Can all solar homes become smart energy hubs? On paper – absolutely! IRL, a few hurdles remain

Can a regular solar home be programmed and kitted out to allow for hands-off energy generation, storage, export, and optimisation without the need for regular consumer intervention or major system upgrades?

The base technology might be there, but the standards linking them all together aren’t, according to the findings from the second RACE 2030 report into a SA Power Network multi-year ‘Energy Masters’ project.  

The $13.8 million project is subsidising electric appliances from smart split-system air-conditioners, heat pump hot water, and smart EV chargers, along with a home energy management system (HEMS) to help 500 households optimise their home energy use.

And it’s looking at all of the ways this does and – given current tech – doesn’t work.

With 100 of the 500 homes fully kitted out by September last year, the second ‘lessons learned’ report to the Australian Renewable Energy Agency (ARENA) shows where work needs to be done to create a Jetsons-style home of seamless energy prosumerism.  

For a start, more than half of the 2000 households that wanted to join the trial couldn’t, because their homes had existing solar systems with inverters that couldn’t talk to the management software chosen by SA Power Networks for the project.

“This incompatibility highlights the urgent need for national interoperability standards to ensure HEMS, smart appliances, retailer APIs, and network systems can communicate seamlessly to unlock scalable, open ecosystem,” the RACE 2030 report says. 

Oddly enough, part of the challenge was also learning that many people don’t actually know what their appliances are, with air conditioning being a real point of confusion. 

“Many households struggled to correctly describe their system types, particularly with air conditioning,” SA Power says. 

“The colloquial term ‘split system air-conditioning’ was originally assumed to be unambiguous, but site visits revealed that several households describing their system as ‘split’ in fact had ducted units, which are not currently compatible with the HEMS used in this project.”

This created real problems because some households had to wait months only to find out their homes weren’t eligible.

And while 70 per cent of the 100 households have made the choice to ditch gas hot water for electric, SA Power has had to do some educating there too.

It’s had to teach its trial households that their hot water is now limited to their tank size and that heating is not instantaneous, but that they can match the power demand to their routine. 

How many people does it take to change a light bulb?

SA Power Networks had hoped to be further ahead than just 100 households by now, but creating Jetsons’-like homes from scratch has run into hurdles — much like those around education.

Using a physical, rather than a more futuristic virtual home management system also sent the project on an unexpected journey – it’s taking a lot longer to fit homes out with a physical device, up to four hours on average, than doing this remotely. 

It’s a situation that compares to the old joke, how many people does it take to screw in a lightbulb?

The answer – in SAPN’s case study – is an electrician, a plumber and software techs, who now all need to work together to ensure the home management system can control the proverbial lights. 

Australia will need more plumbers who can work with electrical hot water, more electricians happy to handle digital device installations, and more tech support for all of the above to ensure they can talk to the software in control, SA Power says.

Who does the home listen to?

Part of the deal is that homes in the trial have to sign up to a tariff that gives them a whopping 33c/day rebate in exchange for letting the DNSP occasionally tell certain home appliances to dial back their electricity use, when the grid is congested.

But before SA Power could get that far, it had to solve this issue first: who does the home listen to?

The home management system controls the behind-the-meter energy use. 

The retailer, in this case Amber Electric and EnergyAustralia, are sending signals via dynamic tariffs about how they want the house to use electricity from the grid. 

And the distribution network service provider (DNSP) wants to have oversight, and at times some control, over how the house interacts with the grid.

Figuring out which of these takes priority and when is a learning curve, the report says. 

“The Project has built and demonstrated how HEMS technology can enable multi-layered optimisation for behind the meter, network and retailer benefit, while all being governed by customer preferences,” it says.

“It has also been identified that open interoperability is a key barrier to enable rapid and broad adoption of this technology at scale.”

The outcome is that the DNSP can talk directly to the home management system when the grid is under pressure and tell it to reduce the amount of electricity a hot water system is using, or to use the home battery to reduce the house’s demand on the grid.

So far, so Jetsons, but what SA Power has found is that it can’t do this automatically.

Right now, it has to manually talk to the retailers in a process that is “resource-intensive and not scalable.”

“Future scalability will depend on integration with Market Settlement and Transfer Solutions (MSATS), which was not feasible for this trial, as the intent was to first learn from the Project to inform the most effective approach, and/or the development of a standardised DNSP tariff credit mechanism,” it says.

If you would like to join more than 28,000 others and get the latest clean energy news delivered straight to your inbox, for free, please click here to subscribe to our free daily newsletter.