The short answer
What a solar inverter is, and why it matters more than the panel
Solar panels get all the attention, but the inverter is where the real decisions sit. It is the part that converts your panels' DC into usable AC, the part that caps how much power you can actually use, the first part to fail, and the part that decides whether you can add a battery later without tearing things out. Yet most buyers compare panel brands and accept whatever inverter is bundled into the quote. This page explains how to size an inverter, when each type wins, and why a "matched" inverter is often worse value than an undersized one.
Here is the core takeaway in one line: the inverter, not the panel, is where solar systems actually fail and where your real choices live. It converts the DC your panels make into the AC your home and the grid use, and that conversion caps your usable output: a 5 kW inverter can only ever push 5 kW of AC, no matter how many panels feed it. It is also the short-lived part, around 10 to 15 years against 25 for the panels, so it is the component you are most likely to replace. And the type you choose, string, micro or hybrid, decides whether you can add a battery later without ripping things out. The right question is not "which panel?" but "is this inverter sized, typed and built for the next 25 years?"
Reframe the assumption: a quote with a "matched" 6.6 kW inverter on 6.6 kW of panels looks tidy but is often worse value than 6.6 kW of panels on a 5 kW inverter. The smaller inverter is cheaper, claims the same rebate, and the deliberate oversizing of the panels (the 133% rule) flattens your generation curve and lifts self-consumption. The "matched" system pays for inverter capacity you only touch for an hour at noon.
Interactive explainer
What size inverter should you pair with your panels?
Set your panel array size and a target DC:AC ratio. We recommend an inverter AC size, snap it to a common rating, show the ratio you actually hit and the small clipping loss, then give a plain verdict. Or read your real rooftop to start from the array your roof fits.
Read your roof's maximum array (optional)
Nothing is stored. You can skip this and just use the sliders.
Recommended inverter
kW AC
Illustrative only. The recommended inverter snaps your exact figure (array ÷ ratio) to the nearest common AC size (3, 5, 6, 8, 10, 13 kW). Clipping is estimated from how far the ratio exceeds about 1.2 and stays small at sensible oversizing. Above 1.33 you lose full-rebate eligibility. Real sizing depends on orientation, shading and your inverter brand. Sources: Clean Energy Regulator, Clean Energy Council, AS/NZS standards.
The blind spot
Why most inverter guides give you the wrong picture
Most articles about solar inverters do three unhelpful things, and each one quietly costs buyers money.
First, they treat the inverter as an afterthought. They spend pages on the panel and then bolt on a paragraph that says "and you need an inverter too". That gets the priority backwards. The panel is the cheap, commoditised part that lasts 25 years. The inverter is the active part that does the work, fails first, and caps your output. It deserves the harder look, not the footnote.
Second, they list six inverter types as if you must choose between all of them. In a normal Australian home the real choice is narrow: a string inverter, microinverters, or a hybrid if a battery is coming. Off-grid and grid-tie distinctions matter only at the edges. Padding the list out to six types makes the decision feel harder than it is and hides the two or three factors that actually decide it.
Third, they call an undersized inverter a defect. Older guides warn you to "match" the inverter to the panels. In 2026 that advice is wrong. Deliberately running the panels above the inverter rating, up to 133%, is standard best practice, because it lifts the power you can use while costing you almost nothing in clipping. A guide that tells you to match is steering you toward worse value.
How inverters really shape your system
Expert analysis: the machinery behind the choice
The 133% rule: why clipping is a feature, not a bug
Accreditation rules let you connect a panel array up to 133% of the inverter's rated AC capacity and still claim the full STC rebate, which is why a 5 kW inverter is routinely paired with up to 6.6 kW of panels. The catch people fear is clipping: around noon the array can briefly make more DC than the inverter can convert to AC, and that excess is lost. But the loss is small, typically low single-digit percent a year at sensible oversizing, because panels only reach their rated output for a couple of hours in clear midday sun. In exchange, the extra panels fill in the mornings and afternoons, flattening the generation curve. That flatter curve lifts self-consumption, the power you use yourself, which is what drives payback. A self-consumed kilowatt-hour offsets about 30 c of grid power; an exported one earns about 5 c. Trading a tall midday spike you mostly export for a wider curve you can use is a good trade.
