How do you maintain solar panels?
Solar panels need little hands-on care. What they do need is someone watching the output, a few safe checks from the ground, and a professional for anything on the roof or inside the electrics.
Solar panels have no moving parts, so maintenance is mostly watching your output, spotting visible problems and getting the right person in when something changes. There's no legal requirement for a yearly wash or service, but your handover pack should include a recommended maintenance schedule: MCS's advisory schedule for a privately owned home is a visual check by you every year and an inspection by an MCS installer at around 10 and 15 years, and some panel manuals recommend more (Trina and JinkoSolar suggest a preventive inspection every six months). The real risk is a silent loss: an inverter alert nobody reads, one string producing less than it should, pigeons nesting under the array, or a monitoring login that stopped working months ago. Keep your system's paperwork together, check your monitoring app now and then, and leave anything on the roof or inside the electrics to a professional.
This guide covers the whole system, from handover to the years that follow. Whether the glass needs washing is a separate question, covered in our guide to cleaning solar panels. The distinction matters when you compare contracts: a clean isn't an electrical check, and an inspection doesn't automatically include a clean.
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What wears, and what doesn't
The parts of a system that need attention:
- The inverter. It's power electronics working every day. Free airflow, a dust-free spot, its operating temperature and its error codes are the first things to watch. It has its own warranty and life span, separate from the panels'.
- Connectors and cables. Joints and runs exposed to sun and rain are where faults start and, at worst, where hot spots form.
- The panels. You don't service them; you watch them. Look for persistent dirt, new shade from a growing tree (see how shading affects output), broken glass or a loose frame.
- The mounting and roof. Rails, hooks, flashing and the roof covering around them: this is about keeping your roof watertight as well as keeping the output up.
- Isolators and protection devices. They're part of your electrical installation. Checks here are for a qualified electrician, not the homeowner.
If you have a battery, treat it as its own component with its own temperature limits and warranty conditions from the manufacturer.
The UK extras: pigeons and storms. Pigeons like the sheltered gap under roof panels. Nests and droppings build up, block drainage and foul the glass. Bird mesh around the edge of the array stops them getting in, and it's cheapest to fit while scaffolding is already up. In England, Wales and Scotland it's an offence to damage or destroy a wild bird's nest while it's in use or being built, so any bird-proofing should start with a check for active nests. After a storm, check your output and look for visible damage from the ground rather than going up to look.
Start with a proper handover file
When your installation is finished, ask for and keep:
- the MCS certificate, which you need to sign up for a Smart Export Guarantee tariff in Great Britain;
- the exact models and serial numbers of the panels, inverter and any battery, with their manuals, datasheets and warranty documents;
- the system layout (which panels are on which roof face and string) and the performance estimate from your quote;
- the electrical installation certificate, confirmation that the installer notified your network operator (DNO), and any building regulations paperwork;
- the maintenance schedule: the checks you should do yourself, how often, and the recommended date for the first professional inspection (MCS installers must include this);
- the installer's workmanship warranty, and details of any insurance-backed guarantee;
- the installer's, supplier's and manufacturers' contact details.
Note the commissioning date. Manufacturer warranties can start on different dates and some need registering, so check each document.
Make sure you own the monitoring account, not just the installer. Test that alerts reach you and that you can view and export the history. A login held by a company that's since closed makes diagnosis and switching installer much harder. Our guide to choosing a solar installer lists what to ask for before you sign.
Record your first year's monthly output, plus anything unusual about your roof: which way each face points, where shadows fall in winter, which panels are on which string. Comparing against your own baseline tells you far more than a national average or a sales estimate without its assumptions.
Monitoring is your preventive maintenance
Useful maintenance starts with comparing expected output with measured output. "Expected" means the MCS performance estimate your installer gave you, or a PVGIS estimate for your location, tilt and orientation. For scale, PVGIS estimates about 1,019 kWh per kWp a year in London and about 903 kWh in Edinburgh for south-facing panels at 35°. Your own figure depends on your roof and shading.
