Genuine Independence Looks Different to Grid-Connected Solar

Western Australia has one of the largest and most sparsely populated electricity networks in the world, which makes off-grid power a genuinely practical option, and in some cases a free one, for regional and remote properties rather than a niche lifestyle choice.

What “Off-Grid” Actually Means, and When It’s the Right Choice

Off-grid means a home generates and stores all its own power with no connection to the mains network at all, a fundamentally different proposition to a grid-connected home with solar and a battery. It generally only makes financial sense where a grid connection would be prohibitively expensive or unreliable in the first place, remote rural blocks far from existing power lines, rather than as a lifestyle choice for a home that could otherwise connect cheaply. For most WA households within the South West Interconnected System, staying grid-connected with solar and a battery, covered in our Home Electrification guide, delivers similar independence with far more redundancy.

WA’s Stand-Alone Power System (SPS) Program: A Free Alternative Worth Checking

Before assuming you need to fund an off-grid system yourself, check whether your property qualifies for Western Power or Horizon Power’s Stand-Alone Power System program, which replaces an unreliable or expensive-to-maintain grid connection, typically on isolated lines or fringe-of-grid properties, with a solar, battery and backup generator system the utility owns, installs and maintains at no cost to the customer. Thousands of these systems have already been rolled out across regional WA, and eligible customers pay the same tariff they would on the standard network. It’s worth contacting your network operator directly to check eligibility before pricing a private off-grid system.

Sizing an Off-Grid System for Genuine Independence

Unlike a grid-connected system, where a battery just needs to cover evening use until the grid takes over, an off-grid system needs to be sized for your worst-case scenario: several consecutive overcast winter days with no generator backup available. This generally means significantly more solar capacity and battery storage than a grid-connected home would need for the same household, since there’s no fallback if the sizing is wrong. A proper off-grid design starts with a detailed audit of your actual and seasonal energy use, not a rule of thumb, since underestimating capacity is far more costly to fix after installation than before.

Backup Generators: The Practical Reality of Off-Grid

Almost every genuine off-grid system, including WA’s utility-run Stand-Alone Power Systems, includes a backup generator for the days solar and battery alone can’t cover, even though the goal is for the generator to run as little as possible. Well-designed systems in WA’s SPS rollout achieve well above 90% renewable generation, with the generator as a genuine last resort rather than a routine backup. Sizing the solar and battery generously enough to keep generator runtime low is worth the extra upfront cost, both for lower running costs and because a generator that’s constantly cycling wears out faster and needs more maintenance.

Australian Standards and Compliance for Off-Grid Systems

Off-grid systems in Australia are designed and installed to AS/NZS 4509, the standard covering stand-alone power systems, alongside general electrical safety standards under AS/NZS 3000. Even though an off-grid system isn’t connected to the network, it still needs to be installed by a licensed electrician and, depending on the system, may need to meet Clean Energy Council accreditation standards to remain eligible for any applicable rebates or insurance requirements. This isn’t a space for DIY beyond genuinely small-scale systems.

Costs and Trade-Offs of Going Off-Grid by Choice

Choosing to go off-grid on a block that could otherwise connect to the mains grid is almost always more expensive upfront than a grid connection with solar and battery, since you’re paying for enough capacity to cover the worst case rather than relying on the grid as backup. It can make sense for genuinely remote blocks, or where connection costs are extreme, but for most WA homeowners within reasonable reach of the network, the practical benefits of independence are better achieved by maximising self-consumption on a grid-connected system than by disconnecting entirely.

For grid-connected solar and battery sizing, see our Home Electrification & Renewable Energy guide.