Maintenance Guide · Owners
Solar Panel
Maintenance & Cleaning
What to check, when to clean, how to spot problems — and when your monitoring app is telling you something important.
How Much Does Dirt Reduce Output?
Clean panels outperform dirty ones — but the degree depends on what's causing the soiling. Research from the Energy Saving Trust and panel manufacturers gives these typical reductions:
| Contaminant | Output Reduction | Notes |
|---|---|---|
| General dust and grime | 2–5% | Largely removed by rain |
| Bird droppings (partial) | 5–10% | Even small areas cause disproportionate loss in string systems |
| Bird droppings (heavy) | 15–25% | Priority for cleaning — can hot-spot panels |
| Lichen/moss | 10–30% | Builds up over years; specialist treatment required |
| Seasonal pollution buildup | 5–15% | Worst in late winter; spring clean most valuable |
SolarEdge optimisation reduces the impact of partial shading from bird droppings by treating each panel independently. Systems without optimisers are more severely affected by localised soiling.
Annual Maintenance Checklist
Check monitoring app for unexplained generation dips
GivEnergy, SolarEdge, and Sigenergy apps show real-time and historical data. A persistent underperformance vs historical data signals a cleaning or fault issue.
Visual inspection from ground level
Look for obvious bird droppings, leaves, or debris accumulation. Inspect roof flashing and cable entry points for any visible damage.
Panel cleaning
Use deionised or soft water with a gentle brush. Never use abrasive materials or high-pressure washers directly on panels.
Inverter visual check
Confirm the display shows normal operation. Check for any warning lights or error codes. Ensure ventilation is unobstructed.
Battery visual check
Check for any swelling, unusual heat, or error codes. Confirm cables are secure and undamaged.
Professional annual check
Energy Concerns offers an annual maintenance visit for all systems we install — covering electrical connections, performance testing, and a written report.
Bird Proofing Solar Panels
Pigeons and starlings commonly nest under solar panels, causing significant soiling, blocking ventilation, and potentially damaging cables. Bird proofing — a mesh installed around the panel perimeter — prevents access under the panels and is a worthwhile investment for properties in urban areas.
Mesh proofing
Stainless steel mesh clips to the panel frame and closes the gap between panels and roof. Cost: £150–£400 depending on system size.
Spike strips
Physical deterrent installed around panel perimeter. Less effective than mesh but cheaper for short-term deterrence.
Winter Performance — What to Expect
UK solar panels generate electricity in all daylight conditions — including winter. December and January generate significantly less than June and July, but should not be zero. A well-functioning 4kW system in Leicester generates approximately:
December
~120 kWh
January
~140 kWh
March
~330 kWh
June
~490 kWh
Near-zero winter generation indicates a fault — contact Energy Concerns for a diagnostic check.
Annual Maintenance from Energy Concerns
We offer annual maintenance checks for all Energy Concerns installations, covering electrical safety, performance testing, monitoring setup, and a written condition report. We serve all locations across the East Midlands.
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