Industry slams “antiquated, brutal” rooftop solar switch off plan for Sunshine State

A new rule that will require large numbers of Queensland rooftop solar systems to be fitted with “mid-20th Century” technology has been slammed by industry and peak bodies as outdated, reckless and likely to impose “significant extra costs” on consumers and installers.

Energy Queensland has revealed that from February 6, 2023, new and replacement rooftop solar and battery storage systems of 10kW and over will be fitted with a generation signalling device that will allow the state’s network operators to switch these PV systems off, remotely, if needed.

The generation signalling device, also referred to as “ripple control,” is Energy Queensland’s answer to the increasingly pressing problem of large amounts of daytime solar exports sending operational demand so low as to threaten system security.

It’s a problem that requires a relatively urgent fix, particularly in the context of historically glacial energy market reform. And particularly for the Sunshine State, where just over a month ago, operational demand hit a new record low as solar contributed 42 per cent of total energy demand across the National Electricity Market.

In South Australia, where rooftop solar surges towards brief moments of supplying the equivalent of 100 per cent of state demand, solar switch-off rules and enabling technologies have been in place in the state for two years, alongside solar export limits.

Western Australia followed suit a year later, in November 2021, to become the second state to allow the network operator to order residential rooftop solar systems to be switched off remotely as an emergency measure to keep the grid stable.

Smart vs dumb

But while South Australia and Western Australia have sought to solve the problem by making solar systems smarter and more visible to networks and the market operator via software solutions and the latest inverter technologies, Queensland – the country’s most coal dependent state – has opted to use comparatively ancient hardware.

As Energy Queensland itself says, the basic on-off device it plans to make mandatory for all new or upgraded solar systems over 10kW, has been used to manage system security on the state’s grid “for almost 70 years” – mostly to control load, such as hot water systems.

And in the context of what is a distinctly modern problem – what to do with all that ultra-cheap solar in the middle of the day – it is an approach that virtually no one in the renewable energy or solar and battery storage sector supports.

In a submission to Energy Queensland made during a notably brief consultation period, the Clean Energy Council says that while it understands the need for an emergency backstop mechanism, it “[does] not support the way Queensland proposes to implement” it.

“Energy Queensland is proposing a blunt approach of simply switching off solar PV arrays and battery storage,” the CEC submission says.

“Interoperability is the way of the future. Ripple control is a mid-20th century technology,” it says, pointing to the more modern cloud-based approaches already being used in South and Western Australia.

“The remote disconnect reconnect functionality has already been built by the industry for use in SA and WA. Queensland could simply be added to the platform,” the CEC submissions says.

Other key concerns flagged by the CEC and other submissions include the availability of the newly mandated hardware, the lack of consultation with consumers and the departure from what other states on the NEM are doing.

An untested and potentially costly process

Intellihub, whose submission is undersigned by a group of big-name solar inverter players including SMA, Fronius and Enphase, says the Queensland plans are “overly restrictive” and “out-of-step” with other states and likely to impose “significant unnecessary costs” customers.

The industry group warns that costs of the “outdated technology” could range from between $300 to $1,000 where additional configuration is required – a cost that will be passed on to the end consumer while also eating into the already tight margins of installers.

The group also warns, as does the CEC, that the technology, while fairly basic, is not proven to work solar and battery inverters, and could cause problems that will fall to the industry to rectify, including confusion and frustration among customers.

“This is an untested process,” says the CEC submission. “It might work perfectly every time but that seems highly unlikely, and it would be reckless to make that assumption.

“Turning off battery inverters will have unintended consequences for the use of batteries as backup sources of power,” it adds.

“The consultation paper does not provide a rational for switching off customers’ batteries as well as their solar PV array.”

An “antiquated and brutal measure”

Eddie Springer, the founder and CEO of major PV and battery installer Springer Solar, says in his own submission to Energy Queensland that the proposed backstop mechanism is “an antiquated and brutal measure.”

In additional comments from SolarEdge tacked on to Springer’s submission, the global inverter maker says rushing through such a mechanism is risky and “highly questionable.”

“Turning off an inverter in the middle of the day without any visibility by the network of the behind the meter load will not only stop any PV export, it will also introduce on the network all of the behind the meter loads that the system has been supplying,” SolarEdge says.

“This could bring about huge voltage and frequency fluctuations which could then cause the cascade tripping of other inverters and generators on the network.

“The risk here is significant and unjust when other more superior options of control not only exist but have been tried and tested and proved to function well already in Australia,” the submission continues.

“The proposal is also a very short-term solution that has no future proofing benefit.”

A February date is set

For its part, Energy Queensland appears to have made up its mind. On the Emergency Backstop Mechanism website here, it says that after considering feedback – consultation was launched in September – it has decided to go ahead with the mechanism as planned, from February 2023.

State government-owned network companies Energex and Ergon Energy have their own web pages – here and here – supporting this decision and explaining which inverter connections are required to install a the mandated hardware from the February date.

What industry players like Springer would like to see from the state government energy companies is more time, more consultation and more options.

“For companies like us… we’ve got jobs sold six months into the future and they’re bringing in a new requirement that we’ve had no time to plan, no to time to cost, and no time to test.”

Springer says the other major concern of industry is the knock-on effects that this blunt instrument might have on their customers’ systems, some of which might have multiple inverters and finely tuned smart energy controls in place.

He says there has been no guarantee that customers will know what is happening when their solar systems are suddenly switched off, and no testing to reassure industry that systems will switch back on seamlessly.

Springer says that a scenario where customers are panicked by the switch off, or their systems don’t come back online properly, could wind up adding new cost and labour pressures to businesses that they simply cannot absorb.

“There’s got to be a better way,” he tells One Step Off The Grid. “We’re using technology from the 50s. There’s got to be a better way than a big red button that just goes bang and just shuts everything down.

“We want more time and more consultation; and reassurance that they will be using this backstop as an absolute last resort,” Springer says. “It can’t be the first control mechanism we implement.”

For more news on our RenewEconomy sister site, click here. And listen to the latest Solar Insiders Podcast: The dumb decisions holding back rooftop PV, here.