Ask the Right Question

Yes, wind is cheaper. Provided your expectations are lower.

Well, it makes a great headline.

“Renewable energy now cheaper than new fossil fuels in Australia”

Vive la Revolution! From now on, fossil fuels will not be built, renewables will because they are cheaper! Hurrah!!!

This headline comes from new analysis from research firm Bloomberg New Energy Finance  who have foundelectricity can be supplied from a new wind farm at a cost of AUD 80/MWh (USD 83), compared to AUD 143/MWh from a new coal plant or AUD 116/MWh from a new baseload gas plant”.

This may have caught people by surprise, not just that the wind is cheap(ish) but that the new fossil is costly.

But if you have already spotted the flaw, you get a star. This analysis, and the breathless headline accompanying it, are a great demonstration of how to be correct and irrelevant all at the same time.

These figures compare the cost of electricity production between:

  • Marginal costs of introducing incremental new wind, which will be intermittent with capacity factors around 30%
  • Marginal cost of introducing new modern coal, which would be baseload and quite large, with potential capacity factors above 85%
  • Marginal cost of introducing new baseload gas, which would be combined cycle plant, again quite large, again with potential capacity factors above 85%

All three produce ostensibly the same product (electricity), but they do not provide the same service. A new wind farm, with the well understood intermittency does a poor job of meeting our requirement for baseload, being the minimum electricity demand required at all times.

If you want to compare these sources fairly, you need to set them the same challenge, namely that of providing baseload.

That’s what we did in Zero Carbon Options. The challenge was to replace two small coal plants of 740 MWe in South Australia, with success defined as reliably producing 4,650 GWh per year. We compared a renewable option as proposed by renewable proponents with a nuclear option.

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It is when you ask renewables to respond to this specific challenge that the full story is revealed.

The renewable option could not be wind only, as that fails the reliability test. It was a hybrid proposal of solar thermal with storage (760 MWe) and wind (700 MWe). So that’s 1,460 MWe to replace 740 MWe.

The capital cost is horrendous at over $8 billion, most of which is the solar thermal. The price of electricity is telling: wind cheapest, then nuclear, then miles of daylight, then solar thermal.

The renewable option had 2,810 GWh of the electricity coming from solar thermal at (low estimate) $250 MWh, and 1,840 GWh coming from the wind at (low estimate) $90 MWh. So the average cost of the electricity production was $186 MWh. As you can see, that is way, way higher than either the coal or the gas as priced by Bloomberg.

Even with this, the reliability test was poorly addressed. The level of storage was unspecified, but this solar thermal proposal had a capacity factor of 40%. Two wrongs don’t make a right, and two intermittents don’t make a baseload. To get a higher capacity factor would mean more storage, which would mean more cost.

The bigger you scale this, in trying to replace many different baseload plants in many places, the more the ancillary costs mount, as the ability to move huge quantities of power over great distances becomes critical for reliability and stability.

The nuclear option performed much better, with about half the capital cost, very high capacity factor, no question mark on reliability and electricity for (low estimate) $101 MWh. That is to say nothing of the advantages in lifespan, land use, water security and material consumption.

2x 728 MWe CANDU units from Qinshan, China. Unit 1 went from concrete pouring to criticality in 51.5 months. This could be readily reduced to 48 months with capital costs cut by 25%. Click the image  to read about this
2x 728 MWe CANDU units from Qinshan, China. Unit 1 went from concrete pouring to criticality in 51.5 months. This could be readily reduced to 48 months with capital costs cut by 25%. Click the image to read about this

The point here is not that wind is cheap, expensive, good or bad. It’s that replacing old baseload with new baseload is costly, no matter the tech, but the renewable pathway is most costly of all. If we are serious about replacing our aging fossil baseload with zero-carbon alternatives, then we need all options on the table. If Bloomberg New Energy Finance are serious about informing, not exciting, they will provide a fuller picture next time.

Update: This piece has sparked quite a bit of discussion. Lots of folk seem to want to say I am wrong, or argue that I will be in time. Bloomberg have taken note. Their lead clean energy researcher offered this over Twitter…

BloombergTweet

…which is of course my point. Where is the discussion of the “low pen(etration)” in the article? The price at “low penetration” means the price if we don’t build too much, and don’t try to use it to fill the role currently filled by coal and combined cycle gas. This makes their comparison entirely redundant. So it may be “news for most ppl”, but if we want an intelligent energy conversation then “most ppl” should be given the complete picture.

Try this headline:

“New wind power at low penetrations cheaper than new baseload fossil in Australia”

Subtly different, but now it is actually in context, informative and useful in building understanding of energy.

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