Three habits that cost nothing:
- Read monthly output, not just the yearly total. A problem shows up when you compare the same month in two different years.
- Compare strings or roof faces with each other, if your inverter or microinverters show them. Two groups facing the same way should produce almost the same.
- Don't ignore error codes. An alarm that recurs at the same time each day isn't random.
A single dull day tells you nothing. Heat and light change the instant power: a lower peak on a very hot day isn't a fault. Your bill isn't a production meter either, because what you use at home changes independently of what the panels make. If your monitoring stops updating, check the Wi-Fi connection or data logger first before concluding the panels have stopped.
Low output: what to collect before you call
A peak of 2 kW in the app doesn't on its own prove a fault in a 4 kWp system. Peak power is an instant; daily and monthly kWh are what count. Temperature, cloud, orientation, shade and the inverter's size all affect the comparison.
Before contacting your installer or the manufacturer, gather:
- the panel model and number, the inverter model and the commissioning date;
- daily and monthly output, a graph from a clear day and any alarm codes with the time they appeared;
- the direction of each roof face and any shade you can see from the ground, especially near chimneys and trees;
- whether shutdowns coincide with something else, such as an EV charger or a battery finishing charging;
- whether you're looking at total generation or only export: your own use explains part of any difference.
Ask the engineer to compare the design with what was installed, and to check for export limits or grid voltage issues. Don't change the inverter's grid protection settings to clear an alarm. Under the grid connection rules (G98/G99 in Great Britain), those settings can only be altered with the network operator's written agreement. If you see broken glass, exposed cable or signs of overheating, report it without touching anything or going on the roof.
Check safely from the ground
From the ground or a safe window, look for an obviously broken panel, leaves or nests building up, a new branch shading the roof, a cable that has moved or a fixing that looks wrong. Indoors, listen for unusual noise from the inverter and watch for warning lights, burning smells or damp near the equipment.
Panels in daylight can produce a dangerous voltage even when the inverter is off. Don't open isolators or the inverter, unplug connectors or try to tighten a fixing or cable. If you notice a burning smell, water damage or an exposed conductor, keep people away and call a professional.
| What you can record | What a professional should check |
|---|---|
| Output, app messages and dates | Electrical tests, connections, protection devices and causes of shutdowns |
| A photo of a panel or branch taken from the ground | Roof access, fixings and close inspection of panels |
| Visible damp, dirt or nests | Roof weathertightness, cable routes, bird mesh and repairs |
| Invoices, warranties and serial numbers | Diagnosing the fault and preparing a warranty claim |
What a service visit and contract should include
The frequency and content of a visit depend on your roof, access, the component manuals, your surroundings and any alerts. Ask for a proposal based on your system rather than a schedule presented as compulsory. A useful visit can include a visual check of panels and fixings, looking for leaks around roof penetrations, checking isolators and accessible cables, reviewing the inverter and its alert history, relevant electrical tests, and a written report.
Get these in writing before you sign:
- What's included, item by item: visual check, electrical tests, fixings, cleaning (how often), review of monitoring data, inverter firmware updates, bird mesh.
- How often, and in which season.
- Who goes on the roof, with what access, and who is responsible for any damage to the roof.
- Response times if the system stops, for a call-back and for a site visit.
- Parts: included or extra, and on what terms.
- A report after each visit, with the readings taken. Without one, you can't tell whether the work was done.
- Warranty claims: who deals with the manufacturer, and with which documents.
- Price, term, renewal and cancellation, with the price given per year so you can compare offers.
Two things not to accept: a fee with no list of tasks, and "maintenance" that consists only of looking at your monitoring portal remotely, which you can do yourself.
Is it worth paying for?
