£100-£300 a year for a typical UK home. In a lot of years you'll spend nothing at all, then one year the inverter goes and you spend £1,200. That lumpiness is the thing most cost guides gloss over, so this one breaks the spend down job by job and tells you which ones you can skip.
Solar PV has no moving parts. That's the whole reason running costs are low. What you're really budgeting for is occasional cleaning, an electrical check every few years, and one or two inverter replacements across the system's life.
How much does solar panel maintenance cost per year?
Here's the realistic picture for a standard 10-14 panel domestic system on a two-storey house.
| Job | How often | Typical cost | Do you need it? |
| Monitoring check (yourself) | Monthly, 2 minutes | £0 | Yes |
| Professional clean | Every 1-2 years | £80-£200 per visit | Sometimes |
| Full electrical service | Every 2-4 years | £120-£200 | Recommended |
| Inverter replacement | Once or twice in 25 years | £500-£2,500 | Eventually, yes |
| Bird proofing | Once, if you get a problem | £300-£1,000 | Only if needed |
| Battery health check | Annually, if fitted | Usually inside the service | Yes, if you have one |
What does a solar panel service actually include?
About two hours of work by a qualified electrician, and roughly £120-£200 for a domestic system.
A proper MCS-style annual service covers a visual inspection of panels, frames and roof fixings, a review of your monitoring data against expected output, AC and DC electrical testing, an isolator function test, a check of cable routing and any signs of rodent damage, and a battery state-of-health check if you have storage fitted.
The output review is the part that earns its money. An engineer comparing this year's generation curve against last year's will spot a failing optimiser or a shaded string long before you'd notice it on your bill.
How much does solar panel cleaning cost?
£4-£8 per panel, or £80-£200 for a typical residential visit.
Height and pitch drive the price more than panel count does. Ground-mounted arrays and single-storey roofs can come in around £2 per panel. A steep two-storey roof needing pole-fed pure water gear or a tower pushes towards £8. Checkatrade's cost guide puts a 40-panel array above one storey at as much as £225, and 2025 quote data points to a median of about £140 for a single-storey home and £180 for a two-storey or steep pitch.
| Situation | Typical cost |
| Ground-mounted or single storey | £80-£140 |
| Standard two-storey pitched roof | £140-£200 |
| Steep pitch or awkward access | £200-£250 |
| Scaffolding needed | Add £400+ |
Do UK solar panels actually need cleaning?
Usually less often than you'd think. British rain does most of the work on a pitched roof at 30-45 degrees.
Cleaning genuinely pays off in a few situations. Under trees, where sap and leaf litter build up. Near a farm, a busy main road or a building site, where dust and grime bond to the glass. On a shallow pitch below about 15 degrees, where water pools instead of running off. And anywhere with a bird problem, because droppings are acidic and don't wash off cleanly.
A properly soiled array can lose a noticeable chunk of output, so a clean can pay for itself in recovered generation, though how much you get back depends on your usage, generation and energy costs. On a clean, steep, tree-free roof in a rural village, a wash every three or four years is plenty.
One rule that matters more than the money: never go up there yourself. Falls from domestic roofs are one of the most common serious accidents in UK home maintenance. Also skip pressure washers and detergent, both of which can force water past the panel seals and void the product warranty.
What does it cost to replace a solar inverter?
£500-£2,500 fitted, and this is the one big-ticket item you should genuinely plan for.
The inverter is the only component in a solar system doing hard electrical work every daylight hour, and it's the part that tends to fail first. Most string inverters carry a 5-12 year warranty, while the panels above them are warranted for 25. Do that arithmetic and you can see one or two replacements coming across the system's life.
| Inverter type | Replacement cost fitted |
| Standard string inverter (3-5kW) | £500-£1,200 |
| Hybrid or battery-ready inverter | £1,000-£2,000 |
| Premium or optimiser-compatible | £1,200-£2,500 |
If you're choosing a system now, a longer inverter warranty is worth paying a bit more for. Our guide to solar inverters covers the differences.