String, micro or hybrid: when each one wins
The type is decided by your roof and your battery plans, not by a "best" label. A string inverter (about $1,000 to $2,000) wires all panels in series into one central box. It is the right call for a simple roof facing one direction with no shade, where it is cheap and reliable, but one shaded or dirty panel drags down the whole string. Microinverters sit on each panel and convert power individually, adding roughly $150 to $200 per panel. They earn their cost on shaded, dormer-broken or multi-direction roofs, where they stop one weak panel from pulling the rest down and let you monitor each panel. A hybrid (battery-ready) inverter (about $1,500 to $3,000) handles panels and a battery in one unit, and only pays if storage is actually coming.
The lifespan mismatch and the hidden mid-life cost
Here is the number most quotes never spell out. Panels are warranted for around 25 years and usually outlive that. Inverters last roughly 10 to 15 years, so over the life of one solar system you will most likely buy the inverter twice. That mid-life replacement is the single most predictable cost in solar, and it is exactly where a bargain inverter turns expensive: a cheap unit that dies at year eight, out of warranty, costs you a full replacement plus a call-out, while a reputable brand with a 10 year warranty either lasts longer or is replaced free. Budgeting for one inverter replacement, and spending up front to delay or cover it, is not caution, it is arithmetic.
How the inverter rating caps your export and self-consumption
Whatever your panels produce, the inverter is the gate it must pass through, and that gate is sized in AC kilowatts. A 5 kW inverter cannot deliver more than 5 kW to your home or the grid at any instant, regardless of how much DC the array makes. This is why sizing is a balance rather than a maximum: you want the inverter small enough to be cheaper and to push the panels into useful oversizing, but large enough that clipping stays minor. It also interacts with export limits, because in some networks the inverter AC rating is what your distributor caps for grid export. Getting the rating right is therefore not just about today's generation, it sets the ceiling on both what you can self-consume at peak and what you are allowed to send back.
What this costs real households
How good systems end up underperforming
The mechanism above is not theory. It is exactly how well-meaning buyers leave money on the table.
They pay for a "matched" inverter they barely use
A household accepts a quote that proudly matches a 6.6 kW inverter to 6.6 kW of panels. They paid for inverter headroom that only does anything for the hour around noon. A 5 kW inverter would have been cheaper, claimed the same rebate, and the oversized array would have lifted the power they actually use the rest of the day.
They buy the cheapest inverter and replace it twice
A buyer shaves a few hundred dollars by taking a bargain inverter with a short warranty. It fails at year eight, out of cover, and the replacement plus call-out wipes out the saving and then some. Over 25 years they pay for three inverters where a reputable brand would have needed one or two.
They put a string inverter on a shaded, complex roof
The roof has a chimney, a dormer and panels on two pitches. A single string inverter ties them all together, so the shaded panel each afternoon drags the whole string down. Microinverters would have isolated the problem and recovered generation they now lose every day.
They skip the hybrid, then add a battery the hard way
A household says no to a battery to keep the quote down, takes a plain string inverter, then decides two years later they do want storage. Now they need a second inverter or a full swap, when a hybrid up front would have made the battery a simple add-on.
The insider insight
The hybrid inverter is a bet, and most people make it wrong
Here is the part the brochures never frame honestly. A hybrid (battery-ready) inverter is sold as future-proofing, and it sounds responsible to buy one "just in case". But a hybrid is not insurance, it is a bet on a specific decision: that you will add a battery within roughly five years. If you will, the hybrid saves you buying and installing a second inverter later, and that saving is real. If you will not, you have spent $1,500 to $3,000 of capacity that does nothing your panels needed, money that would have lifted self-consumption faster sitting in a hot-water timer or an extra string of panels.
The non-obvious truth: the right inverter decision is the opposite of the cautious one. Do not hedge. If a battery is genuinely on your plan within about five years, commit and buy the hybrid now, because retrofitting storage onto a plain string inverter is the expensive path. If a battery is a vague "maybe one day", buy the cheaper string inverter, put the difference into things that lift self-consumption today, and add a hybrid or AC-coupled battery if and when you actually commit. The wasteful middle, a hybrid bought "to be safe" for a battery that never comes, is the most common and most expensive mistake.
The practical consequence: decide the battery question before you decide the inverter, not after. The inverter type is downstream of that one call, and getting the order right saves you a four-figure mistake either way.
Grounded in the analysis
What you should actually do
Specific moves that follow from how inverters work, not generic advice.
