Generation figures lower than last year. Something visible on the glass you can't identify from the ground. Panels that went up three years ago and haven't been touched since.
Any of those is a reason to get eyes on the system. The monitoring app records what the panels produced. It has no way of showing you what is happening to the components sitting on your roof.
A solar panel inspection, properly done, produces a written condition report covering every part of the system. This is what that process involves, what it finds on Auckland installations, and what the report should contain.
Your inverter records what the system produced. It has no reference point for what the system should have produced given the conditions on any particular day.
Output loss from soiling, biological growth, or developing hardware faults happens gradually. It sits inside normal daily and seasonal variation. Nothing flags it. The app keeps showing numbers, and those numbers keep looking roughly normal, even as the gap between actual and potential output grows quietly in the background.
This is the core problem a condition report addresses. The assessment establishes what is actually on the roof, what condition the components are in, and whether anything found is costing generation or heading toward a more serious problem. That information does not exist in the monitoring data. It only exists on the roof.
A thorough assessment works through the system component by component. Here is what each part involves and what it is looking for.
The technician checks the glass on every panel for physical damage: cracks, discolouration, and any sign of delamination. Delamination is what happens when the internal layers of the panel begin to separate. In NZ's climate, biological growth is a contributing factor. Lichen uses root-like structures to penetrate the seal between the glass and the frame, putting physical pressure on the bond and creating a pathway for moisture. Once moisture works into the panel layers, the separation progresses. By the time delamination is visible from the ground, the panel is often permanently damaged.
Early-stage delamination shows as cloudy or yellowed areas on the surface. It may start as something that looks cosmetic. It does not stay that way.
The biological assessment runs alongside the glass check. The technician records what type of growth is present, where it is, and at what stage it has established. Light discolouration at the frame margins is a different situation from lichen covering cell area across multiple panels. That distinction determines what the service requires and whether standard cleaning is sufficient or whether a specialist remediation visit is needed separately.
For a full explanation of what lichen physically does to panel glass and why Auckland's climate makes it the primary solar maintenance concern, see lichen, moss, and biological growth on solar panels.
Aluminium frames carry reasonable corrosion resistance. The steel fasteners and brackets used in most NZ installations do not. The inspection checks clamp torque, rail integrity, and looks for galvanic corrosion — white rust forming at the contact points between dissimilar metals.
Loose clamps are worth finding early. A panel that is not held firmly will flex in wind, and that flexing creates micro-cracks in the silicon cells that do not show up in the monitoring data until the damage has progressed. Caught early, a loose clamp is a straightforward maintenance observation. Left unchecked, it becomes a cell damage problem.
Coastal properties face accelerated corrosion from salt spray. Within roughly 500 metres of the ocean, mounting hardware deteriorates faster than most homeowners expect. What looks like minor surface discolouration on an inland installation may be active corrosion at the same stage on a coastal one.
The inspection checks for signs of bird activity across the full array. Droppings on the glass cause concentrated shading over individual cells, and unlike general dust, they do not respond to rainfall. They are also acidic and bond to the glass surface over time.
More significant is nesting under the panels. Birds that establish themselves beneath an array create a different category of problem. Nesting material accumulates against the cabling and mounting hardware. Droppings concentrate in one area rather than spreading across the surface. The presence of a nest often means ongoing activity that compounds between visits. The condition report records what is found and whether it warrants further action. For a full breakdown of what nesting under solar panels involves and the right sequence of steps, see birds nesting under solar panels in NZ.
DC cables run from the panels along the roof surface to the inverter. UV exposure causes the outer sheath to become brittle and crack over time. Where cables are not properly secured off the roof surface, wind movement creates chafing that works through the insulation gradually.
The monitoring app will not detect this. Unless degraded cabling causes a complete earth fault or short circuit that takes the system offline, the app keeps reporting normal generation while a serious electrical hazard develops on the roof.
The technician checks that cables are lifted off the roof surface using UV-rated fixings, that the sheath is intact and not visibly cracked or brittle, and that there is no sign of rodent damage from animals nesting under the array. Damaged cabling is documented and referred to a qualified electrician. Touching electrical components is outside the scope of a cleaning and maintenance operator.
DC isolators are the rooftop safety switches that allow the system to be powered down. Junction boxes are the weatherproof enclosures where wiring connections are made.
Both are visual-only checks. The technician does not open these enclosures or touch any internal components. What they are looking at is the external condition: whether the plastic casing on the isolator is cracked or UV-degraded, whether there is visible water ingress or rust, and whether the mounting is secure.
DC isolators are the most common cause of solar-related fires. Systems installed before the 2021 update to AS/NZS 5033 often lack the metallic shroud that is now a mandatory safety requirement, and the plastic casings on those older units have had a decade of UV exposure in Auckland's conditions. Any concern identified is photographed, documented in the condition report, and referred to a qualified electrician or the original installer.
Mounting hardware passes through the roof surface at multiple points. Each penetration is weatherproofed with silicone or a rubber boot. UV exposure degrades these seals over time. Once a seal fails, the penetration becomes a water ingress path.
Because the solar array covers the penetration points, standard roof checks often miss deteriorating seals until water has already worked its way into the structure. The inspection checks the visible portion of each seal for cracking, perishing, or separation from the mounting hardware, and records anything that warrants further attention.
A condition report is not complete without before and after inverter readings. The reading taken before any cleaning begins records what the system was producing. The reading taken after records what it produces once the panels are clean.
The difference between those two numbers is the objective measure of what the contamination was costing in real generation. If output recovers meaningfully after the visit, the loss was real and has now been recovered. If it changes very little, the system was already running close to its potential and the inspection findings stand on their own.
