Living in Australia? Then You’re Being Powered By Coal – So Deal With It!

If you’re reading this post in Australia, you’re doing so thanks to coal-fired power. Don’t like it? Then get off the internet.

And, while you’re at it, turn off your lights, your air-conditioner, let your smart phone run flat and, just for laughs, start tackling busy intersections without the benefit of traffic lights. Wind ‘powered’ South Australians are masters at it.

The reason that renewable energy zealots and their propagandists have been so successful, to date, is that Joe public has no idea how electricity is generated, and no idea where it really comes from.

On a frosty, dead calm morning in June every last watt and amp being generated comes from coal, gas and hydro, in that order. With that lucky old Sun yet to bob over the horizon and barely a zephyr to be had, around 85% of the electricity that finds its way Australia’s Eastern Grid is coming from coal-fired power, the balance from gas and hydro – and none at all from that endless sea of shiny solar panels and hundreds of slacking windmills.

One line that the propagandist for the wind industry used to run was that, if you spread enough wind turbines out across the country, you’ll always have plenty of wind power, because the wind is always blowing somewhere.

Graphics like the one above – care of Aneroid Energy – depicting the output of every wind turbine connected to the Eastern Grid (1,800 of them, spread out across four states, with a notional capacity of 5,000 MW) during June put paid to that.

Undaunted, the likes of ruin-economy invented a new series of myths, claiming that coal-fired power is ‘unreliable’. Of course, what’s depicted above would never be seen as ‘unreliable’, to the true believer.

Extending the same line of nonsense, ruin-economy conjured up a story about coal-fired power not being ‘dispatchable’. Until now, the term ‘dispatchable’ included the notion that the operator of the power generation source in question was able to control any increase in output and match it to any increase in demand. Not so, according the the wind and sun cult.

Roger Andrews smashes yet another renewable energy fiction and brings us back to the hard-coal reality.

The myth of non-dispatchable coal
Energy Matters
Roger Andrews
6 September 2018

An article from Reneweconomy linked to in Blowout Week 243 made the following claim:

This article acknowledges that we need genuinely dispatchable power stations to complement the growing capacity of variable renewable energy power stations (wind and solar PV) and argues that these can be provided by renewable energy technologies. It shows that coal and other baseload power stations cannot fill that role.

Normally I allow claims like this to pass without comment, but these are so far out of line with what the data show that I decided the Reneweconomy article deserved a post of its own.

The article was authored by Dr. Mark Diesendorf, an Australian academic and environmentalist who according to Wikipedia is a founding director of the Institute for Sustainable Futures at the University of Technology, Sydney and who has at various times also been the Secretary of the Society for Social Responsibility in Science, President of the Australia New Zealand Society for Ecological Economics, co-founder and Vice-President of the Sustainable Energy Industries Council of Australia and co-founder and President of the Australasian Wind Energy Association.

It’s unlikely that anyone with a record like this would have anything bad to say about renewable energy or anything good to say about fossil fuels, but classifying renewables as dispatchable and coal as non-dispatchable is g0ing a little far.

The grid data show that coal functions successfully both as baseload and load-following capacity in Australia (and elsewhere) and also that a large fraction of Australia’s load-following requirements are in fact handled by coal, and effectively none by wind and solar.

So let us now check some Australian grid data. The data are the 5-minute state-by-state data from my initial look at the Australian electricity grid data post. They cover a period of only 19.5 days between July 27 and August 16, 2017 and show generation rather than consumption, which explains the raggedness of the generation plots in states such as Victoria, where appreciable amounts of power are shipped across the state line through interconnectors. The data for Western Australia show that coal contributes both baseload and load-following generation but are not amenable to a quantitative assessment. The data for New South Wales and Queensland, however, are. South Australia and Tasmania have no coal generation and are not considered.

We begin with Victoria, the only state where coal – in this case brown coal – was used as baseload generation and did not contribute appreciably to load-following over the period considered. Partly this is because brown coal (lignite) plants are significantly less flexible than hard coal plants and partly because enough Tasmanian hydro and in-state gas-fired generation is available to fill in the gaps when the wind dies and the sun sets. Generation by source for Victoria is shown in Figure 1:

Figure 1: Victoria generation by source, 5-minute
data, July 27 – August 16, 2017

 

These results, however, support only the first of Dr. Diesendorf’s claims. What of the second; that renewable energy is dispatchable? Figure 2 gives details for Victoria. The top of the pink-shaded areas shows the generation that remains after brown coal generation is subtracted from total generation. It defines the amount of generation that must be handled by load-following sources. The green-shaded area shows generation from renewable sources, which are dominantly wind and solar. It’s uncorrelated with the pink-shaded load-following requirement (R squared = 0.01) and does little or nothing to reduce it. Clearly renewable energy is not a viable load-following source in Victoria:

Figure 2: Load-following generation after removal of brown coal baseload generation vs. wind & solar generation, Victoria. Note the ~100 GWh shortfall in wind & solar generation between July 30 and August 4.

