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How does off-grid solar work, and what is in an off-grid system?

Checked and updated by our licensed electricians: October 2026

An off-grid system makes, stores and supplies all of a property’s electricity with no connection to the grid. The Australian Government describes these systems as completely self-sufficient: they need a large battery and a control system, and often a backup diesel or petrol generator for long cloudy periods. Designing one takes specific expertise, so here is how it works and what goes in.

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Home solar panels on a Colorbond roof in the Northern Rivers hinterland, installed by Sun Connect Solar

The parts of an off-grid system

  • Solar panels: they make power in daylight. Off-grid arrays are usually sized for the shortest, greyest days of the year, not the average.
  • A battery bank: stores the day’s solar for the evening, night and wet days. It is large, because there is no grid to fall back on.
  • Inverter and controls: turn stored and solar power into household power and decide what charges and what runs.
  • A backup generator (often): the government notes off-grid systems often include a diesel or petrol generator for long cloudy periods. Some battery systems are designed to work with one: Sigenergy’s manual describes a diesel generator working with its Gateway to give a smooth transition between solar, storage and generator power for long-term off-grid use.
  • Monitoring: an app so you can see charge, generation and loads and catch problems early.

How we size it

We start with what you actually run: fridges, pumps, tools, air-conditioning, workshop, and future plans. Then we size the panels and battery so you get through winter and a run of wet weeks, and decide whether a generator makes sense. The battery size question has its own guide: how many days of autonomy do I need?

What to expect day to day

  • Power is plentiful on sunny days, so heavy loads (washing, pumps, welders) are best run in the middle of the day.
  • Wet weeks need care: a battery cannot make power on a long grey stretch.
  • Without a grid there is no feed-in credit and no grid backup, so the generator and your habits matter.

Not sure you need to be fully off-grid? A grid-connected battery that keeps your home running in a blackout is often the better fit: see off-grid or grid-connected with a battery. Checks before you build: approvals and what to check in NSW.

More on our off-grid work: off-grid solar in the Northern Rivers and sizing an off-grid battery: days of autonomy.

Why locals choose us

  • Our own in-house team designs every system and does every install. 25 years in solar and large commercial electrical work. No subcontractors.
  • A face-to-face site visit before every install: compliant battery position, switchboard and RCBO check, no surprises on the day.
  • SAA-accredited installer and Sigenergy-approved, with a 25-year workmanship warranty on our installation work.

Questions we get asked

Does off-grid solar work in wet weather?

Panels still make some power in cloud, but much less. That is why off-grid systems are sized for winter and wet weeks, and often paired with a generator.

Do I need a generator?

Not always, but the Australian Government notes off-grid systems often have one for long cloudy periods. We decide with you from your loads and how much risk you accept.

Can I run a whole house off-grid?

Yes, if the system is sized for your loads. Large loads and starting currents need to be designed for, so tell us everything you run.

Who designs and installs off-grid systems?

Designing an off-grid system needs specific expertise. Ours are designed by our own team and installed by our own electricians.

Sources

Last checked 7 October 2026. Only the manufacturer’s, the network’s or the government’s own documents are used; app menus and defaults change between models and versions, so if your screen looks different, call us rather than guess.

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