New standard could restrict and add costs to extra solar and battery storage | RenewEconomy

New standard could restrict and add costs to extra solar and battery storage

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New Australia-wide standard gives networks power to limit size of household solar systems – and could push up prices for AC-coupled battery storage products from Tesla, Enphase, Selectronic and others.

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One Step Off The Grid

A new, Australia-wide electricity standard has been introduced that gives networks the power to limit the size of household solar systems – including some solar plus storage configurations – and which could add significant costs to households looking to add more solar or install some battery storage systems.

The new standard, known as 4777.1, which has just come into effect, defines the maximum capacity for inverters at a single phase domestic site to be 5kW, unless otherwise allowed by the local network.

It means that households wishing to install a system larger than 5kW – or to add more capacity to their existing system, be it through more panels or an AC-coupled battery – risk either being refused the request, or having to pay thousands more for an upgrades to three-phase power.

The move appears to be aimed at giving networks some control over the amount of domestic solar that is coming onto the system – particularly, from those households looking to increase the size of their PV systems after the closure of premium feed-in tariffs.

But a number of industry insiders told One Step Off The Grid on Wednesday that it would also have the unintended effect of limiting battery storage uptake – something networks should be encouraging, as a potentially valuable asset, as more and more distributed solar comes on-line.

More specifically, the complexities of the new rule threaten to be a major thorn in the side of a number of key AC battery makers and installers – including Tesla, Enphase and Selectronic – placing unnecessary restrictions on the uptake of their AC-coupled products.

“Let’s say you have an existing 5kW solar system, and you want to add 4kW of Enphase of AC batteries,” one industry source explained; “the new standard defines that new system size is 9kW, and therefore open to the network to reject.

“If I was Tesla, I would be going round the twist!” said the source.

According to Geoff Bragg, from NSW-based company New England Solar Power and the head of the Solar Energy Industries Association, the new rule creates a “pain in the neck” for battery storage installation.

And it comes, ironically, at a time when battery storage uptake should be being encouraged by networks, for its role in soaking up excess solar generation and in shaving peak power demand – not to mention the “virtual power plant” benefits promised to networks through the addition of smart software and energy management, such as is being tested by AGL and other utilities.

“We would hope that networks will see sense and allow AC coupling, where it can be demonstrated that it is not going to cause voltage rise issues,” Bragg told One Step. But he said on one recent installation, it had taken four applications before the local network owner, Essential Energy, agreed to the upgrade.

It is affecting those that want to simply upgrade their solar systems, including RenewEconomy contributor and ITK analyst David Leitch, who was told he would have to upgrade to 3-phase, at a cost of several thousand dollars, because he wanted to lift his solar system from 4kW to 6kW.

As Leitch has noted in this analysis, for those high energy consumption households who want a PV system big enough to charge a battery, and perhaps help power a pool pump and air-conditioning, it takes what would have been an economically sound decision back into the realm of ideology.

“It’s just yet another thing that will piss people off. Maybe push people off grid,” said another source.

This article was originally published on RenewEconomy’s sister site, One Step Off The Grid, which focuses on customer experience and ambitions with distributed generation. To sign up to One Step’s free weekly newsletter, please click here.

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18 Comments
  1. Darren 3 years ago

    Regulate all the things.

    • Jo 3 years ago

      What reason for this restriction is offered?
      I could understand a limitation of 5kW for export on a single phase from each household. But restricting solar capacity that will never be fed into the grid is just pain ‘throwing spanner in the works’. If the potential overload of the grid is indeed an issue, let’s just have an export restriction to 5kW, but no restriction of the solar capacity. This can be done by an extra ‘export limiting box’ but I guess that this can be easily implemented in an inverter if necessary.

      By the way, Ausgrid has already an inverter limitation to 5kW per phase for domestic applications.

      • Darren 3 years ago

        to me, as someone who would like to get battery storage as soon as its $$$ possible this just stinks of delay tactics. An artificial way to stop the death spiral.

        Also seems to be knife to Virtual Power Plant and Things like Greensync’s deX.

        Ergon already has limitations in QLD (unless since changed) but you cant at last look get more than 5KW.

