rss
14

Qld turns to jet-fuel and imports as coal plants wilt in face of record demand

Print Friendly, PDF & Email

The pro-coal and anti-renewable brigade have been quick to pin the blame on renewables for any price spike or supply squeeze on Australia’s National Electricity market over summer.

How frustrating it must be for them that there has not been a major blackout – apart from outages caused by storms in Queensland and local network failures in Victoria. They really, really wanted one to happen.

So it will be interesting to see what they make of events in Queensland this week – the state with the biggest coal fleet that was forced to turn to plants powered by jet fuel, and imports from NSW to ensure the lights stayed on in the middle of their heatwave.

Queensland on Wednesday afternoon hit a record peak grid demand of just short of 10,000MW – and it might have been over 10,000MW were it not for the 370MW of rooftop solar satisfying some household and business demand.

It was the third consecutive day of record demand in Queensland – and extraordinarily the last peak on Wednesday was more than 500MW higher than the previous peak (January, 2017) before this current heatwave.

As this graph above shows, the peak would have been even higher without solar, which not only clipped the peak by a considerable margin, but also pushed it later in the day. (Sorry, can’t explain difference between this graph’s estimate of peak demand, and AEMO’s).

Just as well rooftop solar was there, because it appears that at the peak some of the state’s biggest coal generators wound down their output, likely because of heat issues that were putting stress on plant and equipment (as intense heat often does).

Milmerran was operating at just 70 per cent capacity, and there were unexpected outages at Gladstone (the biggest coal plant), and at Braemar (gas), according to the Australia Institute’s Gas and Coal Watch.

All told, analysts estimate the state’s coal fleet was delivering around 1,000MW less than its capacity at the time of peak demand.

 

This meant that the grid operator had to turn to the state’s considerable combined cycle gas plants and its peaking gas plants, and – as it does on rare occasions -it also called on the Mt Stuart peaking plant that burns kerosene, or jet-fuel.

(See our graph above taken from our excellent new wider, OpenNEM).

Ironically, Queensland also turned to imports to fill the gap between supply and demand, importing 177MW, or nearly two per cent of its needs, from NSW at the time of its peak.

And where might those imports have come from? Most likely from the power generator closest to the border (that’s the way electrons flow), so it would have been the 175MW White Rock wind farm near Glen Innes, in the heart of Barnaby Joyce’s electorate, that was putting out around 140-150MW at the time.

This is not to suggest that the Queensland grid failed in some way. It is to point out that all grids – coal or renewable – struggle to meet such peaks in demand.

And all grids – coal-based or renewable – need back-up capacity to meet those peaks. And all grid, coal-based or renewable – like to export and import to and from neighbouring grids. It’s the way the market is supposed to work.

Mt Stuart, in north Queensland, is one of dozens of such generators that are switched on for just a few hours of the year. It burns kerosene, or jet-fuel in its three turbines, and in the six months to December produced just 3,000MWh of electricity, or about seven hours of production at capacity.

These and other turbines were installed decades ago (Mt Stuart in 1999), long before renewables became a thing. So to suggest that their use in renewables-based grid is somehow a sign of the fallibility of renewables is patently absurd.

It was also interesting to note that during this heat wave, prices in Queensland spiked to more than $350/MWh, while prices in South Australia and Victoria both dipped into negative territory.

The Queensland prices might have spiked more, as they did in last year’s heatwave in January and February, when they regularly hit the market peak of $14,200/MWh, but the state-owned generators are now under strict instructions from the government not to use their market power in such a way.

I guess it’s one of the advantages of state-owned assets. South Australia must be envious.

It will be interesting to see what happens when the current 3GW of large solar and wind capacity, along with some battery and pumped hydro storage, is added to the newly 2GW of rooftop solar in coming summers.

   

Pocket
  • Ray Miller

    My home at the southern end of the Gold Coast yesterday was off the grid from 6am-6pm running on my backup 300Wpvpeak tracking and battery system. Two people working from home, running laptops etc. Then when on the grid with <200watts.
    My high star rating home was cooler inside all day up until 6pm, peaking at 28.5C at 5pm, outside peaked at 33C at 1:45pm, only needed the fans a little.
    So my question is why the peak electricity demand on a hot day is so large if our buildings are fit for purpose?
    Why is the National Construction Code delivering buildings not fit for purpose and refuse to do anything about it when the net benefit is an overall saving of billions of dollars?
    http://www.asbec.asn.au/research-items/bottom-line-household-impacts-building-code/
    Heat is a thermodynamic physics problem, all our machines will not and cannot work to their full capacity under high ambient temperatures. Our machines pumping heat suffer the same problem, on a hot day their efficiency drops of a cliff, notably the same time our energy system is wound back and prices skyrocket. Can anyone see the problem?

