Microinverters or optimisers for a shaded roof?
If your roof has shade, you'll probably be quoted one of three set-ups: a standard string inverter, a string inverter with optimisers, or microinverters. Here is how to tell which one your roof actually needs.
The short answer
- String inverter: cheapest. Fine when the roof is mostly clear.
- Optimisers: a box on each panel plus a string inverter. Helps a partly shaded roof, often cheaper than microinverters.
- Microinverters: every panel works on its own. Best for complicated or patchy shade.
Why shade matters more on a string
On a standard string inverter, panels are wired in a chain, and a shaded panel can drag down the output of the whole string[1]. Modern panels handle shade better than older ones, so the effect is smaller than it used to be[1].
Optimisers
An optimiser is fitted to each panel and works with a normal string inverter. It can boost output in a partly shaded system, and an optimiser set-up is often still cheaper than microinverters[2].
- Good for: a roof where a few panels get shade at certain times.
- Also gives: panel-by-panel monitoring on most systems, so a faulty panel is easy to spot.
Microinverters
A microinverter sits on each panel and turns its power into household power on the spot, so each panel works independently. That makes them a good option when some panels are shaded at times[2].
- Good for: roofs split across several faces, or shade that moves across the roof during the day.
- Check: how a battery would be added later, since some batteries pair more simply with a hybrid string inverter.
When a plain string inverter is fine
If the shade only touches the roof early or late in the day, or the panels can go on an unshaded face, a string inverter is usually the better value. On our calculator, even heavy shade cuts the yearly saving of a well-sized system only a little[3], so extra hardware has to earn its cost.
What to ask the installer
- Show me where the shade falls, and when.
- How much more output do you expect from optimisers or microinverters on my roof?
- What do they add to the price?
- How would I add a battery later with this set-up?
Why two quotes for the same job can be thousands apart
Installers price the same system very differently. These are the installed price ranges our calculator works from, before rebates: the low end is what a competitive installer charges, and the high end is what a poor quote looks like.
| System | Competitive quote | Poor quote |
|---|---|---|
| 6.6kW solar system | $8,000 | $10,000 |
| 10kWh battery | $7,650 | $13,500 |
| About 15kWh battery | $12,100 | $18,000 |
- The gap usually comes from margin, the brand of panel, inverter or battery, and extras such as a switchboard upgrade or backup circuit, not from a better install.
- Get at least two or three quotes, and ask for each to be itemised: hardware brands and models, size, rebates taken off, and anything extra.
- Compare batteries on price per usable kWh, not the headline price.
Get the numbers for your own home
Two minutes of questions about your bill, roof and routine gives you the system size, what it should cost after rebates and what it saves. Your report shows on screen straight away, and no installer sees anything unless you ask.
Run my numbers, freeCommon questions
Are microinverters better than optimisers?
For patchy or moving shade, or a roof split across several faces, often yes. For a few shaded panels, optimisers usually do the job for less.
Do I need optimisers if only one panel is shaded?
Not always. Moving that panel to a sunnier spot, or leaving it out, can be cheaper. Ask the installer to show the difference in expected output.
Can I add a battery to microinverters?
Yes, but usually with an AC-coupled battery that has its own inverter. Check the plan before you buy.
Sources
- CHOICE, How can you tell if your solar panels are working?. Read 4 November 2026.
- Your Home (Australian Government), Rooftop solar: microinverters let each panel operate independently, suiting periodically shaded panels; optimisers can boost output in partially shaded systems and are often cheaper than microinverters. Read 4 November 2026.
- Aussie Solar Info, How the calculator works: shading cuts modelled generation by 10% for some shade and 28% for heavy shade; solar-only scenario on a $500 a quarter bill, about 20kWh a day, run 4 November 2026. Read 4 November 2026.