        • solarguy 3 years ago

          Darren, don’t be to worried about it, there ways around it on a single phase connection. And storage is only limited to how big your loads are. Oversizing PV is one of the answers.

          • Gavin Spring 3 years ago

            Hi I was wondering if there were any options for my situation? I have a 2kw existing Aurora inverter about 7 years old. Last week I had a 5kw SMA inverter installed along with 22 x 290 panels. Essential Energy approved the system to be coupled and connected to the grid. However it turns out that my original approval was for a SolaEdge (SE) inverter not an SMA. So Essential Energy are now requesting an export limiter, which I do not want.

            The two systems are up and running via a smart net meter.

            The previously approved SE 5kw inverter has an output of 23 amps AC. Where as the SMA has 22 amps AC.

            I’m confused why the higher output system was approved but now the lower is not and a limiter required.

            I went ahead with the installation based on the original approval to connect, not realising that a change of inverter would create such a hassle.

            Any suggestions.

            Cheers

            Gavin

          • solarguy 3 years ago

            Ask Essential and your installer as to why.

        • humanitarian solar 3 years ago

          It’s not going to stop load defection because installers will just configure new systems to feed PV into batteries, especially PV above 5kW. The rule may increase risk of a death spiral, as it will focus installers even more towards batteries and discourage grid interaction by limiting exports to 5kW. Because exports are limited, once the battery is full and household loads are taken care of (family not home) the solar system will attempt to export everything though once the 5kW limit is reached, the system will have to throttle back on solar harvest to prevent overcharging the battery.

      • solarguy 3 years ago

        Jo, there is no restriction on the PV, just the inverter is limited to 5kwp output, so PV can be oversized!

      • solarguy 3 years ago

        Oh, forgot to say the reason for throttling inverter output on a single phase is because our grid wasn’t designed for two way traffic. It was an engineering decision.

  2. trackdaze 3 years ago

    Sounds to me like we are contriving regulations to protect generators?

  3. nakedChimp 3 years ago

    What’s the problem?
    You put solar on your roof to feed it into the grid or to use it yourself?
    If the latter – good for you.
    Request a hybrid inverter system from your solar installer that can be set to export nothing or max of 5kW and is able to deliver 15kW peak and 5kW continuous (hint, not available yet).
    Install a battery (5-10kWh) and use the remainder of the solar yourself.
    Change your house power installation to be able to go into island mode without the grid.
    Once the grid becomes too expensive – more than your own local behind the meter backup (I guess 30-50kWh battery, standard in 10-15 years) – cut the cord.

  4. aussiearnie 3 years ago

    There appears to (again) be confusion between kW and kWh… “you have an existing 5kW solar system, and you want to add 4kW of Enphase of AC batteries”. Nope, the batteries will be kWh, not kW. And adding those two numbers is just dumb. Who will be dumping the power from the solar panels and the battery into the grid at the same time??

    • Andrew Woodroffe 3 years ago

      Indeed. The individual involved sounds like he should not be . . . involved. It is like confusing the horsepower of a car engine with the litres of fuel that can fit in the petrol tank.

  5. Greg Hudson 3 years ago

    Who was it exactly that decided this new standard 4777.1 ? What org could possibly cover all of Australia? A Federal dept ? If so, sounds like links to the FF industry (again)…

  6. humanitarian solar 3 years ago

    I’m not sure of this article is a completely accurate interpretation of the rules. Here’s my go at it:

    “It means that households wishing to install a system larger than 5kW – or to add more capacity to their existing system, be it through more panels or an AC-coupled battery – risk either being refused the request”

    IMHO this statement could surely only apply to PV connected to grid-tie inverters and PV AC coupled onto the AC output of hybrid inverters, because at various times, this PV will inevitably be exported at it’s maximum power rating into the grid. So that’s why no more than 5kW of PV could be connected in this configuration, because allot of it is going into the grid. This is not so for DC coupled PV which is on the DC (not the AC) side of the inverter, because this PV is going into a battery. So this DC coupled PV is behind the inverter and even if it were 500kW of PV there’s no chance it will be exported because the new rules cap the inverter at 5kW. This is what I believe needs to be designed into the solar system configuration (by the installer), that there is no PV installed that’s not on a 5kW “leash”.