    Just maybe doing something about the heat entering our buildings maybe a solution worth following up on?

    • Shaun

      Absolutely agree. Building efficiency has to improve or otherwise all we will be doing is using solar electrons to create an even worse heat island effect outside our homes.
      Tree cover, external shading, insulation. Problem is in part the fact that buy to let ownership is so high with many landlords not interested in efficiency or comfort.
      Must be some way of capturing the waste heat from AC and using it for useful work,

      • James Hansen

        I agree with the comments above.
        Two points come to mind.
        1. We need to look at establishing an offshore wind farm (say) in shallow water north and east of Moreton Island as an insurance against transmission failure on a major line from Gladstone, Tarong or Millmerran for example. 12 of the most modern and efficient wind turbines arguably could generate 300MW in a reliable wind area without being a hazard to aviation operations at Brisbane or Maroochydore. A short distance to consumption area with battery backup may cost as little as about 4c/kWh. A skilled and reliable workforce could always be available nearby.
        2. We must encourage and assist landlords to install solar panels on rental properties without financial detriment to their tenants.

        • George Marsh

          Interesting example of what is being done elsewhere – which will result in lots of Jobs and Growth – and we have the shallow waters of Moreton Bay somewhat similar to the Burbo Bank off Liverpool UK.
          http://www.bbc.com/news/uk-england-merseyside-11753773

      • Pixilico

        Indeed, there are ways of capturing it and the whole thing doesn’t seem to be overly complicated, either: https://www.achrnews.com/articles/125740-doucette-industries-inc-refrigeration-ac-desuperheaters

    • nakedChimp

      You just have to look what they still build up here in Cairns and surroundings.. hacked up roofs (following the ridiculous outline of the rooms below), thermal mass (if any) right on the outside (concrete, brick veneer) and then some insulation mats to the inside where you then have gyprock.
      Roof spaces separated from your living area by gyprock and some mineral wool or other fluff.
      Windows are naturally single pane and gappy.

    • Joe

      No need to worry about building energy efficient homes here in Australia. The punters just need to …acclimatise themselves.

    • Roger Franklin

      Ray – my home in Brisbane has been off the grid for 18 months – run Air Con on hot days and just about every other electrical appliance you can have in your home – with zero problems. Home design and in particular insulation and shading all helps, but so does sensible use of energy. We have been conditioned to have this endless supply of energy – but comes at a cost.

      One fool by themselves is not a problem but two or more fools together can be a disaster. In this case we have energy consumers expecting and endless supply of power and energy generators prepared to supply it – but at a cost! Like speeding fines, the best way to avoid them is to slow down. In the world of power – use less and or generate more yourself and use it first before using the grid power.

    • Ken Dyer

      With present planning and development regimes, developers tend to plonk green space where-ever they can. If they did not have to, then suburbs would be wall to wall housing tenements.

      As it is housing developments put houses on blocks of land with no thought of orientation to take advantage of climate or access. Development design is merely to make as much money as possible and the poor new homeowner must then put up with a house that is poorly orientated for the prevailing climate, on small blocks too close to neighbours so you cannot plant for shade, and inadequately serviced and constructed from materials unsuitable for climate.

      We have been brainwashed in Australia that everybody should have their own freestanding, 3 to 4 bedroom, 2 bathroom bungalow with double garage to store stuff and a short drive where cars can be parked. Urban sprawl is the default housing in Australia, and until local governments (in Queensland at least) are brought to heel insofar that developer donations are banned, this default position will continue as long as a buck is to be made.

    • MaxG

      The building code is basically written by the industry, with the aim to bang the box together as efficiently as possible. More energy efficient houses are more expensive to build. Neither builder nor customer have an interest in higher costs, and out of the window goes energy efficiency.
      I have established a net zero property (not only house, but the lot)… and am currently owner-building a passive house. I will neither need heating nor cooling. However, trying to build to the passive house standard has significant challenges, given how Aussie code demands them to be built. One is the roof being ‘loose’ above the walls. Trying to air-tight the ceiling becomes a nightmare. (And I haven’t even mentioned electrical and plumbing.) The low roof angles make it very difficult to insulate the over the top plates of the walls (allowing only for R2 or 100mm of insulation to go into the gap, without hitting the reflective foil under the battens. And I could provide numerous obstacles, which is due to the ‘sh!tty’ code.
      Try to put a 180mm German double-glazed door frame into a standard wall! :)) I basically put a double frame up. yadda yadda…

  • Jon

    Was the pumped hydro being used at the time?

    • Jonathan Prendergast

      Yes it was. 150MW during the high price period. 300MW just after.

      • Mike Westerman

        150MW out of 500MW – pathetic. No doubt actually being used as spinning reserve to guarantee its owner’s black coal, rather than to load shift. We need another few GW asap to support the new solar and wind.