Rooftop solar provides 48% of South Australia power, pushing grid demand to record low

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South Australia’s level of minimum demand hit a new record low this weekend – barely a week after the previous benchmark was set – with a fall to just 587MW on Sunday afternoon.

The record eclipsed the previous mark by nearly 200MW – with AEMO data showing minimum demand at 1.30pm of exactly 587.8MW, compared with the previous low mark of 786.42MW posted last Sunday. (See graph above courtesy of Melbourne’s Climate and Energy College).

The key here appears to be the moderate temperatures of early spring, which meant few air conditioners switched on, combined with excellent solar output, with the state’s more than 700MW of rooftop solar producing 538.54MW at the time of minimum demand.

That is a phenomenal share of 47.8 per cent of the state’s electricity demand being met by rooftop solar (compares with 36 per cent in the previous record last week) and is clearly a record for South Australia, and for that matter in any large grid anywhere in the world.

As we reported last week, the tumbling records confirm that the times of record low demand have shifted from the night to the middle of the day.

The Australian Energy Market Operator has predicted that by 2019, record low demand may fall to just 354MW, and within 10 years the grid demand may fall to zero because of the increasing amount of rooftop solar. This is also likely to occur in Western Australia around the same time.

South Australia is the first region where rooftop solar PV has caused a shift in minimum demand from night time to the middle of the day (most states still have electric hot water being switched on at night, when it would make sense to use the “solar sponge” as Queensland has suggested).

The impact of rooftop solar is being felt in prices – look at the black line that shows prices fall as rooftop solar accounts for a sizeable share of demand during the day.

Note, also, the negative price of minus $44/MWh at 6am when there was abundant wind and a constraint on the connector with Victoria.

South Australia is the first region where rooftop solar PV has caused a shift in minimum demand from night time to the middle of the day (most states still have electric hot water being switched on at night, when it would make sense to use the “solar sponge” as Queensland has suggested).

“It’s absurd to continue having hot water heating at this hour,” says Dylan McConnell, from Melbourne’s Climate and Energy College.
“It’s completely contradictory to the original intention of having water heating at this hour : to use ‘off-peak’  electricity. In many cases, this is actually the peak – and off-peak has shifted to the middle of the day.”

AEMO chief Audrey Zibelman has welcomed this change in technologies and load curves as “not a bad thing”, but they do have to be managed differently.

It also questions the need for old fashioned concepts such as “baseload”, which would struggle to find a niche in a market dominated by wind and solar, where mostly “dispatchable” and flexible generation is needed to fill in the gaps. Wind energy is already producing more than 100 per cent of local demand at certain times.

As we note in our updated story about prime minister Malcolm Turnbull’s rooftop solar and battery storage system in his Point Piper mansion, AEMO predicts that around 40 per cent of Australia’s supply could come from “distributed generation”, which effectively means rooftop solar and storage.

That sort of solar and storage is likely to be more useful to the grid operator than old coal fired power stations.

And new analysis from Bruce Mountain at Carbon and Energy Markets suggests exactly that: rooftop solar and battery storage systems would be better suited for AEMO to manage the changing grid than spending vast amounts of money in extending the life of ageing, unreliable and increasingly expensive coal generators such as Liddell.

Meanwhile, and despite starring on a state level, South Australia remains absent in the latest ranking of Australia’s top 10 solar postcodes, which you can read about on One Step Off The Grid, here.


16 responses to “Rooftop solar provides 48% of South Australia power, pushing grid demand to record low”

  1. Chris Drongers Avatar
    Chris Drongers

    Great! I thought the the 48% PV shown on the APVI chart must have been wrong, not so.
    When our parliament (no longer in the business of ‘governing’ in the traditional sense) establish sensible rules for dispatchability and FCAS we will be able to consign worries about electricity supply to their proper place – not a concern at all.

    1. MrMauricio Avatar

      yep!!Consign them to the rubbish bin of history-and move toward Solartopia (read the book!!!)

  2. BushAxe Avatar

    I reckon it’ll go lower than that in the next couple of months as we climb towards peak irradiation.

  3. juxx0r Avatar

    C’mon SA, pull your finger out and double your solar.