How much is bird proofing for solar panels?
£300-£1,000 for a standard domestic array.
The gap between panel and tile is a warm, sheltered, predator-free cavity, and pigeons love it. Once they nest you get droppings down the roof, blocked gutters, chewed cable insulation and a genuine fire risk from nesting material sitting on DC wiring.
The Independent puts UK bird proofing at £300 to £800 for a standard residential system, with other installers quoting up to £1,000 on larger or harder-to-reach arrays. Mesh clipped to the panel frames is the standard fix, and it should never be screwed or drilled into the panels themselves.
Timing matters legally, not just practically. Under the Wildlife and Countryside Act 1981 it's an offence to intentionally damage or destroy the nest of any wild bird while it's in use or being built. In practice that means proofing work happens outside the main nesting season, roughly March to August, or you wait until the birds have finished and fledged. A contractor who offers to clear an active nest in June is offering to break the law on your behalf.
What's covered by warranty, and what isn't
Three separate warranties usually apply, and people mix them up constantly.
The product warranty on the panels covers manufacturing defects, typically 10-25 years depending on brand. The performance warranty guarantees output, normally around 0.5% degradation a year, leaving roughly 87-90% of original output at year 25. The workmanship warranty from your installer covers the fitting itself, commonly 10 years on an MCS installation.
None of them cover cleaning, bird damage, storm damage or general wear. Storm and impact damage usually falls to your home insurance instead, and it's worth checking your policy actually lists the panels.
Claiming on a performance warranty needs evidence, which means monitoring data. That's a decent argument for keeping your app connected and taking monitoring seriously rather than ignoring it for five years.
What can you do yourself for free?
More than you'd expect, and none of it involves a ladder.
Check your monitoring app once a month and compare output to the same month last year. A sudden drop of 10% or more on a clear day means something has changed. Look at the array from the ground with binoculars in spring for nesting material or lifted panels. Clear the gutters below the array, since overflow running back under the tiles causes more expensive damage than dirty glass ever will. Keep an eye on trees to the south of the roof, because ten years of growth turns a clear roof into a shaded one very gradually.
Learning to read the generation curve is the highest-value thing on that list. We wrote a beginner's guide to reading your monitoring app and a longer piece on diagnosing faults from monitoring data.
Watch out for the "mandatory annual service" call
There is no legal requirement to service a domestic solar PV system, and no MCS rule that forces you into an annual contract.
Cold callers claiming your panels are "due a compulsory safety inspection" or that your warranty is "about to be voided" are a persistent problem in the UK solar market, often targeting homeowners with older systems still on Feed-in Tariff payments. Servicing is genuinely a good idea. Being told it's compulsory is a sales tactic.
Before agreeing to anything, check the company on the MCS installer database, ask which specific warranty they claim is at risk, and get the price in writing before anyone climbs on your roof.
A realistic 25-year maintenance budget
Adding the components up for a standard two-storey domestic array gives you a working figure to plan around.
| Item | 25-year total |
| Cleaning, every 2 years at £140 | ~£1,700 |
| Electrical service, every 3 years at £160 | ~£1,300 |
| Inverter replacement, one or two | £500-£2,500 |
| Bird proofing, if needed | £0-£1,000 |
| Rough total | £3,000-£6,000 |
Set against a system that should still be producing around 88% of its original output at year 25, the running costs are modest. They just aren't zero, and anyone telling you solar is completely maintenance-free is overselling it. Our piece on how long solar panels last in the UK goes into the lifespan side in more detail.
Getting it looked at properly
CRG Direct services and repairs domestic solar systems, including ones we didn't install. That covers electrical testing, inverter diagnostics and replacement, bird proofing, and monitoring setup for systems where the app was never configured properly in the first place.
If you'd rather catch problems before they cost you, we also run a proactive monitoring service that flags underperformance automatically instead of waiting for you to notice it on a bill.