SA Power Networks Limits Three-Phase Exports To 15kW

If you’re a South Australian who needs three-phase output from your solar power kit, I hope you’ve already made your application to SA Power Networks for approval, because from the end of May, new rules limit three-phase export in that state to 5kW per phase.

The change was foreshadowed: in April, SA Power Networks confirmed the export limits for three-phase solar inverters would be cut, and with the publication of its technical standard on May 30, that throttling has come into effect.

The change reversed a decision we discussed in December 2017. At that time, SAPN limited single-phase export to 5kW, but allowed 10kW per phase export on three-phase systems – as we put it at the time, “3 phase homes can fill their boots with 30kW of inverters and 40kW of panels”.

Those halcyon days are over for three-phase users – under the new technical rules, they’re subject a 5kW per phase limit, for a total of 15kW, in effect putting them in the same boat as single-phase owners. And, of course, that also halves the maximum customers can reap back for what they feed into the network – which would have been a savage hit if it applied retrospectively.

That, fortunately, is not the case. SA Power Networks emphasised that it only applies to applications for connection received after May 31.

“The new three phase limit applies to all applications after 31 May 2019 — noting there is a period of grace for applications received up to 31 May,”

a spokesman for the company told us in an e-mail:

“For applications received up to 31 May 2019,  the installation and connection must be completed by 30 August 2019 or a new SEG application will have to be made and the new three-phase export limits will apply.

“What we have done is apply the existing 5kW single phase export requirement to a three-phase installation. We are now aligned with the national guidelines developed after broad industry consultation, including with the Clean Energy Council.”

Why the limit?

SA Networks has two justifications for its decision – national standards, and the capacity of its own network.

In 2017, we noted the utility is following the AS4777.1 standard, but it does have wriggle-room to make exceptions – that’s one reason the 30kW export limit lasted so long.

In changing tack last month, SA Power Networks says the limitations of its own network, most particularly the “last mile” where the wires are thinnest (and, we suppose, oldest), have forced the change. Quoting from its April statement:

“The rapid increase in the installed capacity of inverter energy systems (IES) across South Australia into an electrical network originally designed for one way energy flow has presented a number of challenges to the safety and reliability of the distribution network.

“It is important to remember, every powerline has a finite capacity to accommodate the connection of solar and batteries, before technical issues arise. Remediation of these issues in some areas is uneconomic and is not in the best long-term interests of all cost sharing electricity customers.”

As previously, SA Power Networks also calls on the authority of national standards to justify its decision:

“This is consistent with Energy Networks Australia (the national industry association representing Australian electricity networks and gas distribution businesses.) releasing the National Distributed Energy Resources Grid Connection Guidelines on 7 March 2019. In preparing these guidelines, Energy Networks Australia (ENA) consulted broadly with industry including the Australian Energy Market Operator, the Australian Energy Market Commission, state and federal governments and the Clean Energy Council as well as each of the fourteen utilities across Australia.”

You’ll notice that there was very little consumer representation in those deliberations. The closest the consumer is to the consultation is the Clean Energy Council, which represents Australia’s solar energy industry. While we all have a stake in our customers getting the best deal, nobody is speaking directly for consumers, and that’s outdated in a world where customers are also electricity generators, and deserve a greater voice in discussing trade-offs that affect them.