 

In Western Australia black coal supplied both baseload and load-following generation. Estimating how much coal contributed to load-following, however, is problematic. As shown in Figure 2, it contributed much more to load following at the beginning and end of the period than it did in the middle (Figure 3). But a contribution it undoubtedly made:

Figure 3: Western Australia generation by source,
5-minute data, July 27 – August 16, 2017

 

And what about renewables? Figure 4 plots the Figure 2 data for Western Australia. There is again no correlation (R squared = 0.00) between wind + solar and the load-following requirement, meaning that renewables are of little or no use for load-following in Western Australia either. (Note that the level of correlation remains the same regardless of amplitude. Scaling wind and solar generation up by a factor of ten would still return R squared = 0.00):

Figure 4: Load-following generation after removal of black coal
baseload vs. wind & solar generation, Western Australia

 

Now on to the two states where generation is dominated by black coal. First Queensland (Figure 5):

Figure 5: Queensland generation by source,
5-minute data, July 27 – August 16, 2017

 

87% of Queensland’s total generation came from black coal, and in this case it’s possible to make a quantitative estimate of how much of Queensland’s load-following generation came from black coal. To do this I first defined how much of Queensland’s generation was baseload, which I did by setting baseload thresholds at the minimum levels of generation recorded, which were 4,977MW in the case of black coal and 264MW in the case of gas. I then assumed that any coal and gas generation that exceeded these thresholds was used for load-following. Total load-following generation is plotted in Figure 6, once again with renewable generation (all solar; Queensland reports zero wind) superimposed:

Figure 6: Load-following generation after removal of
coal/gas baseload vs. wind & solar generation, Queensland

 

In this case there is a weak correlation between renewables and load-following requirements (R squared = 0.20) because the solar spike coincides broadly with the daytime demand peak. Otherwise solar has no load-following capability and so is again excluded from the list of load-following options.

Figure 7 shows the percentages of Queensland’s load-following generation requirements that were filled by black coal, gas and hydro. Hydro contributed 3%, gas 18% and black coal 79%.

Figure 7: Contribution of generation sources
to load-following generation, Queensland

 

Next New South Wales, where 85% of total generation over the period considered came from black coal. Here are the Queensland figures replotted using New South Wales data:

Figure 8: New South Wales generation by source,
5-minute data, July 27 – August 16, 2017

Figure 9: Load-following generation after removal of coal/gas baseload vs. wind & solar generation, New South Wales. The baseload threshold for black coal is 4,081 MW; there was no baseload gas generation. Note that with the addition of wind the weak correlation caused by the solar peaks in Queensland (Figure 6) disappears. The R squared value is now 0.00

Figure 10: Contribution of generation sources to load-following generation, New South Wales. Gas contributes 8%, hydro 9% and black coal 83%

 

Here we have a suite of graphs which confirm beyond any doubt that black coal in Australia is dispatchable – and evidently capable of ramping up and down at rates high enough to keep the lights on – while intermittent renewables generation isn’t. This is the exact opposite of what Dr. Diesendorf claims in the Reneweconomy article. He does, however, argue that intermittent energy can be converted into dispatchable form through “A mix of several types of responder with different response times”. Specifically:

Demand response is a fast and flexible first responder, but can only last for about an hour. Batteries too are excellent first responders, but on their own are (and will be for several years) too expensive to provide energy for many hours.

Concentrated solar thermal can respond promptly and run for several hours to overnight, provided its thermal storage has been charged up on a sunny day. Off-river pumped hydro (ORPH) with small upper dams can respond quickly and run for several hours to a day or so.

OCGTs and diesels are slower responders, but can operate for up to several days before fuel costs become limiting. ORPH could replace OCGTs and diesels entirely if environmentally sound dam sites with medium storage capacity were found and became part of the mix.

When demand is lower than supply, the outputs of wind and solar PV can be reduced rapidly to restore balance. In other words, wind and PV are ‘dispatchable downwards’.

Also, if the need for future temporary supply (e.g. from a spike in demand) can be predicted while wind and solar farms are operating, their outputs can be reduced shortly before the expected spike and then increased rapidly for a brief period during the spike, to help buy time for other dispatchable responders to come on-line.

It seems that Dr. Diesendorf has only a limited grasp of what it will take to make wind & solar dispatchable. (I particularly like the bit about PV being “dispatchable downwards”. How does this work at night?)

The question that remains is how Dr. Diesendorf can make claims that conflict so violently with the facts. I’ll leave the answer up to the judgement of the reader.
Energy Matters

Here’s where your power really comes from: now, enjoy it!

About stopthesethings

We are a group of citizens concerned about the rapid spread of industrial wind power generation installations across Australia.

Comments

  1. Craig Lucanus says:

    How OCGT’s and diesel turbines make renewables ‘dispatchable’ is beyond me. The only way they can be reliably become so is when the storage issue is dealt with. Without some miracle breakthrough on this, the viability of current solutions doesn’t stack up, though they may be technically feasible according to the laws of physics. Consumer affordability and Australia’s competitiveness must be addressed in viability criteria.

  2. Australia is currently on course to become South East Asia’s largest offshore wind farm. Closely following mainland Europe’s biggest offshore wind farm, Great Britain!

    However, current turbines are massive. Is this the future we really want for Australia?

    As for the ABC and gender quotas. Both the ABC and BBC should look closer to home to the mess that was created when production was outsourced during the early 2000’s. This has created a world of media freelancers who have little or no workers rights. Some of these media companies are nothing more than sweatshops.

    Time to look closer to home before preaching to others.

  3. Why do your graphs differ from those published by the AEMO?

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