the more energy we source from renewable sources, the less we need to burn coal.

A grid comprised purely of wind exists only in the dark recesses of the minds of those opposed to renewable energy. An allergy to nuance drives this fictional sole-technology scenario, the basis of McCrann’s horrible visage, of thousands of deaths due to a single, sinister technology.

Out of curiosity, I had a look at how many domestic air-conditioners could have been powered by the output of wind farms, on a five-minute basis, over the course of the heatwave (a domestic air-con uses ~3.08 kilowatts):

At its minimum output, the output of wind farms could still have powered 29,865  air-conditioners. This week, you’ll hear people criticising wind, predicated on the assumption that no other generator on the electricity market exists. It’s surreal, absurd and wrong.

The Myth of Extra ‘Spinning Reserve’

The fact that wind energy often crowds out fossil-fuel generation is a tricky fact to reconcile with the narrative of inefficacy pushed strongly by critics of renewable energy. South Australia’s emissions intensity has been steadily reducing as wind energy begins to comprise a larger percentage of electrical energy in the state:

A mix of reduced demand and increased renewable penetration has led to SA’s emissions being down by a third since 2005

To counter this fact, there’s a curious little myth that seems utterly invulnerable to contact with reality. It’s centered around the concept that even when wind farms are generating electricity, coal and gas fired power stations are, somehow, continually using fuel, as they’re being used as ‘spinning reserve’ – and so, renewable sources provide zero reduction in NEM-wide carbon emissions.

McCrann invokes it in the last line of his opinion piece: “You have to keep extra coal-fired – or gas – stations ticking over, literally 24/7, to be able to supply power when..the wind don’t (so often) blow”

There’s already some degree of ‘spinning reserve’ built into the NEM – wind requires no extra, and this ‘spinning reserve’ is a key component of any energy system, regardless of the penetration of renewable energy. As stated in “GHG [Green House Gas] and Cost Implications of Spinning Reserve for High Penetration Renewables, Technical Assessment Report 73 – March 2008” from the CRC for Coal in Sustainable Development:

“The often held view that operating larger fossil plants at part load to provide spinning reserve would negate the greenhouse gas emission benefits of wind is false”

And, you can read more about an NREL study into the issue here. So, when someone tells you, this coming week, that mysterious, non-specified generators were pumping out carbon despite not generating electricity, think closely on the logic of their claims, and whether they’ve produced evidence, in the first instance, to support their claim.

The Usage of Really, Really, Really, Really Bad Graphics

This image, again from McCrann’s article, uses a tactic that I suspect we’ll be seeing again, in the near future:

There’s a few wonderful little components of this attempt to present and explain generation data, that I found amusing. Most obvious is the fact that McCrann chose the day with the lowest quantity of wind generation, and made that chart the biggest. It’s clearer when you look at the total energy over the five days – note that the two hottest days are the ones with, by far, the most wind generation:

Another trick is making the (unlabelled) y-axes on differing scales – masking the significant increase in generation that occurred over Thursday and Friday. Confusingly, the chart on the far left seems to have been denied its full axis entirely.

Pointing out that the wind turbine used as the background is actually from Hawaii, not Australia, is an afterthought, at best.

We’ll see chart-crimes committed in the name of the invocation of fear around renewable energy. Forget the mechanics of an emotional response to an illogical argument – think about how wind actually operates on the National Electricity Market. You don’t need to quake in fear, this week.

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It’s odd how predictable these things are. As the penetration of renewable energy increases in the grid, we’ll continue to see criticism because renewables haven’t instantaneously resulted in the immediate decommissioning of all fossil fuel powered stations. We’ll also see continued efforts to distract from the fact that these machines are designed to provide energy, not power. Alone, they can’t service the entire energy market, but in a diversified energy system, they’re already chipping away at our addiction to fossil fuels.

At the time of writing (08:15 AEST 28/01/2014), wind is providing 40% of South Australia’s total generation mix – today, Adelaide maximum temperature is forecast to be 43 degrees celsius:

At times, this will be higher, and at other times, this will be lower. But there’s no escaping the fact that renewable energy sources are behaving exactly as we expect them to. If anyone tries to tell you otherwise, take some time to tease apart the logic of their claims – It’s likely you’ll find a gaping void.

