Solar panels produce direct current. An inverter turns that into the alternating current a home uses. How that conversion is arranged is one of the real design choices in a solar system. It comes down to three approaches: a string inverter, microinverters, or power optimisers paired with a string inverter. This guide explains how each works, the genuine pros and cons, and which tends to suit a Perth home. A household can then understand what is behind a quote rather than just a brand name.
The short version is that all three are proven technologies. The best choice depends on the roof. For most Perth homes, a quality string or hybrid inverter is the sensible core of the system. Panel-level electronics are best reserved for situations that genuinely call for them.
String Inverters: The Established Standard
A string inverter is a single inverter, usually mounted on a wall near the switchboard. It converts the output of a whole string of panels at once. It is the most established and widely installed approach in Australia. Modern string inverters are efficient, reliable and, increasingly, hybrid, meaning they are ready to add a battery.
Its strengths are simplicity, cost-effectiveness and serviceability. There is one main unit doing the conversion. It is easy to monitor and, if it ever needs attention, easy to access at ground level rather than on the roof. Its one limitation is that panels are connected in a string. Heavy shading on one panel can pull down the output of others on that string. On an unshaded Perth roof, which is common, that limitation rarely comes into play.
Microinverters: Conversion at Each Panel
Microinverters take the opposite approach. A small inverter is fitted under each individual panel. The conversion from DC to AC happens at the panel itself. Because every panel operates independently, shading or an issue on one panel does not drag down the others. Each panel can be monitored individually.
That independence is the main advantage. It is most valuable on a complex or shaded roof. The trade-offs are cost, which is typically higher. The electronics sit on the roof under the panels. There are many more units in a harder-to-reach location rather than one accessible unit on a wall. Microinverters also shape a home battery options. They convert power to AC at each panel. Any battery added must be AC-coupled. This rules out the more efficient DC-coupled storage a hybrid string inverter allows.
Power Optimisers: A Middle Path
Power optimisers are a hybrid of the two ideas. A small optimiser is fitted to each panel to condition its output at the panel level. The actual DC to AC conversion is still done by a single string inverter on the wall. This delivers much of the panel-level benefit, such as reducing the impact of shading and allowing per-panel monitoring. It keeps one central inverter.
A useful feature of some optimisers is that they can be deployed selectively rather than across a whole roof. Brands such as Tigo are agnostic to the inverter. Their optimisers can be added to a standard string inverter. They are fitted only to the specific panels affected by shading. The rest of the array stays as a normal, cost-effective string. This targets the problem exactly where it exists. It avoids the expense of optimising every panel on the roof.
Like microinverters, optimisers add panel-level electronics on the roof and add cost. They suit roofs where shading or complex layouts make per-panel management worthwhile. On a simple, unshaded roof, they add expense for a benefit the roof does not need.
Side by Side
| Factor | String inverter | Panel-level (microinverters or optimisers) |
|---|---|---|
| How it converts | One central inverter for a string of panels | Electronics at each panel |
| Shading tolerance | Best on unshaded roofs | Handles shading and complex roofs better |
| Monitoring | Whole-of-system, with per-panel available on some | Per-panel by default |
| Serviceability | One accessible unit at ground level | Many units on the roof under the panels |
| Battery options | Hybrid models allow efficient DC-coupled batteries | Microinverters are AC-coupled only; optimisers keep hybrid options |
| Relative cost | Lower | Higher |
Which Is Right for a Perth Home?
The honest answer is that it depends on the roof. This is where good design matters more than any single technology. A great many Perth homes have simple, well-oriented roofs with little or no shading. On those a quality string or hybrid inverter delivers excellent performance. It offers straightforward monitoring. It provides an easy path to a battery. It gives the best value. Where a roof is genuinely complex, split across several angles, or affected by shading from trees or neighbouring buildings that cannot be designed around, panel-level electronics earn their place. They keep each panel productive.
The mistake is treating one approach as universally best. The right question is not which technology wins in theory. It is which suits a specific roof. That is a design decision, not a slogan.