    “But a number of industry insiders told One Step Off The Grid on Wednesday that it would also have the unintended effect of limiting battery storage uptake”

    How could this statement be so? We could have the same amount of PV and storage as South Australia and as long as it sits behind a 5kW inverter making sure no more than 5kW is ever exported, there’s no problem. We will likely need a huge amount of PV and storage to charge an EV and no problem for our 5kW hybrid inverter because 5kW x 10 hours of inverting = 50kWhrs into the EV. So there’s still lots of PV and storage needed!

    “More specifically, the complexities of the new rule threaten to be a major thorn in the side of a number of key AC battery makers and installers – including Tesla, Enphase and Selectronic – placing unnecessary restrictions on the uptake of their AC-coupled products.”

    It’s only the products which are exclusively AC coupled which are effected. For example, Selectronic hybrid inverters can be AC or DC coupled, so installers can just keep all the PV strings on the DC side of the inverter. So we could have a million PV strings and a million Solar Regulators feeding them into a battery if our battery is big enough. My understanding is the only reason installers “AC couple” PV onto the output of hybrid inverters (meaning it’s run through a dedicated PV inverter first), is when the PV has a large distance to travel from another building. If that still needs to happen, there’s other options for getting it there without breaking the rules, like using a hybrid inverter that can manage 2x external AC inputs.

    “If I was Tesla, I would be going round the twist!”

    I suggested to neroden it might be good to have the Powerwall redesigned, so it can have the PV strings DC coupled directly into the battery.

    “not to mention the virtual power plant benefits”

    Screw the “virtual power plants” because it’s cheaper for them to buy their own batteries and they should, rather than using ours.

    “As Leitch has noted in this analysis, for those high energy consumption households who want a PV system big enough to charge a battery, and perhaps help power a pool pump and air-conditioning”

    For this it would help to buy a quality hybrid inverter with load management, that can have loads staggered throughout the solar day.

    This picture shows the problem with how the Powerwall 2 is AC coupled, typically having a PV inverter on its output, “unleashed” and pointing straight down the grid (if by chance it isn’t first soaked up by a hungry battery). So to me, the PV is a potentially uncontrolled problem for the grid).

    https://uploads.disquscdn.com/images/6c1d40a12f79a3f16c4c0505603fae00f857bfcb1b9bbc5092212ed53bbe9416.jpg

  7. Ray Miller 3 years ago

    While limiting the maximum export to 5 kW VA (true power in some inverters is limited to 4.5kW) for the single phase grid connection but the same connection does not limit the draw from the grid. That would mean that if you had a limited 5kW PV inverter and an air conditioning maximum load of 6kW plus any other loads you would not be an exporter under extremes of temperature only because of distributor rules? This situation is no where near acceptable and I would have no problems telling the distributor where to go and what are they going to do about it?

    We have also other ways of getting around the situation where it would benefit all concerned, break the systems into two arrays and have a western facing and north facing array. Essentially having an east-west tracking using fixed panels, adding a small amount of battery storage would also be helpful with a larger inverter limited to the maximum grid export but allowing for greater self consumption.

    • humanitarian solar 3 years ago

      The rules appear designed to limit exports to 5kW at any time, so loads which are all discretionary, are not taken into account. There’s no limit to the PV we can have it just has to be controlled by feeding it directly into a battery rather than the grid. After the battery is full, up to 5kW can still be exported. So new installs will be more limiteconfigurations and it will mean some old systems need to be reconfigured before adding additional PV.

  8. humanitarian solar 3 years ago

    With Giles enphase system, maybe an option is move all the panels to one roof, so all the gear is retained and the panels look consistent, then when it’s time for the EV get a second off grid solar system. It could use a hybrid inverter with “charger only function”, so it never exports. When claiming the STC’s it’s ticking the box that says off grid for registering the system. Then it would be shifting the most important circuit breakers to that system, because it will have plenty of power in outages. The enphase could still function uninterrupted for it’s fine performance as a grid interactive system.

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