As the global push for renewable energy accelerates, solar photovoltaic (PV) systems have become a
cornerstone of clean and sustainable electricity generation. However, the actual performance of these
systems often falls short of their theoretical potential. One key reason lies in environmental and
meteorological factors—many of which are becoming more pronounced with climate change. This
article explores how weather-related losses affect PV system efficiency, highlighting key loss factors
with real-world data and placing particular emphasis on the role of heatwaves and related climate
extremes.
Understanding PV System Losses
A typical PV system begins with a theoretical performance ratio (PR) of 100%, assuming ideal
conditions. Yet in practice, various loss mechanisms gradually degrade this efficiency. Using a
breakdown derived from solar-repository.sg, we analyze a typical loss profile:
Loss Category Efficiency After Loss (%) Individual Loss (%)
Soiling (dust, debris) 99.0 1.0
Reflection loss 95.8 3.2
Spectral mismatch 94.5 1.3
Irradiation variability 91.9 2.6
Temperature effects 84.1 7.8
Mismatch and circuitry losses 83.3 → 81.2 ~2.1
Transformer and inverter loss 81.2 → 80.5 0.7
Final Estimated PR 80.5%
Among all, temperature-related losses represent the single largest drop in performance,
underscoring a growing concern in the era of climate change.
The Climate Connection: Heatwaves and Performance Degradation
Rising global temperatures and the increasing frequency of heatwaves have a direct and measurable
effect on solar performance. While sunlight is essential, extreme heat actually reduces the electrical
efficiency of PV modules. Crystalline silicon panels, for example, experience an efficiency drop of
approximately up to 0.4–0.5% for every °C above 25°C.
During prolonged heat events, surface module temperatures can exceed 60–70°C, leading to double-
digit performance losses—far greater than those from soiling or shading. Additionally, heat-induced
degradation affects not only power output but also shortens the lifespan in system components such
as inverters and transformers.
Meteorological Uncertainty: Clouds, Aerosols, and Storms
Other weather-related effects include:
● Increased cloud variability due to shifting atmospheric circulation patterns, reducing
irradiation consistency.
Created for SolarVision.org
● Dust and aerosol loading, especially in arid regions or during wildfires, exacerbating soiling
losses and spectral mismatch.
● Severe storms and hail events, leading to physical damage or emergency shutdowns.
These elements not only contribute to routine operational losses but also raise risks for downtime
and maintenance costs, both of which affect long-term energy yield and return on investment (ROI).
Mitigation and Adaptation Strategies
To deal with climate-related PV performance degradation, system designers and operators are
employing multiple strategies:
● Bifacial modules to leverage reflected light.
● Active cooling or optimized ventilation to limit temperature buildup.
● Real-time performance monitoring using meteorological inputs.
● AI-driven forecasting models to predict and adapt to weather-driven losses.
Conclusion
As the energy sector pivots toward carbon neutrality, it must contend not only with building more solar
infrastructure but also with making it resilient to climate extremes. A deeper understanding of
meteorological impacts—especially temperature-driven losses—will be crucial to achieving consistent,
reliable performance from PV systems in a warming world.