This article was originally published on Ketan Joshi’s blog, Some Air. Reproduced with permission

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11 Comments
  1. Chris Fraser 6 years ago

    Good thesis … and I have another bone to pick with the negators …
    They have only picked on wind in isolation, and mostly forgotten about the contribution of all the other renewables. Especially PV, which arguably has a profile well matched with the load during heatwaves. We just can’t get enough of it.

    • Arkose 6 years ago

      you do realise PV systems dramatically reduce output after 35C

      • juxx0r 6 years ago

        Data or it didn’t happen.

        • Arkose 6 years ago

          ring the sales office for PV and ask the question like i have. By 42C they are down by 30%

          • Chris Fraser 6 years ago

            Darn, Arkose, you’re probably right … ;). Maybe better to sit in my armchair and ponder doing nothing.

          • juxx0r 6 years ago

            A good solar module will do 0.5% loss per degree over 25 degrees, what you’ve quoted is a particularly bad module at over 1.5% per degree.

            “If you look at the manufacturer’s data sheet you will see a term called “temperature coefficient Pmax”. For example the temperature coefficient of a Suntech 190 W (monocrystalline) solar panel is –0.48%. What this means is that for each degree over 25˚C … the maximum power of the panel is reduced by 0.48%.

            So on a hot day in the summer – where solar panel temperature on the roof might reach 45˚C or so – the amount of electricity would be 10% lower.”

            Also you’ve only got half the picture. What you’ve been told is measured at 1000W/m2, under the conditions you’re talking about the irradiance in SA and Victoria could be up to 1200W/m2. So even though you might have dropped 20% efficiency, you’ve got 20% more sunshine.

            See the attached chart.

            Also check out http://pv-map.apvi.org.au and you’ll see that in the height of the heatwave, SA produced almost 300MW and Victoria, 350MW.

          • Goldie444 6 years ago

            30% down? Sure as PV panels got hotter after about 28C to 30C and up to 43C they will generate less Kwhs.
            But here is some data from my system (2.5kw 2 arays 2 inverters 14 panels @ Bendigo Vic) over the hot week:
            2014-01-11 15.68 hot day 36
            2014-01-12 16.96 hot day 36
            2014-01-13 16.03 hot day 39
            2014-01-14 15.06 hot day 44
            2014-01-15 13.68 hot day 43
            2014-01-16 14.18 hot day 44
            2014-01-17 14.3 hot day but cloudy 44
            2014-01-18 10.5 hot day 38 and cloudy

            This does not show a 30% drop off.
            My best day in the last 3 months was 17.7 kwh on 25 Nov 2013.
            My worst day was 2.03 kwh which was 100% cloud all day with some rain.

      • Gordon 6 years ago

        >>PV systems dramatically reduce output after 35C
        No they
        don’t, it’s a linear reduction in output, a small percentage reduction
        of output per degree of cell temperature, which varies according the the
        particular variety of panel. There’s nothing magic about 35C, PV still
        produces power on the hottest of days. Panels typically operate at 20-30C above ambient anyway.
        Big nuclear power stations have had to shut down completely in the US when the cooling water became too hot. I’d call that F for Fail.

    • Ketan Joshi 6 years ago

      Yeah, something I hope to cover in the future. I suppose it’s worth keeping mind relative quantities, too. Giles has linked to a great live solar PV site in the past – shows the data quite well:

      https://reneweconomy.com.au/2013/australias-astounding-solar-pv-contribution-now-live-91543

      Remember temps today in SA were quite high – might be relevant to your discussion below?

  2. Arkose 6 years ago

    Wow the accuracy of figures being provided to 2 Decimal points seems bizarre for real world scenarios. I am buying PV system and only just being made aware of limitations due to temp like wind generators to wind velocity and nuclear power stations apparently shut down by heat.
    Yes solar panels a and wind and nuclear are all excellent power sources for the present and future generation of ever increasing electrical requirements
    Limitations need to be highlighted as well as benefits

    • juxx0r 6 years ago

      If you’re that worried about it, get CdTe panels which have a much lower temperature coefficient

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