Australia is a world leader in household solar, but the benefits of rooftop renewables are unevenly distributed – and many of the 2.5 million people living in apartments or units are missing out.
About 39% of Australians living in detached or semi-detached houses have solar, compared with 6% of those in apartments or units, research by Energy Consumers Australia (ECA) finds. A gap also exists in the take-up of batteries, installed in 7% of houses but only in 3% of apartments or units.
Ashley Bradshaw, ECA’s executive manager for advocacy and analysis, says “the research is pretty clear that most of the solar we have on homes today is on stand-alone homes”.
That’s because there are several hurdles facing apartment dwellers, he says, such as navigating the use of shared roof space and common areas, body corporate rules and electricity metering. Some households may face additional barriers, such as being renters or on lower incomes.
Kate Nicolazzo, the director of the social change agency Let Me Be Frank, says installing solar on an apartment building is “just a completely different kettle of fish” compared to a house, with added complexities related to governance and group decision making.
“It is absolutely doable, but it is not necessarily easy,” she says.
But for those considering the option, it’s a good time to do so, with new technologies on offer and generous incentives in New South Wales, Victoria and the Australian Capital Territory.
One roof, many homes
When it comes to solar system designs, there are usually two main setups for apartment buildings: directly connected systems involving multiple solar systems and separate inverters wired to individual flats, or shared systems where the electricity generated from a single solar installation is shared equitably among dwellings or used to power common areas like lifts, foyers and gyms.
“The historical challenge of solar on apartments has been – you’ve got one roof, and then you’ve got each apartment with their own electricity meter, and hence connection to the grid,” says Allume Energy chief executive and co-founder Cameron Knox. “But that, as you can probably imagine, gets cumbersome pretty quickly.”
The Melbourne-based company was founded with the goal of helping people in apartments access the benefits of solar and batteries. It developed a technical solution called SolShare, which enables the power produced by a shared solar system to be split among several apartments, without the added complexities of multiple installations, individual inverters and wiring.
SolShare works like a “traffic controller for solar”, Knox says, allocating the energy in a way that maximises savings to all, while ensuring every home gets their fixed allocation over the month.
“So if, for example, we’re neighbours in an apartment building and I switch the kettle on whilst you go out to walk the dog, I’ll get proportionally more of my solar allocation at that point in time than you will. Then you might get home, put your microwave on and be prioritised above me to back up. So every 200 milliseconds it makes new decisions on where should solar go to ensure everyone gets their fair share, but gets it at a time which maximises their savings.”
SolShare works behind the meter, in the same way as a rooftop system on a house. Residents need a smart meter to export excess solar to the grid, but remain free to choose their own electricity retailer.
It can be complicated, but there are also benefits, Knox says. Most apartments in Australia are lower rise buildings, the average being about 12 units. “These buildings often have plentiful roof space for solar, but haven’t had an effective way to deliver that to the apartment residents,” he says.
“Because they’re naturally a little bit higher than their stand-alone home counterparts, there’s less shading challenges and they can get really unobstructed roof space to generate energy.”
In Australia, Allume has connected more than 6,600 apartments to solar, and nearly 11,000 worldwide.
Other types of technologies, including small, plug-in systems known as “balcony solar”, are gaining popularity overseas, particularly among renters. But uptake in Australia has been limited due to electricity safety rules and metering.
Working together
Nicolazzo says the other big challenge for people in apartments or units relates to the way decisions about common property – such as rooftops or outdoor areas – are made under a strata association or body corporate.
Owners corporations and property managers can introduce administrative hurdles and other barriers, from voting thresholds and bylaws that make agreement challenging, or discouraging capital expenditure on shared infrastructure.
Some states, like Victoria, require agreement from 75% of owners for certain types of decisions related to common property, she says. That requires people to talk with their neighbours, which takes time and patience. It can be a lonely process without support, Nicolazzo says.
“I think if you are going to go through that process, find a friend within your building, [that] you can actually work alongside so you feel like you’re part of a team.”
It’s important to be aware that in multi-storey buildings, other complexities and unexpected costs can arise during installation, like a roof needing to be repaired or a switchboard upgraded. Embedded networks, where apartments operate on a private electricity network with one main connection, often pose another layer of complication.
There are several how-to guides to help with getting started, including resources published by Yarra Energy Foundation, Port Phillip city council, High Life Living and the Victorian government.
Other ways to save
Apart from solar, there are a lot of other opportunities for people in apartments to save money on energy, Bradshaw says. They can consider switching to a different electricity plan, shifting to electric appliances, and there are plenty of smaller, lower-cost options for reducing energy use.
“There are lots of ways you can look to save money on your electricity bill,” he says. “Its basically about thinking what’s best for your circumstances.”
