How do you know if your solar is working? Four checks, sixty seconds, no ladder required.
Solar has no moving parts and lives on a roof you never look at, so when it fails it fails quietly. Plenty of Australian households run for months — sometimes years — on a system that stopped generating, and blame the rising bill on prices. Here's the fastest honest check, what normal output actually looks like (winter is not a fault), the failures that never trigger a warning light, and exactly who to call — in the order that doesn't waste weeks.
Reviewed by the Mission Green Energy Team · Updated August 2026
How do you know
if your solar is working?
Four things, in this order. Most people can answer all four from the driveway and their phone.
Solar is quiet, it has no moving parts, and it lives on a roof you never look at. So systems fail silently, and Australian households routinely run for months — occasionally years — on a system that stopped generating and never said so. The bill creeps up, and it gets blamed on prices.
Here is the fastest honest check, in order:
- Look at the inverter. On a sunny day, mid-morning to mid-afternoon, it should show a green light or a normal status and a generation figure above zero. A red or flashing light, a blank screen, or a fault code means stop here — go to inverter red lights and fault codes.
- Check today's generation against a comparable day. Open your monitoring app and compare a clear sunny day now with a clear sunny day from the same season a year or two ago. Same weather, same season, roughly the same number.
- Check your bill's import figure, not just the total. If daytime import has climbed while your habits haven't, the system may be generating less than you assume.
- Check the meter or your retailer's data for exports. If you normally export and exports have gone to zero, something changed — and it may be an export limit rather than a fault. See export limits explained.
If all four look right, your solar is working. If any looks wrong, the rest of this page narrows it down.
What “normal” output
actually looks like.
The most common false alarm is a healthy system being measured against the wrong expectation.
Before diagnosing a fault, make sure you're comparing fairly. A 6.6 kW system does not produce 6.6 kW most of the day, and it never produces its rated output for a full day.
- Peak output is a moment, not a day. Panels are rated under standard test conditions that your roof rarely matches. Seeing 4.8 kW from a 6.6 kW array at noon is normal, not a fault.
- Heat reduces output. Panels lose efficiency as they get hot, so a 38°C February afternoon can produce less instantaneous output than a mild sunny 24°C day. People often read this backwards.
- Winter is genuinely much lower. Shorter days and a lower sun angle mean winter generation is a fraction of summer. Comparing June to December and concluding the system is broken is the single most common false alarm.
- Compare like with like: same season, similar weather, previous year. That's the only comparison that means anything.
- Shading changes over years. The tree that was fine in 2019 may now clip your morning production. That's a real loss but not a fault — and it's fixable with secateurs rather than a technician.
A useful rule of thumb: a sustained drop of more than roughly 15–20% against the same period last year, on comparable weather, is worth investigating. Day-to-day variation of far more than that is completely normal.
The failures that
never announce themselves.
Six things that can be wrong while everything looks fine from the ground.
One string down
Many systems run two strings of panels. If one drops out — a failed isolator, a rodent-chewed cable, a connector that has corroded — the inverter keeps running happily on the other. You lose roughly half your generation with no fault light at all. Only the numbers reveal it.
Monitoring stopped, not solar
The opposite trap: the app has gone dark because the wifi password changed or the dongle failed, while the system generates perfectly. Before panicking about the array, check whether the inverter screen itself shows normal output. Fixing monitoring is cheap; assuming the worst is not.
Tripped DC or AC isolator
A rooftop or wall isolator that has tripped or been switched off — sometimes by a tradesperson working on the roof, sometimes by weather ingress — stops generation completely. Worth a look before anything else, though never open or interfere with DC isolators yourself.
Three more worth knowing. Grid voltage rise can cause the inverter to throttle back or drop out repeatedly around midday — it looks like an intermittent fault and is actually the network's voltage being too high; your distributor can measure it. An export limit imposed at connection can make it appear you've stopped exporting when generation is fine. And soiling — heavy bird droppings, thick dust, bushfire ash — can shade cells, though on a tilted roof rain does most of the cleaning; our guide on whether panel cleaning is worth it covers when it genuinely matters.
Notice how many of these produce no alarm. That's why an occasional deliberate check beats waiting to be told.
Who do you actually
call when it's not working?
In order — and the order matters, because the wrong first call wastes weeks.
- Your original installer, first. They hold the workmanship warranty, they know your system, and under Australian Consumer Law your claim sits with the business that sold you the goods. Start here even if you're annoyed with them.
- If they've closed down — and hundreds of Australian solar companies have — your rights don't die with them. Manufacturer warranties on the panels and inverter are still live, and consumer guarantees still apply to whoever sold you the goods. We've written the claim ladder out in full: claiming when your installer has gone bust and orphaned solar systems.
- Any CEC-accredited installer for a paid service call if you're out of warranty or just want it fixed now. Ask for a written report of what they found — you may need it for a warranty claim later.
- Your electricity distributor (not your retailer) if the problem looks like grid voltage, an export limit, or the meter. They own the poles, wires and your connection, and they can measure voltage at your point of supply.
- Your retailer only for billing, tariff and feed-in credit questions — they don't touch hardware.