What Positive Energy Solutions Installs
Positive Energy Solutions builds systems around quality string and hybrid inverters from Fronius, Sungrow and SigEnergy. They suit the majority of Perth roofs. They provide a clean, battery-ready path for a home that wants storage now or later.
Where a roof has real shading, Positive Energy Solutions deploys Tigo optimisers selectively. It adds them to the string inverter on only the specific panels that need them. Because Tigo optimisers are agnostic to the inverter, this keeps a proven string or hybrid inverter at the heart of the system. It solves shading exactly where it occurs, rather than optimising a whole roof that does not need it.
Positive Energy Solutions does not install microinverters. They convert power to alternating current at each panel. They limit a home to AC-coupled batteries only. The string and hybrid inverters Positive Energy Solutions uses keep the more efficient DC-coupled battery path open. Every system is matched to the home during the design stage. It is installed by our accredited installers and signed off to Positive Energy Solutions’ completion standards. It is backed by a 10-year installation workmanship warranty and Positive Energy Protection, powered by Omnidian.
Frequently Asked Questions
Are microinverters better than a string inverter?
Neither is universally better. They suit different roofs. Microinverters handle shading and complex roofs well because each panel works independently. But they cost more and sit on the roof. A quality string or hybrid inverter is efficient, cost-effective, easy to service and battery-ready. It suits the many Perth homes with simple, unshaded roofs.
What is the difference between a microinverter and a power optimiser?
A microinverter converts DC to AC at each panel. The conversion is done entirely on the roof. A power optimiser conditions each panel’s output at the panel level. It leaves the actual DC to AC conversion to a single string inverter on the wall. Both give panel-level benefits such as shading tolerance and per-panel monitoring.
Do I need panel-level electronics for my roof?
Only if the roof calls for it. On a simple, well-oriented and unshaded roof, a string or hybrid inverter performs excellently. It offers the best value. On a roof with significant shading or several different angles, microinverters or optimisers can be worthwhile. A proper design determines which suits a particular home.
Can I add optimisers to a string inverter?
Yes. Optimisers such as Tigo are agnostic to the inverter. They can be added to a standard string inverter. They can also be deployed selectively. They are fitted to only the panels affected by shading rather than the whole array. This solves a shading problem while keeping a cost-effective string system on the rest of the roof.
Do you install microinverters?
Positive Energy Solutions does not install microinverters. They handle shading well. But they convert power to AC at each panel. This limits a home to AC-coupled batteries only. Positive Energy Solutions uses quality string and hybrid inverters that allow the more efficient DC-coupled storage. It deploys Tigo optimisers selectively where shading needs addressing.
Which inverter type is best for adding a battery?
A hybrid string inverter offers the simplest battery-ready path. It is designed to add storage directly. Panel-level setups can work with batteries too. The arrangement depends on the system. For a home planning storage now or later, a hybrid inverter is often the cleanest option.
Get the Right Inverter for Your Roof
The best inverter approach is the one matched to a specific roof, rather than the one with the loudest marketing. Working that out for a particular home is exactly what a Positive Energy Solutions system design is for.
Talk to the local team about the right system for your Perth home: request your quote from Positive Energy
About the Author
Jason Wiktorowicz
Sales Manager, Positive Energy Solutions | Perth, WA
Jason has been at the centre of Western Australia’s energy transition for over a decade. He was Orchestration Lead on Project Symphony, WA’s largest virtual power plant pilot. He was Stream Lead on Project Encore. He worked directly with AEMO, Western Power and Energy Policy WA. He shaped how distributed energy resources connect and operate on the SWIS. That work included developing and rolling out CSIP-AUS, now mandatory for all new WA grid connections. He also led Emergency Solar Management, the first program of its kind in WA. He led VPP for Schools, which provided direct market benefits through Supplementary Reserve Capacity. He led REBAR, the WA Residential Battery Rebate scheme.
At Positive Energy Solutions, Jason leads sales with a focus on system design accuracy and long-term performance. Positive Energy Solutions installs solar and battery systems, EV chargers and heat pumps. It holds partner accreditations with Fronius, SigEnergy, iStore and SunPower.
10-year installation workmanship warranty. Positive Energy Protection, powered by Omnidian, performance monitoring included on all systems.
