Energex PeakSmart scheme sees 102,000 Queensland homes’ aircons capped at 50 per cent capacity five times in two months

More than 100,000 Queensland households have had their aircon’s capacity capped by the state five times since Christmas. But its neighbouring state isn’t following suit. Find out why.

The state has taken control of airconditioners in more than 100,000 Queensland homes five times since Christmas, but questions have emerged about whether these Big Brother-style interventions actually ease pressure on the electricity grid.

NSW has abandoned early-stage plans to follow the Sunshine State into remotely cutting power to aircons when demand surges after discovering the “true energy reduction … is far lower than expected.”

NSW authorities proposed adopting an Australian standard which would have mandated that “air conditioners installed under the (state’s) Peak Demand Reduction Scheme (PDRS) have internet connectivity and the ability to be controlled by a demand response aggregator.

The aim of the rule change was “to increase adoption of demand response capability through the PDRS, with a long-term outcome that all airconditioning users have the option to take part in demand response programs.”

Aircons in the scheme would receive messages sent by a power distributor to reduce “compressor power input to a percentage of the rated input power”.

Queensland Deputy Premier Jarrod Bleijie has previously criticised aircon capping. Picture: Supplied

In their position paper, NSW authorities noted “South Australia and Queensland adhere” to the standard under consideration, AS4755. However, “we have determined that the standard’s limitations make it unviable for the PDRS.”

The limitations included “the low certainty of energy reduction”.

“The standard outlines communication by reducing compressor power input to a percentage of the rated input power,” the authorities sad. “A CSIRO case study has shown that because most air conditioners run at a partial load, even on very hot days, and that the true energy reduction for AS4755 is far lower than expected,” the NSW authorities said.

The CSIRO study was brought to light by energy market expert Martin Gill, in a submission he made on SA’s plans to take control of aircons.

In his submission, Dr Gill said the CSIRO had found that even when it was exceeding 35 degrees Celsius outside, an aircon cooling a thermally inefficient room was able to operate below 50 per cent capacity most of the time.

So when a signal was sent to halve the aircon’s capacity, the demand reduction was negligible.

Queensland government-owned power distributor Energex capped as many 102,166 aircons in the state’s southeast at 50 per cent of their capacity on the afternoons of December 27 and 28, as well as on January 22, 23 and 24.

The “Demand Response Mode” (DRM) 2 interventions, which mostly started at 4.20pm and lasted 2.5 hours, were “a result of extreme weather”, Energex said, although data suggests temperatures remained below 35 degrees in most areas on these days.

The biggest reduction in electricity use on December 28, when the estimated benefit, according to Energex, was 47 megawatts – equal to the total one-day consumption of about 4500 homes.

The throttled aircons were enrolled in Energex’s PeakSmart program, which pays upfront rebates of $400 to consumers.

Energex recoup PeakSmart costs via all customers’ bills. Rebates have been received for as many as 155,000 airconditioners.

Dr Gill, who strongly supports the concept of demand response, said: “Paying people for not delivering anything is just a silly way of running a market.”

Still, Energex express confidence in its estimates, saying they were “calculated based on comparison of actual consumption data.”

In December, the then acting Jarrod Bleijie said it was “unacceptable” that Energex was turning people’s aircon’s off.

Martin Gill’s research has raised questions about PeakSmart’s effectiveness. Picture: Richard Dobson

That was before questions were raised about whether the interventions were actually reducing pressure on the grid.

The office of Energy Minister David Janetzki was asked whether the government would initiate a review into the effectiveness of the PeakSmart scheme, however it declined to respond.

Dr Gill, who until recently was the Consumers Federation of Australia on several Standards Australia working groups, told the Courier-Mail that rather than turning off aircons or cutting their capacity, the better option was to slightly increase the set temperature to a level that was still comfortable.

This, he said, was what products such as Google’s Nest Thermostat already do to help people minimise cooler running costs.

There would be greater acceptance from the public and more certainty that demand was actually being reduced.