NZ's solar install base was built across many years by many different operators using a wide range of hardware brands and component types. There is no standardisation. A system installed in 2014 may have completely different isolator hardware, cable management, and frame fixings from a system installed in 2018 by a different operator on the same street.
This matters for condition assessments because general guidance only goes so far. What a technician finds on one roof is not reliably predictable from what they found on the last one. A physical, eyes-on assessment of the actual components present is the only way to know what condition a specific system is in.
That variety problem will only grow. NZ is heading into a period of significant solar installation growth. More systems, more operators, more hardware types, and more variation in install quality. In ten years, the Auckland install base will be far more diverse than it is today, and the gap between systems that have been regularly assessed and those that have not will be correspondingly wider.
Every MiHT solar visit includes both a professional clean and a condition report. The report is part of the service, not an add-on.
MiHT Home Energy System Care treats every solar panel care visit as a full system assessment. The condition report produced at the end covers: before and after photos of the panel array and any findings of note; a record of the contamination type and severity across the panels; the biological growth assessment, including whether early-stage treatment was applied during the visit or whether a specialist remediation visit is recommended; a visual check of frames, mounting hardware, cabling, isolator casings, and junction boxes, with any concerns documented and referred; before and after inverter output readings; and a clear summary of what was done, what was found, and what needs follow-up.
That record matters beyond the current visit. Manufacturers require evidence of regular professional maintenance to keep performance warranties valid. Home insurance policies typically require the property to be maintained in reasonable condition. A written condition report with photos is the documentation that proves the system was professionally assessed, and it gives the next technician a baseline to compare against rather than starting from scratch.
The overseas solar content that dominates search results is written almost entirely for arid climates where dust is the primary concern. Rainfall manages biological growth in those environments. The advice, the cleaning frequencies, and the risk framing all reflect that reality.
Auckland is different. The humidity, the coastal exposure affecting a significant proportion of properties, and the UV intensity that degrades plastics faster than many homeowners expect combine to create a maintenance environment that most global solar content does not address. Systems installed here 8 to 10 years ago are now at the age where inverters approach end of useful life, isolator casings have had a decade of NZ UV exposure, and panels that were never professionally assessed may have biological growth that has been establishing since the first year after installation.
A condition report is how you find out where your specific system actually sits.
Any system not assessed since installation should be treated as a priority, regardless of how the monitoring app looks or how long ago the panels went up. For a full picture of what typically builds up on a never-serviced system and what that first visit finds, see solar panels that have never been professionally serviced.
Beyond that, every one to two years is a reasonable interval for most Auckland installations. Flat or low-pitch roofs, coastal properties, properties with significant bird activity, and west-facing arrays where biological growth accumulates faster all warrant more frequent attention.
A visual check from the ground using phone camera zoom is a useful habit between professional visits. A grey cast across the surface, white streaking from bird droppings, greenish patches at the frame margins, or any sign of nesting activity under the panels are all reasons to book earlier than the next scheduled visit.
For guidance on building the right maintenance schedule for your specific installation, see solar panel maintenance in NZ: how to build the right plan.
If you want to understand where your solar system currently stands before booking anything, the MiHT Home Energy Health Assessment takes a few minutes and gives you a clear picture across solar, heat pumps, and ventilation before you decide what to do next.
A professional solar panel inspection is a condition assessment of the full system. It covers the panel glass for physical damage, delamination, and biological growth; frames and mounting hardware for corrosion and loose fixings; DC cabling for UV degradation and secure attachment; DC isolator casings and junction boxes for visible signs of water ingress or damage; roof penetration seals; and any sign of bird activity or nesting under the array. The visit includes a professional clean, before and after inverter readings, and ends with a written condition report covering everything found. Any issue outside the scope of cleaning and maintenance is documented and referred to a qualified electrician or the original installer.
A solar panel condition report is the written record produced at the end of a professional assessment visit. It includes before and after photos, a record of contamination type and severity, the biological growth assessment, visual findings on hardware and cabling, before and after inverter readings, and a clear list of any issues requiring referral. It is your maintenance record for the system and the documentation needed to support manufacturer warranty claims and home insurance requirements. At MiHT, the condition report is included as part of every solar service visit, not charged separately.
Every one to two years is a reasonable starting point for most Auckland installations. That interval shortens for flat or low-pitch roofs, coastal properties within around 500 metres of the ocean, properties with significant bird activity, and west-facing arrays where biological growth accumulates faster. Any system not assessed since installation should be treated as a priority regardless of how long ago the panels were installed or what the monitoring app is showing.
Yes, and this is where the inspection has its greatest value. Monitoring apps record what the system produced. They do not detect UV-degraded cabling, failing roof penetration seals, corroding mounting hardware, delaminating panels, DC isolator casings taking on water, or bird nests establishing under the array. These faults develop slowly and do not appear in the monitoring data until they cause a significant disruption. A physical condition assessment is the only way to find them before that point.
Any finding outside the scope of cleaning and maintenance, including damaged cabling, DC isolator concerns, roof seal failures, or inverter anomalies, is documented clearly in the condition report and referred to a qualified electrician or your original installer. A cleaning and maintenance operator is not a registered electrician and cannot legally open electrical enclosures or touch internal wiring. The correct outcome for any electrical finding is a written referral in the condition report, not an on-the-spot fix.
Manufacturers typically require evidence of regular professional maintenance to keep performance warranties valid. A written condition report with photos from a professional visit is the documentation that supports a warranty claim if one becomes necessary. Systems with no maintenance history are in a significantly weaker position when a warranty issue arises.