Antinuclear

Australian news, and some related international items

Coal not likely to benefit from Turnbull’s new energy plan

But here’s the real kicker: all currently available information suggests that the “reliability obligation” will all but explicitly rule out coal.

The Energy Security Board’s letter to the government says the reliability obligation will require retailers to buy a minimum amount of “flexible dispatchable capacity”. But most coal power plants are very inflexible – unable to turn on or off quickly

Why Turnbull’s new energy plan may not be so good for coal –  explainerGuardian, Michael Slezak, 21 Oct 17

There is very little reason to think that coal will benefit from the reliability guarantee in the government’s national policy, 
The prime minister, Malcolm Turnbull, has no doubt been selling his new national energy guarantee to many of his colleagues by arguing it will be good for coal power.

Green groups are protesting the policy on the same basis, calling it a “dirty energy target”.

Even Origin Energy has told its shareholders that the Neg means it might need to keep the largest coal-fired power station in Australia open for longer.

The basic idea is that alongside the “emissions guarantee” there will a “reliability guarantee”. Retailers will be forced to buy power that has a relatively low emissions profile, but also buy enough “reliable power” so that they can keep the lights on.

And almost everyone is assuming that reliability guarantee will subsidise coal (as well as gas and and other dispatchable generators).

But looking at the information available – with the very big caveat that there is not much information available – there is very little reason to think that coal will benefit from the reliability guarantee.

There are two big reasons to be sceptical.

First, coal is just not particularly reliable. In fact, the security of the entire grid is designed around the possibility of a large coal generator dropping out unexpectedly – which they regularly do.

Second, all indications are that the reliability guarantee will just be regulation of the existing capacity market, where retailers pay dispatchable generators to be on standby in case they need them. And coal very rarely is able to sell those contracts.

Coal is just not that reliable

Among the various generator types, coal is the biggest security threat to the grid.

Because coal power stations are huge, when they drop out, they pose a significant threat to the entire grid – not just potentially leaving demand to outstrip supply, but the disruption of removing such a large amount of power suddenly and unexpectedly can shake the frequency and voltage of the system outside of safe operating bounds.

And they do regularly drop out, often when they are being particularly relied on – in hot weather and during periods of very high demand.

One way to see that is to look at a tally kept by the the Australian Energy Market Operator (Aemo) of what it describes as “non-credible contingency events” – that is, things it doesn’t specifically plan for.

Those mostly involve problems with transmission lines outside generators. Just looking at the list from 2017, there were seven localised events involving a range of generators – coal, wind, gas and hydro.

The two events that involve wind farms resulted in less than 30MW of supply being dropped out of the system.

When a gas plant tripped, 20 times more power was ripped out of the grid – a full 610MW. That event in South Australia nearly caused a repeat of the statewide blackout from earlier in the year. In fact, it created very similar conditions, but as a result of changes to settings on wind farms after the blackout, the system was able to ride through it without collapse.

But even that trip pales in comparison to two events on the list that involve coal, when more than a 1,000MW was dropped from the grid each time.

And that list doesn’t even include the more likely and common faults that happen inside power plants, rather than the transmission lines outside them…….

Coal power plants don’t generally provide capacity contracts
But here’s the real kicker: all currently available information suggests that the “reliability obligation” will all but explicitly rule out coal.

The Energy Security Board’s letter to the government says the reliability obligation will require retailers to buy a minimum amount of “flexible dispatchable capacity”. But most coal power plants are very inflexible – unable to turn on or off quickly…….

Of course, there has been virtually no detailed information about this obligation yet and so it’s not inconceivable that it could work differently, and find some way to incentivise coal generation. But it’s hard to see how that would lower energy prices, lower emissions or increase reliability of the grid. https://www.theguardian.com/australia-news/2017/oct/20/why-turnbulls-new-energy-plan-may-not-be-so-good-for-coal-explainer
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October 20, 2017 - Posted by | AUSTRALIA - NATIONAL, energy

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