Rooftop solar continues to take a big bite out of the business and operating model of Australia’s main grid, hitting new output records on Sunday and sending minimum demand records tumbling across the country.

According to data provider GPE NEMLog, rooftop solar PV hit a new peak of 48.6 per cent of total generation at 1.50pm (AEST) on Sunday, breaking the previous record of 48.4 per cent it had set at the start of the month.

But more importantly for the grid operators and competing technologies, it helped push operating demand across the National Electricity Market down to a new low of 11,009 MW, down around 215 MW from its previously low, also set on October 1.

Record shares of rooftop solar and operational demand were also set in Victoria, where rooftop PV hit a new peak of 60.1per cent of generation and sent operational demand down below 2GW for the first time to a new minimum of 1915 MW.

Rooftop solar also hit a new record share in NSW – the country’s biggest state grid – with 50.4 per cent, the first time it has contributed more than half of generation, and also set a new low for operational demand in NSW of 3664 MW, down 200 MW from the previous low. NSW still has more than 8GW of coal generation.

Tumbling operational demand levels usually means bad news for coal generators, which often get squeezed out of the market and have to bid down towards the market floor (minus $1,000/MWh) to keep running. They reckon it is cheaper to pay someone else to take the output than to switch off.

In South Australia, however, there are no coal generators left in the system – the last one closed in 2016 – and so the biggest victim of high rooftop solar PV outputs is usually utility scale solar.

On Sunday, the output from utility scale solar fell to less than one megawatt in the middle of the day as more than 455 MW of utility scale (a new record) was curtailed.

Unlike coal fired power stations, solar projects reckon its cheaper to switch off than to pay someone else to take the output. And some are obliged to do so anyway under the terms of their contracts.

There has been a slew of renewable energy share records in the grid across the last few months – spring is often the “record season” because of the good conditions for wind and solar farms and relatively mild weather. And each year the numbers are boosted by new additions to the grid.

Earlier last week, the share of renewables across the NEM hit a new instantaneous record of 72.5 per cent, and wind and solar alone hit a new peak of 70.8 per cent.

The level of “potential” renewables also hit a new peak – potential means actual output plus curtailed capacity – and reached more than 101 per cent of demand in one five minute period, and 98.5 per cent in one half hour period.

In South Australia, the records have been even more dramatic, with rooftop solar alone providing more than 100 per cent of demand, operational demand hitting a new low of 21 MW (over 30 minute period and negative over a 5 minute period), and “potential” renewables (just wind and solar) hitting a new peak of 264 per cent of demand.

In response, more batteries are being built, other longer duration storage technologies such as solar thermal are being considered, and the South Australia is also betting big on green hydrogen, where the use of electrolysers and hydrogen-powered generators can help lift minimum demand, and respond to peak demand issues.

  • abhibeckert@beehaw.org
    link
    fedilink
    arrow-up
    15
    ·
    edit-2
    10 months ago

    At this point I think you’re crazy if you don’t have solar on the roof. Why buy electricity when you can get it almost for free?

    Even rentals - landlords are allowed to raise the rent by more than the cost of installing the panels, and tenants will save thousands of dollars on their electricity bill, meaning they stand to gain just as much financially as the landlord even after paying extra rent.

      • abhibeckert@beehaw.org
        link
        fedilink
        arrow-up
        4
        ·
        edit-2
        10 months ago

        My roof is over 30 years old and has shade, installing solar was cheap (they took 4 hours) and despite the shade generates more power than I can use.

    • wscholermann@aussie.zone
      link
      fedilink
      arrow-up
      3
      ·
      10 months ago

      Apartment buildings unfortunately add a layer of complication. It’s not always insurmountable depending on the building type but even so not as straightforward as throwing a few solar panels on the roof.

      • abhibeckert@beehaw.org
        link
        fedilink
        arrow-up
        1
        ·
        10 months ago

        Not sure about other states, but in QLD you are required to “request consent” from the body corporate but it is illegal for them to say no. The only option the body corp has is to instruct you where to put the panels and even then, they have to be reasonable - for example if there’s no space on the roof above your apartment, maybe because it’s full of panels already, they have to allow you to put panels somewhere else such as on common property.

        • wscholermann@aussie.zone
          link
          fedilink
          arrow-up
          4
          ·
          10 months ago

          That becomes difficult in multistory buildings, where the roof could not accommodate all solar energy panels dedicated to specific lots, and if you are on the ground floor it gets difficult. Many buildings really don’t have anywhere else to put them.

          Then it becomes a case of solar panels as “common property” and that’s when things get really messy.

          • abhibeckert@beehaw.org
            link
            fedilink
            arrow-up
            1
            ·
            edit-2
            10 months ago

            If there is an “exterior surface” that doesn’t currently have a solar panel on it, then any apartment owner is allowed to install a panels on it.

            Body corporate can instruct the tenant to install the panels somewhere else instead, and they can block a single apartment from covering the entire complex in panels but they cannot refuse a reasonable request which includes installing panels on a section of roof above someone else’s apartment or on a car park roof. Pretty sure you can even install panels on the walls, though it wouldn’t get much sun unless it’s a sky scraper.

            You can’t block them and it’s not difficult - you just ask an electrician to draw up an installation plan, which is usually free, then email that plan to the body corporate. If the body corporate refuses, then you can report them to the council and the council will give them a legally binding order to approve the plan - unless the proposal is totally unreasonable. There’s basically no work at all for the owner of the apartment.

            Also - you’re massively overestimating how many panels are needed. For most of the day our house draws 300 watts. A single solar panel produces more than that. You can probably fit enough panels hundreds or even thousands of apartments on the roof of a large apartment building.

            Yes - sometimes we draw 2000 watts, but only briefly - the entire building is never going to draw that much power from every apartment at the same time. Even if they do, so what. It’s still significantly reducing the amount of power drawn from the grid… and during the day these days about half the grid power is from solar (with more being installed every day).