Western Australia opened consultation on Wednesday on a safety standard for plug-in solar panels and batteries, which would make it the first state or territory in the country to legalise the technology. "Balcony solar", as it is known in Europe, is used by millions of households there and in the UK. In Australia it has simply been unlawful.
The systems are what they sound like: one or two panels on a balcony rail or in a backyard, an inverter, an ordinary plug, an ordinary socket. No electrician, no roof, no application. The power flows in behind the meter and offsets whatever the fridge and the air conditioner happen to be drawing.
That is the appeal and the difficulty at once. Anyone renting, or living in an apartment with a balcony, has no reason to spend thousands on a roof they do not own. The Western Australian government estimates a typical plug-in system saves a household about A$240 a year, and up to A$500 with a plug-in battery. The advocacy group Solar Citizens puts the figure at A$300–400, doubling with storage. Upfront cost runs to about A$1,300 plus extra for a battery, according to the ABC, with payback periods that industry experts put at four to ten years. And unlike a roof array, the panels move house with you.
"For too long, the benefits of cheap solar have been out of reach for anyone who doesn't own their roof. That isn't fair," said Energy and Decarbonisation Minister Amber-Jade Sanderson. "Millions of European households already use these systems every day, and WA families should be able to do the same."
The substance of the consultation, though, is unglamorous and decisive: how to stop a wall socket being overloaded. A balcony panel backfeeds through existing household wiring that other appliances may already be loading. And if the grid drops out, the inverter has to shut down, or it will energise a cable a technician believes is dead. Germany's VDE rules — which Golem reports WA is explicitly modelling the standard on — cap inverter output at the 800-volt-ampere class, specify the connection hardware, and require grid monitoring that disconnects on fault.
Germany being the reference is not politeness. Roughly one household in ten there runs such a system, and the norms have been hardened against a decade of real installations. The UK legalised plug-in solar earlier this year; New Zealand is looking at doing the same within twelve months. Australia's energy ministers agreed in September to explore a safe national rollout; WA has now moved first.
The grid operator is the quiet third party at the table. In the South West Interconnected System, the state's main grid, more than 40% of homes already have rooftop solar. The easy capacity is taken. What remains is the households without a roof — and generation behind the meter that the operator cannot see, let alone curtail.
Two things still have to happen before a panel goes on a railing. The state government will need to bring landlords and body corporates along, or the permission stays theoretical. And the connection rules have to follow: authorities have signalled that requirements for solar and batteries will be updated, including alignment with Australia's CSIP-AUS standard for controllable devices. The open question is whether a fleet of small inverters will be welcomed onto the grid or merely tolerated by it.
