How dirt and soiling reduce your solar output — UK

Panel soiling — the accumulation of dust, pollen, bird droppings, and other debris — is one of the most common and fixable causes of solar energy loss. In arid regions, soiling alone can reduce output by 5–15%. Here's what you should know. This guide is tailored for UK solar owners, where maritime climate conditions and shorter daylight hours create different challenges.

Symptoms to watch for

Signs that this issue may be affecting your system

Panel soiling

Common

Dust, pollen, bird droppings, or debris accumulation reducing light absorption. More severe in arid or agricultural areas.

Loss: 215%Detection: visual

What you can check yourself

Actions you can take today without professional help

1

Panel soiling

Visually inspect panels from ground level. If you can see a visible film or debris, cleaning may restore 2–7% production.

When to get a professional inspection

Signs you need professional help

-Your system is over 7 years old and you've noticed a production decline
-Production has dropped more than 1% per year compared to year one
-Your system has experienced hail, storms, or physical damage
-You see visible damage: discolouration, bubbling, or cracked glass
-Your inverter shows frequent error codes or unexpected shutdowns

Expected inspection costs

Drone thermal audit

Most comprehensive option

Handheld thermal scan

Best for smaller systems

Electrical inspection

Inverter and wiring only

Find inspection providers

Is your system affected?

Use our free Solar Loss Checker to get a personalised diagnosis with an action plan.

Based on conservative solar performance modelling and published degradation data

NRELIEA-PVPSSunSpecPVsyst+ published research

Updated April 2026 · Structured performance modelling

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