Qld looks to voltage changes to encourage more rooftop solar | RenewEconomy

Qld looks to voltage changes to encourage more rooftop solar

Queensland says proposal to lower voltage standards will allow networks to more easily accommodate rooftop solar and other technologies.


The Queensland Labor government is looking to change the state’s statutory voltage limits – and bring them in line with the rest of the country – to help encourage more rooftop solar and other renewable energy.

Energy minister Mark Bailey announced the proposals at an energy storage conference in Brisbane on Wednesday, saying that the government was looking to align the state’s current requirement of 240 volts and changing this to 230 volts, as in the rest of the country.

Solar Panel and High Voltage Tower

“We are confident it will allow more efficient management of voltage issues caused by high penetration of solar PV, and support more renewable generation on Queensland’s electricity networks without adding to network costs,” he said.

The Queensland government is aiming for 50 per cent renewable energy by 2030, and solar is its main focus, seeking another 3GW by 2020 and more than 10GW by 2030.

Bailey says the government is also looking to streamline assessment processes for rooftop solar and battery storage.

This would include changes to requirements of rooftop arrays of up to 30kW, setting technical assessment thresholds by export limit rather than inverter capacity; moving from a zero export limit requirement to full, partial and minimal export limit requirements; and allowing reactive control and response mode inverters.

Bailey says the changes will provide greater flexibility for electricity distributors to operate the electricity network, increase embedded generation (solar and storage) hosting capacity and lower costs for grid upgrades.

The lower voltages is considered crucial also for new concepts such as peer-to-peer trading and blockchain technologies, and is part of a push for the whole of Australia to shift the settings on its low voltage network – which services 8 million customers – to around 220 volts, in line with new appliances and other technologies, and international practice.

Experts say that the ability to lower the normal operating voltage of those segments of the network with a high penetration of rooftop solar reduces the risk of exceeding maximum voltages when generation levels are high.

Until now, the distributors have needed to rely heavily on connection restrictions or expensive network augmentation in places where the appetite for customers to connect embedded generation is high.

Queensland and Western Australia are the only states that still require the supply of electricity at a nominal 240 volts per phase, with other states having adopted the 230 volt level prescribed by Australian Standard 60038 some years ago.

The significant adoption of embedded generation within the low voltage supply system has brought a new awareness of the design, operation and future of the thousands of kilometres of low voltage circuits that supply energy to the vast majority of electricity consumers.

Previously the ‘poor cousin’ of distribution networks, the LV is now demanding much more attention on voltage management, fault protection and connection contractual arrangements with customers.

Experts say that distributors traditionally operate the distribution system close to the very top of the permissible voltage range, as a protection against the risk of the voltage falling below statutory limits at times of high demand.

In recent times, however, the energy feed-in from a high penetration of embedded generation leads at times to voltage rise, challenging this operating paradigm, and leading to significant increases in customer complaints of appliance damage or inverter tripping due to high connection point voltages.

So much has changed in the voltage requirements of residential appliances. Switch mode power supplies, low voltage lighting and appliances built to international 220-240 volt standards have become commonplace in recent years.

The key is for distributors to be able to adopt lower operating voltages, permitting more voltage rise from embedded generation; whilst at the same time reducing the risk of any new problems stemming from voltages falling close to 200 volts in homes at times of high demand and no generation.

Demand management, replacing old appliances and clever transformer tap controls all form part of this new balancing act.

As one source said: “The proposed change in Queensland is to adopt the wider voltage range, setting the stage for new thinking in the operation of low voltage supply networks by all distributors to, deliver a platform for local energy trading, greater penetration of embedded generation and more efficient appliance operation.”

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  1. Chris Fraser 4 years ago

    My poor cousins in Queensland will assume their kettle no longer works. Let’s try to ensure there are no unproductive rumours going about …

    • john 4 years ago

      Having very high voltage supply does damage equipment so this is a sensible move.
      However the old 1920’s tap transformers that are not dynamic do present problems at the street level.
      I note one mention of this ” clever transformer tap controls all form part of this new balancing act”, by clever i would expect that would be remote adjustable; and to replace the number of street level transformers would be a very large cost.

      • FeFiFoFum 4 years ago

        There is a product available to retro fit distribution transformers with an “on load” tap changer.
        Old world distribution transformers have “off load” tap changers as the network was never designed to have generation embedded at the customer end of the network (surprise surprise !)

        All problems solved once the LV distribution voltage is regulated to keep it withing a bandwidth to allow for solar generation to feed into the network and for the voltage to not go too high to blow up your domestic stuff 🙂

    • Rod 4 years ago

      I can’t imagine any residential customer even realising it has changed.
      Just don’t tell them.

  2. Ray Miller 4 years ago

    The Queensland objective to fall into line with AS60038 is laudable and may give an additional margin to more PV systems.

    While doing some work for a small research project at the domestic level in 5 states the common theme was high voltage (exceeding 250V) outside of solar generation time. While the sample size was small, what are the chances of having a similar regime outside of PV generation time in 5 states?

    Indications are that the management by the distribution companies of the customer interface has been completely neglected. It would seem that not only are the taps at the local transformer incorrectly set nor are the phases balanced. Most of the problems are historical with a range of reasons from the short arm syndrome by lines person in the aerial distribution, to high infill growth in some suburbs. The problems have commanded over time and since now we have these PV inverter with accurate monitoring and control systems reporting problems. What has tended to happen is the distribution companies blame the solar for the growing voltage problems but it would seem the blame is wrongly attributed, where the problem is management.

    • john 4 years ago

      Just rang a person to go check 249 Volts atm.
      Without up sized wiring the system would be failing due to over voltage automatic disconnection by the inverter.

  3. Jeff Wehl 4 years ago

    This is sorely needed. The voltage ramping happening on PV systems since the latest standards change is just absurd.

  4. Phil 4 years ago

    I used to lose an appliance a year in Brisbane due the mains voltage regularly hitting 253 volts

    It was worst on partly cloudy days with the solar panels of neighbours contributing to the grid voltage variation as the sun appeared or went behind clouds.

  5. Kevin Brown 4 years ago

    The “Smart State” Queensland yet again takes a trophy for being last to adopt a policy the rest of Australia has implemented! Here was I thinking that Queensland was starting to catch up with the rest of Australia by recently making fraught changes to supermarket opening hours so I can now shop in my local Coles and Woolworths from 7.00 am to 9.00pm.

    Jeez, sometimes/most-times it is tough being a “Queenslander!!!!!”

    • FeFiFoFum 4 years ago

      Tougher being in WA !!
      We used to run 254V and have reduced to 240V with no changes in sight to further reduce below 240V.
      I reckon we get the wooden spoon here ??

      And we still haven’t got 07:00 opening hours for much of anything …

    • Alan 4 years ago

      WA is in last place. Practically the only inverter we can install now is Fronius as it ramps down the output rather than disconnecting under high voltage conditions like just about every other inverter including SMA!

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