SA Newsflash – They’re Messing With Solar Today

An Industry update from SA Power Networks – That Should Go To Customers

AUGUST 22nd 2024

Be alert, but not alarmed. Solar customers in South Australia should be aware that SAPN is conducting some experiments today which might see your solar power being temporarily turned down or turned off.

If your solar inverter was installed under the so-called Smarter Homes programme, it may be connected to a dedicated circuit from your retail electricity meter or have an internet connection that allows SAPN to curtail solar production during grid emergencies.

During times of exceptional solar generation, combined with low overall demand (or possibly a network calamity) there’s simply too much electricity on the network. To keep everything under control some of this solar needs to be turned off.

Testing Times

As an electrician, I receive emails from my local Distribution Network Service Provider under the heading “Notice to Industry,” and most of them are pretty mundane.

This morning’s missive was more interesting, and it makes me wonder why it’s not more widely circulated.

Forget about planning. The message was that TODAY, they would be testing the “Smarter Homes” solar curtailment capability and that solar inverters may be down for no more than an hour.

As we head for Spring, when the clouds clear and fewer people are using energy hungry heating appliances, there’s a good chance that a sunny Sunday will produce the perfect conditions for 110% of state demand to be coming from our rooftops.

When the entire grid is effectively running in reverse, the authorities in charge get a little nervous about steering it. For 2% of the year they like to exert some extra control.

There’s Two Kinds Of Control

Introduced in 2020, the “Smarter Homes” program is proof that red tape is easily cut if somebody in authority gets scared enough.

It was a stopgap if we’re being honest, but a necessary backstop, followed by Queensland some years later.

Solar power installed under this programme is controlled in two ways. Some systems have your inverter connected to a dedicated contact in the retail meter. This is hilarious when the retailer cocks up the programming and pretends your inverter is a hot water service. Solar doesn’t work when switched on at 11:00 PM.

When they’re working correctly, these systems have a standard 5kW export limit. Once SAPN puts out the “bat signal” to curtail generation, your inverter switches off, and you revert to being a standard electricity consumer.

The more refined version of this control system still has a fixed 5kW export limit but uses an internet connection to throttle your inverter down. When SAPN send out the signal, it won’t export anything to the grid, but it still generates for you to use at home.

To the best of my knowledge, these are the systems being tested today.

Flexible Connections Are Better

Modern solar systems are designed to work in a similar fashion. Although it’s not available in all areas just yet, dynamic controls mean SAPN can turn your solar down when needed, but most of the time, it will be turned up so it can export its full capacity. These systems don’t have a standard 5kW export limit, but if there’s no internet available, a hard limit of 1.5kW is applied.

Don’t Ring Your Solar Installer Today

Hopefully, your system has some monitoring that’s already alerted you to an unexpected drop in solar output.¹ In the past, these events have caused installer phones to ring hot as people complain about what they perceive to be faults in solar power systems.

To be honest, I don’t know why SAPN seem to keep these things a secret; it’s a question I’m going to ask them.

The only surefire indication of a curtailment event in progress is having a Catch Control (formerly Catch Power Relay) installed as your consumption meter. Catch’s Monacle monitoring platform offers a real-time animation to show when solar is being throttled.

Switch It Off and On Again

If your solar doesn’t appear to be working tomorrow, it may need some attention. Next to your inverter, there should be a detailed label explaining the shutdown procedure.

The AC isolation is either a dedicated switch next to the inverter or a circuit breaker in the nearby switchboard. DC isolation is either a dedicated switch or breaker adjacent to the inverter or a knob on the side or bottom of the inverter itself. (If you have microinverters like Enphase, then there’s no DC to worry about)

Basically, turn the AC supply off first and then the DC supply off. Wait half a minute, switch them back on, and everything should be apples. If it’s not, ring your installer or contact Solar Quotes, and we’ll find you one.

Original Source: https://www.solarquotes.com.au/blog/sapn-newsflash-curtailment-testing/