PV Retrofit Performance Improvement – Long-Term Field Results
Ultrathin SiO₂ Functional Coatings for Efficiency Improvement of Existing Solar Plants
Overview
Improving the performance of existing photovoltaic installations has become an increasingly important part of global solar development. While new solar parks continue to be built worldwide, a large share of installed photovoltaic capacity consists of systems that have been operating for many years.
Many of these installations remain technically sound but experience avoidable energy losses caused by reflection, surface contamination and environmental exposure.
Long-term field observations show that ultrathin SiO₂-based functional coatings applied to photovoltaic glass surfaces can measurably improve energy yield without requiring any modification of electrical or structural components.
This non-invasive retrofit technology enables performance improvements in operating solar plants and can be implemented without module replacement or system redesign.
Global Potential of PV Retrofit Technologies
Global photovoltaic capacity has reached the terawatt scale, with a significant share of installations built between 2000 and 2015.
These systems often continue to operate reliably but show measurable efficiency losses due to:
- reflection losses at the glass surface
- accumulation of dust and airborne particles
- uneven wetting behaviour
- thermal stress
Retrofit technologies that modify only the glass surface provide a practical method to improve system performance without replacing modules or changing electrical infrastructure.
This approach is particularly suitable for utility-scale solar plants.
Technology Principle
Ultrathin SiO₂ functional coatings modify the surface energy of photovoltaic glass at the nanometre scale.
The coating forms a permanently bonded functional glass surface with the following effects:
- improved light transmission
- reduced reflection losses
- improved utilisation of diffuse light
- reduced dirt adhesion
- improved natural cleaning behaviour
Because only the glass surface is modified, electrical and mechanical properties remain unchanged.
The technology can be applied both to new installations and to existing solar plants.
Long-Term Field Results
Long-term field measurements in different climate zones demonstrate consistent performance improvements.
Typical observations include:
Optical Base Effect
Improved light transmission typically results in:
High Soiling Environments
In dusty environments, combined optical and anti-soiling effects can result in:
Higher values have been observed under extreme environmental conditions.
Performance Stability
Multi-year observations show stable performance improvements over time.
Performance improvements are typically most visible:
- in morning and evening hours
- under diffuse light conditions
- during variable weather conditions
These observations confirm improved utilisation of diffuse solar radiation.
Influence on Soiling and Cleaning
Surface contamination is one of the main causes of energy loss in photovoltaic installations.
Functionalised glass surfaces significantly reduce particle adhesion.
Field observations indicate:
- extended cleaning intervals
- stable surface transparency
- reduced water consumption
- lower maintenance effort
In dry regions, natural cleaning by wind and rain can remove a large proportion of loose particles.
These effects are particularly relevant for large solar parks.
Industrial Applications
The technology has been applied in operating solar plants in different regions.
In parts of Asia, surface functionalisation is increasingly integrated into regular maintenance cycles of solar parks.
Application can be performed without dismantling modules and without interruption of plant operation.
This allows efficient implementation even in large installations.
Safety and Material Compatibility
Ultrathin functional coatings do not affect electrical or mechanical safety of photovoltaic modules.
Investigations indicate:
- stable electrical parameters
- no mechanical stress on modules
- full compatibility with photovoltaic glass
The technology is suitable for long-term operation.
Economic Considerations
Even moderate improvements in energy yield can have significant economic impact in large solar installations.
Additional energy production combined with reduced cleaning requirements can result in attractive payback periods.
Retrofit technologies therefore provide an economically viable method to improve existing solar plants without major investment.
This is particularly relevant for:
- utility-scale solar parks
- high-dust environments
water-limited regions