Oversize the panels on purpose
Aim for an array up to about 133% of the inverter rating, the legal max for the full rebate. A 5 kW inverter on 6.6 kW of panels beats a matched 6.6 kW inverter: it is cheaper, claims the same rebate, and the flatter curve lifts the power you actually use. Use the sizer above to land the ratio.
Match the type to your roof
Simple, unshaded, one-direction roof: a string inverter is plenty. Shaded, complex or multi-pitch roof: pay the per-panel premium for microinverters. Battery within about five years: buy a hybrid now. Decide the battery question first, because it sets the type.
Budget for one replacement, buy a brand
Plan for the inverter to be replaced once over the system's 25 year life, because it is the part most likely to fail. Spend up front on a reputable brand with a 10 year warranty rather than the cheapest unit, because a bargain inverter you replace twice costs more in the end.
See why the panel is the cheap part, work out whether a battery pays before you pick a hybrid, or check the STC rebate that funds it all.
Current figures, last updated 2026-06-15
Australian inverter figures for 2026. Sources: the Clean Energy Regulator (STC scheme and the 133% array rule), the Clean Energy Council (accreditation and product listing), AS/NZS installation standards, and the Australian Energy Regulator (DMO 2025-26) for usage and export values. Costs are typical retail ranges and vary by brand, size and installer. Confirm current figures before purchase.
The bottom line
Why this matters right now
Panels keep getting cheaper and more interchangeable, which pushes every real decision onto the inverter. It is the part that sets your usable ceiling, the part that decides whether a battery is a simple add-on or an expensive retrofit, and the part you will most likely replace once over the system's life. Get it right and the panels become an afterthought, which is exactly what they have become. Oversize the panels against a smaller inverter on purpose, match the type to your roof and your battery plans, decide the battery question before you pick the inverter, and budget for one mid-life replacement with a reputable brand. Do that and you have made the choice that actually moves your result, instead of agonising over a panel badge that barely does.
Common questions
A Selectra expert answers your solar inverter questions
Accreditation rules let your panel array be up to 133% of the inverter's rated AC capacity while you still claim the full STC rebate. That is why a 5 kW inverter is routinely paired with up to 6.6 kW of panels. It is deliberate, not a defect: panels only hit their rated output for a couple of hours around noon, so the extra panels fill in the morning and afternoon, flatten the generation curve and lift the power you can actually use. You lose only a sliver to clipping at midday.
Roughly 10 to 15 years, against about 25 years for the panels. That mismatch matters: the inverter is usually the first component to fail and the single most likely replacement cost over the life of the system. When you budget for solar, plan for one inverter replacement, not zero. A reputable brand with a 10 year warranty is cheaper over 25 years than a bargain unit you replace twice.
It depends on your roof, not on which is "best". A single string inverter (about $1,000 to $2,000) is the right call for a simple, unshaded roof facing one direction. Microinverters, which add roughly $150 to $200 per panel, sit on each panel and convert power individually, so shade or a different roof pitch on one panel no longer drags down the rest. Pick microinverters for shaded or complex multi-direction roofs, and a string inverter for a simple roof where the extra cost buys you little.
A hybrid (battery-ready) inverter handles both your panels and a battery in one unit, and costs about $1,500 to $3,000. It only pays if you will actually add storage. If a battery is on your plan within about five years, a hybrid now saves you buying a second inverter later. If a battery is not in your plans, the extra spend is wasted: a plain string inverter does the same job for your panels for less.
On its own, a string inverter runs about $1,000 to $2,000, microinverters add roughly $150 to $200 per panel, and a hybrid (battery-ready) inverter is about $1,500 to $3,000. Inside a full system the inverter is bundled into the installed price, with a common 6.6 kW system landing around $5,000 to $6,500 after the STC rebate. Buying the cheapest inverter is a false economy, because it is the part you are most likely to replace.
Barely. When the array briefly produces more DC than the inverter's AC rating around midday, the excess is "clipped" and lost, but at sensible oversizing (up to 133%) that loss is small, typically low single-digit percent a year. It is easily outweighed by the extra morning and afternoon generation, and that wider curve lifts self-consumption, which is what actually drives payback. A self-consumed kilowatt-hour is worth about 30 c against roughly 5 c exported, so a flatter, more usable curve beats a taller midday spike you mostly export for cents.
