New rooftop solar, battery connection standards: What do they mean? Who needs to know?


Standardised guidelines to govern the “safe, consistent and efficient” installation of rooftop solar and storage across Australia’s National Electricity Market were released late last week by Energy Networks Australia.
As we reported here on RenewEconomy last week, the National Connection Guidelines mark the first nationally consistent approach for the installation of distributed energy resources, and – in this instance – address low voltage connections for household, commercial and industrial applications.
The key recommendation the guildelines are making to Distribution Network Service Providers across the NEM is that rooftop solar energy exports to the grid should be limited to 5kW across the board, while the networks try to get up to speed with managing what is a booming home solar market. No limitation is proposed to what can be installed behind the meter.
In comments on Thursday, ENA CEO Andrew Dillon said Thursday’s guidelines were about safe, consistent and efficient grid connections to help reduce costs for networks and customers.
“With so many households embracing solar and new personalised energy sources, these guidelines will ensure connection processes are streamlined and consistently applied across all jurisdictions,” he said.
And with the latest raft of state rooftop solar policy incentives driving distributed PV uptake more than ever, and a home battery market set to boom, the guidelines have certainly come at an important time.
But are the new guidelines a good, bad or indifferent outcome for consumers? Who do they affect? And what will they actually do?
We asked the ENA, and then the Clean Energy Council, to please explain…
Stuart Johnston, principal, Future Networks, ENA
RE: What changes with these guidelines?
SJ: The proposed standards should make things a lot clearer, in terms of what people can actually install behind the meter. Basically, people can put whatever they want behind the meter, the issue is going to be what they can actually export into the system.
The new guidelines limit small-scale rooftop solar exports to 5kW, which is the standard already for a number of networks across the NEM, and for others – including in some parts of Queensland, where there is a zero solar exports limit – it is an improvement.
RE: Why do we need rooftop solar export limits?
SJ: There are constraints on the (National Electricity Market) system at the moment, but as we fix some of those issues, the whole idea is … to update those export limits in the future. Those export limits should actually get reduced.
But for now, the 5kW limit aims to restrict how much they can export into the grid. The issue of the sizing of what they can actually build (behind the meter) is irrelevant.
RE: Will this impact consumers if they do happen to export more than 5kW?
SJ: If they are exporting too much, (some older systems without smart inverters) will switch off. It depends on the age of the unit.
(But) …we’ll be working with installers, to give the right information to customers on what to expect.
We’ve been engaging quite heavily with people like the Clean Energy Council to try and make sure that they are on board to drive that home.
RE: Are the networks trying to limit the amount of rooftop solar and battery storage that is installed on the NEM? Or are they trying to accommodate more?
SJ: That is actually the whole aim of the networks: how do we actually better facilitate more distributed energy resources into the grid? How do we solve those limitations in the best and most efficient way and look at new frameworks. How do we give customers better value from their system?
RE: Are the new standards – and therefore the export limits – compulsory for networks?
SJ: No, these guidelines are recommended for all NEM states. If networks go outside of these guidelines they’ve got to document that and justify it.
If for whatever reason… they’ve got extra constraints (long skinny rural feeders) and the hosting capacity is a little bit lower in that area. Or it could be an area where it’s fully meshed and there are no limits. If they are outside of those bounds, they need to explain.
RE: What’s the outlook for distributed solar on our grid?
SJ: This is actually evolving at a rapid rate, if we don’t solve this – it’s actually causing network issues already.
The whole idea is that the guidelines in themselves aren’t the panacea, but they are one of the tools that then helps us get more DER onto the system.
Each of these tools, we keep updating those, making them more and more granular, do this even better going forward.
RE: And what about for battery storage?
SJ: These documents will help explain what you need to do, not only for PV but for storage, regarding how we can best utilise storage for customers. How can they extract that value back out of the system? We can give signals to customers to export at different times. And that could be for the wholesale markets, for the constraints market, for demand response.
It could also be around community storage facilities – so instead of investing in your own home battery storage, you do it for the area. It will open up opportunities for thrid parties to use stored energy. It enables all those different options.
Darren Gladman, director Smart Energy, Clean Energy Council
RE: The ENA says these guidelines are all about making things easier and better for consumers, and – ultimately – paving the way for a lot more solar and battery storage to be added to the grid. Is this how the CEC sees it?
DG: The idea that there should be an overarching process – and that it should not just be left up to the individual Distribution Network Service Providers (DNSPs) is something we’ve been calling for for a long while. We like that part of the guidelines.
However, it’s still lacking the clarity that we were hoping would come out of this.
Also, we don’t like the idea of telling somebody that they can’t export (their excess rooftop solar) being the first solution, we think that should be the very, very last solution.
We would prefer to move to dynamic export limitations, but the system is not ready for that yet.
On the other hand, in terms of proposals requiring better capability from inverters, we generally support what’s being proposed. We recognise that’s going to enable much better hosting capacity on the network, so we see that as a worthwhile investment to enable that.
The other bigger picture issue the ENA document doesn’tt address – and it’s ok that they didn’t – is frequency response: New inverter capabilities and their ability to provide grid services. Currently there’s not a framework to recognise which of those services ought to be paid for and which, if any, are appropriate for the network to demand as a condition of connection.
There is no consideration of what ought to be remunerated, compared to being a condition of grid connection. So how does that undermine a market in future to provide these services? The AEMC tried to handball this issue to ENA to deal with, we’ve now put that back to the AEMC – it’s more in their remit.
Because if you assume that there’s going to be bits of the network that are going to be really high penetration DER, then at some point there does need to be a framework saying, ok, we don’t expect to get this service for free.
RE: You mentioned having standards for inverters – can you explain this further?
There’s two aspects for what they’re requiring from inverter, one is export limitations. The other is that the inverter is smart enough to sense conditions on the network – to sense that it needs to back off from exporting in the middle of the day, or needs export more power – this would only be something that systems would be required to do at times when the network was having voltage management issues.
Although that is an imposition on customers in a way – because on occasion it will mean that their ability to export is not as big as they might have been – (South Australian utility) SAPN reckon it would double the hosting capacity for their network.
RE: So who needs to know about these new guidelines?
DG: It’s not really an issue for consumers. If export limitation is brought in by the networks, there is an issue there of the amount of money you can make exporting to the network, but frankly we wouldn’t recommend people make a business case from exporting to the grid.
Otherwise, consumers can be confident their (CEC accredited) installer and their retailer get it – although there might be a new set of rules coming, and they need to be aware of what sets the rules.
If you sell solar systems, you probably need to be across this, for stock control – that is starting to become material. We want to see, as DNSPs adopt these guidelines, enough notification so that people aren’t stuck with old stock.
Inverter manufacturers, definitely you need to know this.

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