PV maintenance and common faults
Maintaining a PV installation is mostly mechanical: cleaning the modules when soiling cuts output, and checking the mounting system for loose clamps, corrosion and secure fixings, while the electrical inspection is left to a qualified electrician. A well-built array in the right metals needs little attention, but the few checks that matter protect both the yield and the twenty-five-year-plus life of the structure. This guide covers cleaning, the mounting checks, the common mechanical faults, and where the electrical side takes over. For the parts being checked see our guide to PV roof mounting components.
What PV maintenance actually involves
Solar maintenance splits into two halves. The mechanical half, cleaning the glass and checking the mounting, is straightforward and is where most of the routine work sits. The electrical half, testing the modules, wiring, inverter and earthing, is specialist work for a qualified electrician. A properly built mounting system in aluminium and galvanised steel is designed to be low-maintenance, so the mechanical routine is a periodic clean and a visual check rather than constant attention. Knowing which half a task belongs to keeps the work safe and the responsibilities clear.
Cleaning the panels
Dirt, dust, pollen, bird droppings and leaves all cut the output of a module by shading the cells, so cleaning restores lost yield. The safe method follows the module maker’s guidance: use plenty of clean, low-mineral water and a soft brush or squeegee, never an abrasive pad or a harsh chemical that could scratch the glass or the anti-reflective coating. Cleaning is best done early or late in the day when the glass is cool, because pouring cold water onto hot glass in full sun risks thermal shock. On tilted and vertical arrays rain does much of the work, so cleaning is only needed where soiling is heavy.
How often to clean
How often an array needs cleaning depends on where it stands. A site near a busy road, a farm, a quarry or the coast picks up dust, salt or organic soiling faster than a clean suburban roof. Tilted and vertical modules shed rain and self-clean to a degree, so many arrays need only an annual or twice-yearly clean, while a flat or low-tilt array holds dirt and water longer and may need more. The right interval is the one that keeps the yield up without over-cleaning, judged from the site and the output rather than a fixed calendar.
Checking the mounting system
The mounting deserves a periodic visual check because it carries the array through every storm. The things to look for are simple: clamps still tight to the correct torque, rails and roof anchors secure, no movement at the fixings, and no water pooling where it should drain. On a rooftop system the roof hooks and the sealed penetrations are checked for tightness and for any sign of a leak. Catching a loose clamp or a working fixing early, before wind can worsen it, is what keeps a small maintenance job from becoming a failure.
Checking for corrosion
Corrosion is the slow fault that a check is meant to catch. Aluminium rails and stainless fixings should show none, which is why they are used, but a bare cut edge on a galvanised part, or a spot where a dissimilar metal has been introduced, can start to corrode over years. The visual check looks for white or red staining at joints and cut ends, and any bare galvanised cut is re-protected with zinc-rich paint. Because the structure is built in corrosion-resistant metals from the start, this is usually a quick confirmation rather than a repair. For the aluminium behaviour see our guide to whether aluminium corrodes.
Common mechanical faults
A handful of mechanical faults account for most mounting problems. A clamp that was under-tightened at installation can loosen and let a module shift, and one that was over-tightened can distort the frame. A roof penetration sealed poorly can let water in. Thermal expansion, if the rails were not allowed to move, can stress the joints over many hot and cold cycles. And a bare cut edge left unprotected can corrode. All five trace back to installation detail, and all are avoided by fitting the system correctly and checking it periodically rather than leaving it untouched for years.
Faults that belong to the electrician
Some faults are electrical and are diagnosed and fixed only by a qualified electrician, not through the mounting. A drop in output can come from a failing inverter, a faulty string, a hot spot on a shaded or damaged cell, potential-induced degradation, or a wiring or earthing fault. These are found with electrical testing and monitoring, and they sit outside the scope of a mounting supplier. If a mechanical check finds the structure sound but the output is still low, the next step is an electrical inspection. ULAMEX supplies and stands behind the mounting, not the electrical system.
A simple maintenance routine
A rooftop or ground array does not need frequent attention, but a light routine keeps it at its best. A visual check once or twice a year covers the clamps, rails and anchors for tightness and the metals for any corrosion, and a clean is done when soiling has visibly built up rather than to a fixed date. After a severe storm or a heavy snow, an extra look confirms nothing has shifted or been damaged. Keeping a simple record of what was checked and when makes each visit quicker and shows the array has been looked after, which matters for any warranty on the modules or the structure. The routine is short precisely because the system was built to last.
Winter, snow and storms
The seasons that test an array are worth a note. Snow that settles on a tilted array usually slides off as it warms, and a vertical solar fence sheds it entirely, but a heavy fall on a low-tilt roof array adds a real load that the structure was sized for to the Eurocode. Clearing snow by hand is rarely needed and risks scratching the glass, so it is done only where a manufacturer advises it and with a soft tool. After a storm, the check looks for lifted or loosened clamps, displaced ballast on a flat roof, and any damage at the roof penetrations. A structure built and founded correctly comes through the winter, which is the point of sizing it properly.