- Your state's energy ombudsman or fair trading body if you've been fobbed off. Free, independent, and taken seriously. Who can actually help with a solar complaint maps out which body handles what.
How to never be
six months behind again.
Three habits, none of which takes more than a minute.
Turn on the alerts. Most monitoring platforms can email or push a notification when the system stops reporting or generation drops abnormally. Almost nobody enables this at handover. It is the single highest-value minute you will spend on your solar system.
Screenshot a good day, once a year. A clear sunny day in the same month each year gives you a genuine baseline. Memory is unreliable; a screenshot from two Februaries ago is not.
Read the import figure on one bill a year, not the total. Total bills move with prices and are a poor signal. Daytime import climbing while your habits stay the same is the earliest honest warning that generation has dropped.
And if you're thinking about a battery or an inverter replacement, this is exactly the data that makes those decisions properly — when a solar inverter needs replacing covers what a genuine decline looks like versus normal ageing.
How do I know if my solar is working?:
your questions, answered.
Four checks, in order, and most can be done in about a minute. First, look at the inverter on a sunny day between mid-morning and mid-afternoon: it should show a green light or normal status and a generation figure above zero, and a red or flashing light, blank screen or fault code means stop and investigate that. Second, open your monitoring app and compare today's output against a clear sunny day in the same season from a previous year — comparing summer to winter is the single most common false alarm. Third, check the import figure on your bill rather than the total, since daytime import climbing while your habits are unchanged suggests generation has fallen. Fourth, check whether you are still exporting; if exports have dropped to zero that may be a fault, or it may be a network export limit rather than a problem with your system. If all four look normal, your solar is working.
Less than its rated size, and far less than people expect. A 6.6 kW system does not produce 6.6 kW through the day — that rating is measured under standard test conditions your roof rarely matches, so seeing 4.8 kW at noon from a 6.6 kW array is normal rather than faulty. Output also falls as panels get hot, so a 38 degree February afternoon can produce lower instantaneous output than a mild sunny 24 degree day, which people frequently read backwards. Winter generation is a fraction of summer because of shorter days and a lower sun angle. The only comparison that means anything is like for like: the same season, similar weather, against your own system in a previous year. As a rule of thumb, a sustained drop of more than roughly 15 to 20% against the same period last year on comparable weather is worth investigating, while day-to-day swings well beyond that are entirely normal.
Yes, and this is why occasional deliberate checks matter. Several failures are completely silent. Many systems run two strings of panels, and if one drops out through a failed isolator, a rodent-damaged cable or a corroded connector, the inverter continues running normally on the other string — you lose roughly half your generation with no fault indication at all, and only the numbers reveal it. Grid voltage rise can make the inverter throttle back or disconnect intermittently around midday, which looks like a random fault but is actually the network's voltage being too high. An export limit applied at connection can make it appear you have stopped exporting when generation is fine. Soiling from heavy bird droppings, thick dust or bushfire ash can shade cells without triggering anything. And the reverse trap exists too: monitoring can fail while the system generates perfectly, usually because a wifi password changed or a dongle died.
Your original installer first. They hold the workmanship warranty, they know your system, and under Australian Consumer Law your claim sits with the business that sold you the goods — so start there even if the relationship has soured. If that company has closed down, and hundreds of Australian solar companies have, your rights do not disappear with it: manufacturer warranties on the panels and inverter remain live and consumer guarantees still apply. Any Clean Energy Council accredited installer can perform a paid service call if you are out of warranty or simply want it fixed quickly, and it is worth asking for a written report of what they found in case you need it for a claim later. Contact your electricity distributor rather than your retailer if the issue looks like grid voltage, an export limit or the meter, since the distributor owns the connection. Use your retailer only for billing and feed-in questions, and escalate to your state energy ombudsman if you are being ignored.
No. Two independent reasons, either of which is sufficient. Solar DC wiring is live whenever there is daylight — there is no off switch on a panel, and the DC side can carry hundreds of volts, which is why DC isolators should never be opened or interfered with by anyone other than a qualified person. Separately, falls from height are among the leading causes of serious injury and death in Australia, and a residential roof combines edges, fragile surfaces and often a poor working position. A few hundred dollars of annual generation is never worth either risk. Everything genuinely useful can be checked from the ground: the inverter display and status light, your monitoring app, the import and export figures on your bill, and a visual look at the array from the yard with binoculars if you want to check for obvious soiling or damage. If something needs inspecting up close, pay an accredited installer who has height-safety equipment.
Three habits, none taking more than a minute. Enable alerts in your monitoring platform — most can email or push a notification when the system stops reporting or when generation drops abnormally, and almost nobody switches this on at handover, which makes it the highest-value minute you will spend on your system. Take a screenshot of a clear sunny day once a year in the same month, giving you a genuine baseline, because memory is unreliable and a screenshot from two years ago is not. And read the import figure on one bill a year rather than the total, since totals move with electricity prices and are a poor signal, whereas daytime import climbing while your habits are unchanged is the earliest honest warning that generation has fallen. Together these turn a problem you might notice in six months into one you notice in a week.
Where these figures come from.
Figures on this page are drawn from primary sources and were current as at August 2026. Programs, prices and standards change — confirm at the source before relying on a number.