    1. Ren Stimpy Avatar
      Ren Stimpy

      NSW is the state with the biggest finger in the wrong place.

      1. juxx0r Avatar

        I’ll pay that.

  4. Tom Avatar

    Coal-fired power stations are really going to have to learn how to turn themselves on and off if they want to remain relevant, regardless of what other grid-scale generators are around. It doesn’t matter if it’s wind, gas, or hydro supporting coal if there’s no demand because everyone’s generating from PV behind the meter.

    Maybe each coal-fired power station could install a battery with power equal to their output and energy equal to 2 hours of power (eg, Liddell 1680MW, 3360MWh), so that the battery can provide instant power as the coal generator starts up until the power station is at peak output 2 hours later and can take over, and so that the coal generator can “turn off” instantly from the grid but recharge the battery over the 2 hours it takes them to wind down.

    1. Mike Shackleton Avatar
      Mike Shackleton

      I thought it took days to fire up and down a coal fired power station. For your 2 hour concept, it would mean the boilers would always be preheated and ready to go. That’s as wasteful as leaving your car idling in the garage all day in case you need to pop down to the shops.

      1. Ronald Brakels Avatar
        Ronald Brakels

        Coal power stations could use electrical resistance heating powered by renewable energy to maintain temperature and pressure during periods of high renewable output and low demand, but it would probably be easier to just shut them down for good.

        1. Mike Shackleton Avatar
          Mike Shackleton

          Electrical resistance heating – seems pretty archaic! Why not just get homes to turn on their hot water heaters instead of switching on at 1 am?

          1. Ronald Brakels Avatar
            Ronald Brakels

            Are you making fun of South Australia’s idiot spike? I’ll have you know that the spike in electricity demand that occurs when all the state’s off-peak hot water systems turn on within about 15 minutes of each other often isn’t the peak demand for the day. Of course, a fair amount of the time it is, and that is a little embarrassing…

      2. Tom Avatar

        To tell the truth I don’t really know how long it takes.

        I think it takes SA’s old gas-fired boiler about 4 hours, so I was assuming it would be something similar (which means you’d need 2 hours of full-power as battery storage if power came on in a straight line), but I really don’t know.

  5. BarleySinger Avatar

    The Power producers and the grid companies are fighting back against solar.

    South Australia has outlawed all new ‘small generator’ installs over 5KW (unless you have three-phase on your home).

    You used to be able to have an oversized 10KW system on single-phase. You used to be able to put 10Kw on a SWER if you used “export limiting” to keep your power out of the grid.

    Not any more. Now the cast majority of people would have to off entirely off-grid to have more than 5Kw of PV on the house. Battery tech just isn’t cost effective enough yet for ‘mass gird defections’ and they know it.

    The nations grid providers (like SA Power Networks) are helping the large providers to try & take back control of the solar power market, by building huge commercial solar projects. Big solar projects on the gird are good – except – at the same time they are changing the rules of the grid to increase their own profits (and that of the big generators – who DISLIKE the amount of roof-top solar we have put on our homes).

    These changes make it impossible for home owners to afford electricity, and impossible to offset it with enough solar. The new generation will not come on-line for years.

    The installers and the people MUST go to Weatherhill and get an ICAC going against the people who made those rules. What SA Power Networks is involved in is price fixing, collusion & the use of their regulatory powers to create a predatory electricity market.

    1. neroden Avatar

      Weatherhill needs to be directly contacted about this ban, which is both illegal and unimplementable.

      If you put extra solar on your house and don’t export it to the grid… well, it’s none of the grid’s business is it?

      Full defection is already going to happen among the wealthiest. Battery prices will come down and cause full defection among the middle class. If Weatherhill wants to avoid that, he needs to restore sane interconnect rules — allow anyone to put as much solar as they like on their house if they throttle the grid connection.

  6. Shagrath Avatar

    Hopefully we work out how to keep the sun up in the sky after dark, then we can rely on the panels to keep producing overnight! Imagine that!

  7. Drake Anderson Avatar
    Drake Anderson

    So how much has been spent on Solar?
    Will you every make this money back?
    South Australia(cents) per kwh 47.13
    USA (cents) per kwh 15.75

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