Spare parts and replacements
Over a long life an array may need a mounting part replaced, a clamp, a roof hook, a section of rail or a set of fasteners, after damage or an alteration. Because the components are standard aluminium and stainless parts to known profiles, they can be matched and supplied rather than the whole system being disturbed. Using the correct matching part, in the same metals, keeps the corrosion protection intact and avoids introducing a dissimilar metal into a wet joint. ULAMEX can supply replacement mounting components against the original system detail, so a repair restores the array rather than compromising it.
Keeping the site clear
Around a ground array, the site itself needs maintaining. Vegetation is kept cut back so it does not shade the lowest modules or hold moisture against the structure, and the drainage is kept clear so water runs away from the foundations rather than pooling at the posts. This light groundwork protects both the output and the structure, and it keeps safe access for the cleaning and the checks above. On a perimeter-fenced site the fence and gates are walked as part of the same round, so a loose panel, a worn latch or a gap at ground level is caught early, before it becomes a way in. A tidy, well-kept site is a long-lived one, and the effort is small against the value it protects.
Documentation and warranty
A little paperwork protects the array as much as the checks do. Keeping the specification of the mounting system, the module details and a simple log of cleaning and inspections means any later question, a warranty claim, a repair, an insurance query, can be answered from a record rather than a guess. Where the mounting components were supplied under EN 1090, the material and manufacturing documentation supports that. A logged history also shows the array has been maintained, which many module and workmanship warranties require. This record-keeping costs almost nothing and turns a maintenance routine into evidence that the installation has been cared for across its life, which is exactly what an insurer or a warranty assessor will ask to see.
Mounting support from ULAMEX
ULAMEX manufactures PV mounting components under EN 1090 and has supplied the trade since 1988.
| Maintenance area | What to check |
|---|---|
| Cleaning | Clean low-mineral water, soft brush, cool glass; follow the module maker’s guidance |
| Clamps and rails | Correct clamp torque, secure rails and anchors, no movement at fixings |
| Corrosion | No staining at joints or cut ends; re-protect any bare galvanised cut |
| Roof detail | Roof hooks tight, sealed penetrations sound, drainage clear |
| Electrical (electrician) | Inverter, strings, hot spots, PID, wiring and earthing, not the mounting |
Need mounting parts or replacements? Send the system detail and ULAMEX will return a non-binding quotation with lead time and availability. Read the full PV mounting systems guide, browse the photovoltaic mounting range, or view our supply capabilities. Contact the export desk at [email protected] or +48 504 424 761.
Frequently asked questions
How do you clean solar panels safely?
Follow the module maker’s guidance: use plenty of clean, low-mineral water and a soft brush or squeegee, never an abrasive pad or a harsh chemical that could scratch the glass or coating. Clean early or late when the glass is cool, because cold water on hot glass in full sun risks thermal shock. Tilted and vertical arrays self-clean in rain.
How often should panels be cleaned?
It depends on the site. A location near a road, farm, quarry or coast soils faster than a clean suburban roof. Tilted and vertical modules shed rain and self-clean, so many arrays need only an annual or twice-yearly clean, while a flat or low-tilt array holds dirt longer. Judge the interval from the site and the output, not a fixed calendar.
What should I check on the mounting system?
Clamps still tight to the correct torque, rails and roof anchors secure, no movement at the fixings, and no water pooling where it should drain. On a rooftop system the roof hooks and sealed penetrations are checked for tightness and leaks. Catching a loose clamp early, before wind can worsen it, prevents a bigger failure.
What are the common mechanical faults?
An under-tightened clamp that lets a module shift, an over-tightened one that distorts the frame, a poorly sealed roof penetration that leaks, thermal stress where rails were not free to move, and a bare cut edge that corrodes. All trace back to installation detail and are avoided by fitting the system correctly and checking it periodically.
Why has my array’s output dropped?
First check the mechanical side: soiling on the glass or a shading obstruction. If the structure is sound and the glass clean but output is still low, the cause is likely electrical, a failing inverter, a faulty string, a hot spot, potential-induced degradation or a wiring fault, which a qualified electrician diagnoses with testing. That is outside the mounting scope.
Does ULAMEX service the electrical system?
No. ULAMEX supplies and stands behind the mounting: the aluminium rails and clamps, the roof anchors and the galvanised structure, all under EN 1090, and can supply replacement mounting parts. The inverter, wiring, earthing and electrical testing are the work of a qualified electrician. Send the system detail for mounting parts or a quotation.