UK · South West England

Solar panel degradation rates: what to expect in South West England

All solar panels degrade over time — it's unavoidable physics. The question isn't whether your panels are degrading, but whether they're degrading faster than expected. Published research shows median degradation rates of 0.5–0.8% per year, but real-world rates vary significantly by climate, panel quality, and installation conditions.

South West England has a maritime climate with 4.3 peak sun hoursper day. The UK's cooler temperatures benefit panel efficiency but shorter daylight hours affect annual output.

Related issues

Natural panel degradation

common

All solar panels lose efficiency over time at roughly 0.5–0.8% per year. Accelerated in extreme heat or poorly manufactured panels.

Typical loss: 315%

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Based on conservative solar performance modelling and published degradation data

NRELIEA-PVPSSunSpecPVsyst+ published research

Updated April 2026 · Structured performance modelling

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