Set the cost of a contract against the value of the output at stake. Worked example (illustrative): a 4 kWp south-facing system in London produces about 4,075 kWh a year (PVGIS: 4 × 1,018.84 kWh per kWp).
| Loss assumed | Energy lost in a year | If you'd have used it at home (26.32p/kWh) | If you'd have exported it (6p/kWh) |
|---|---|---|---|
| 5% | 204 kWh | about £54 | about £12 |
| 10% | 408 kWh | about £107 | about £24 |
The loss percentages are assumptions to show scale, not UK averages. 26.32p/kWh is the Ofgem price cap unit rate for October to December 2026 (direct debit, GB average, no VAT); your standing charge doesn't change whatever the panels do. 6p/kWh is E.ON Next's Flex Export rate (variable, open to customers of any supplier, as of 23 September 2026). Most homes use some of their solar power and export the rest, so the real value sits between the two columns. Use your own tariff and export rate.
The pattern it shows: for a typical home system, good monitoring catches most of the value. A paid contract earns its keep mainly where the roof is hard to check, the system is large, or you want someone else to act on alerts.
After a fault, building work or a house sale
After a repair, ask for a written diagnosis, the reference of any replaced part and the date the system was back on. Then check that output and monitoring data return to normal. If an inverter is replaced, ask the installer to confirm the new unit is compatible with your panels and battery, is type-tested for grid connection, and that they'll handle any notification to your network operator. Our guide to microinverters vs string inverters explains which component does what.
If you're having roof work, a rewire or a battery added, agree who checks compatibility and who updates the drawings and certificates. Adding generation or storage can change your grid connection paperwork and some warranty terms. Tell your home insurer that you have solar panels and about any battery.
When you sell your home, pass on the handover file, the monitoring login, your export tariff details and the service history. It helps the next owner keep the system running and use their warranty rights.
So how often?
There's no legal interval, and MCS's own schedule is advisory: it depends on the system and the home. Start with the schedule in your handover pack (MCS installers must give you one, with a date for the first inspection) and any inspection conditions in your panel, inverter and battery warranties. Beyond that, act when something changes: monthly output drops and stays below what you'd expect, error codes recur, after a severe storm, after work on or near the roof, when pigeons move in, or when something you can see from the ground looks different. For the rest, your monitoring sets priorities better than a calendar does.
Frequently asked questions
Do solar panels need maintenance?
Very little hands-on maintenance, but they do need watching. There's no legal interval; start with the maintenance schedule in your handover pack (MCS installers must give you one, with a date for the first inspection) and any inspection conditions in your warranties. Check your monitoring regularly, keep an eye out for visible damage, dirt or nesting birds, and get a professional in for anything on the roof or inside the electrics.
How much does solar panel maintenance cost?
It depends on access and what's included, so get two or three quotes with a task list and compare like for like. Set the price against the output at stake: in our example, a 10% loss on a 4 kWp system in London is worth about £24–£107 a year, depending on whether you'd have exported it (at 6p/kWh) or used it at home (at the 26.32p/kWh October–December 2026 cap rate).
Is solar panel maintenance required for the warranty?
It depends on the manufacturer. Some warranties and manuals set conditions for installation, cleaning and inspection, and improper cleaning can void a warranty. Read the documents for your exact models and keep records of any work done.
How long does a solar inverter last?
It depends on the model, and it's separate from the panels. Inverter warranties vary widely between makes and types (string, hybrid and microinverters), so check the warranty document for your model. Replacing an inverter doesn't mean the panels need replacing: our guide on how long solar panels last covers panel warranties.
How do I know if my solar panels are working properly?
Compare your measured output month by month with your installer's MCS estimate or a PVGIS estimate for your roof, and compare strings or roof faces with each other if your monitoring shows them. A stable drop against the same month last year is the signal to act.
Should I get bird mesh fitted?
If pigeons are nesting or roosting near your roof, usually yes. Fit it while there's access, ideally at installation, and make sure no active nest is disturbed.