Recent research from the University of New South Wales (UNSW) in Australia has raised significant concerns about the longevity of next-generation solar modules, highlighting how ultraviolet (UV) radiation could accelerate their degradation far beyond what current industry standards predict. This study, published in the IEEE Journal of Photovoltaics, introduces a groundbreaking global model that quantifies UV exposure for photovoltaic (PV) systems worldwide, revealing vulnerabilities particularly in advanced technologies like Tunnel Oxide Passivated Contact (TOPCon) and heterojunction (HJT) cells.

These next-gen solar modules, designed to achieve higher efficiencies by capturing a broader spectrum of sunlight—including UV light—promise to revolutionize renewable energy. However, their increased sensitivity to UV photodegradation poses a hidden risk, potentially shortening operational lifespans by 7 to 10 years in high-irradiance regions. As solar deployment scales globally, understanding these dynamics is crucial for ensuring reliable, cost-effective energy production.

Understanding Next-Generation Solar Technologies

Solar photovoltaic technology has evolved rapidly from traditional monocrystalline silicon panels, which typically degrade at about 0.5% to 0.9% per year, to advanced architectures. TOPCon cells feature a thin tunnel oxide layer and polycrystalline silicon passivation on the rear side, reducing recombination losses and boosting efficiency to over 25%. Heterojunction cells combine crystalline silicon with amorphous silicon layers, achieving efficiencies up to 27% in lab settings. These innovations make panels lighter, more efficient, and suitable for diverse applications, but they introduce new material interfaces prone to environmental stressors like UV light.

UV radiation, part of the solar spectrum below 400 nanometers, penetrates panel encapsulants and interacts with cell surfaces, triggering chemical bond breaking, defect formation, and carrier recombination. In step-by-step terms: (1) UV photons excite electrons in passivation layers; (2) this generates reactive species or hydrogen release; (3) defects accumulate, increasing surface recombination; (4) power output declines non-linearly over time. While older panels filtered much of this UV, next-gen designs absorb it for gain, inadvertently amplifying degradation.

UNSW's Innovative Global UV Exposure Model

Led by Dr. Shukla Poddar under supervisors Prof. Bram Hoex and Associate Prof. Merlinde Kay, UNSW engineers developed the first high-precision model for UV irradiance on tilted PV surfaces. Unlike horizontal measurements in standard datasets, this tool accounts for panel tilt, azimuth, tracking type, local aerosols, humidity, clouds, and ozone. Validated against European pyranometers and climate archives, it generates site-specific UV maps for developers.

The model reveals stark global variations: desert regions like Alice Springs, Australia, deliver UV doses equivalent to a full IEC 61215 certification test (15 kWh/m²) in just 30-40 days. Tropical areas follow closely, while temperate zones see lower exposure. "We've produced a global map that shows what you could expect depending on your location," Dr. Poddar explained.

Trackers vs. Fixed-Tilt: A Critical Comparison

Sun-tracking systems, optimizing yield by 20-40%, expose panels to up to 1.5 times more UV than fixed-tilt arrays. Single-axis trackers in high-UV zones suffer 0.35% annual degradation from UV alone—nearly double the 0.25% for fixed setups. Over 25 years, this compounds to 8-10% extra loss, eroding return on investment (ROI). Dr. Poddar notes, "Trackers get the maximum UV on top, making them more susceptible."

• Fixed-tilt: Optimized for latitude, lower UV dose, stable degradation.
• Single-axis trackers: East-west rotation increases front exposure.
• Dual-axis: Highest UV, rare but riskiest.

The 'Long Tail' Phenomenon in PV Degradation

Complementing the UV model, a January 2026 UNSW study analyzed 11,000 global panels, uncovering the 'long tail'—20% degrade 1.5x faster than average (1.35%+ annually), 8% at 1.8%+. Some reach 45% loss by year 25 or fail in 11 years. Causes include infant mortality (early defects), interconnected failures (moisture + cracks), and flaw accumulation—independent of climate.

PhD student Yang Tang highlighted: "One in five systems degrade at least 1.5 times faster... useful life closer to 11 years." This underscores UV's role within broader failure cascades.

Mechanisms of Accelerated UV Degradation

UV photodegradation involves hydrogen dynamics in passivation films. In TOPCon, UV breaks Si-H bonds, releasing hydrogen that migrates, creating recombination centers. Heterojunction amorphous silicon degrades via UV-induced densification. Real-world exposure far exceeds lab tests, with non-linear effects accelerating later.

1. UV absorption in encapsulant (EVA) or anti-reflective coating.
2. Photon energy breaks molecular bonds, forming radicals.
3. Defects trap charge carriers, reducing voltage/efficiency.
4. Cumulative effect: 25% of annual degradation in high-UV sites.

For context in Australia, with its high solar irradiance, these issues amplify, affecting large-scale farms in Queensland and NT.Read the full UNSW announcement here.

Industry Implications and Economic Impacts

Warranties assume 80-90% output at 25 years, but accelerated degradation risks financial shortfalls. In a 100 MW farm, 20% long-tail panels could slash yields by 5-10%, hiking levelized cost of energy (LCOE) 10-20%. Insurers and banks demand better predictions; UNSW's model aids this. High-UV sites like the Middle East or Australian outback face premium risks for trackers.

Stakeholders: Manufacturers must reformulate encapsulants (e.g., UV blockers); operators select resilient modules; policymakers update standards.

UNSW's Pivotal Role in PV Research

UNSW's School of Photovoltaic and Renewable Energy Engineering, home to world-record cells, drives innovation. With ACAP (Australian Centre for Advanced Photovoltaics), it leads stability studies, from perovskite tandems to field analytics. This research exemplifies university-industry collaboration, informing IEC standards and commercialization. Such efforts position Australian higher education as a global hub for sustainable tech careers.

Solutions and Mitigation Strategies

Short-term: UV-resistant coatings, thicker encapsulants, site-specific modeling pre-install. Long-term: Revised IEC tests (e.g., 100+ kWh/m²), AI-driven O&M for early detection. UNSW advocates climate-tailored accelerated testing. Examples: NREL's UV filters; Oxford PV's stable perovskites (though UV-sensitive).PV Tech analysis.

• Choose fixed-tilt in high-UV areas.
• Enhanced passivation (AlOx/SiNx stacks).
• Regular electroluminescence imaging.

Future Outlook for Solar Durability

By 2030, next-gen modules could dominate 50% market share, but stability is key to terawatt-scale PV. UNSW's tools enable precise forecasting, fostering resilient designs. Ongoing trials test self-healing silicon; tandem perovskites show promise if UV-stabilized. Australia's sunny climate makes UNSW ideal for real-world validation, benefiting global deployment.

Actionable insights: Developers, input site data into UV models; researchers, expand datasets; students, pursue PV engineering for impactful careers.

Photo by Wattmonk Technologies on Unsplash

Stakeholder Perspectives

Industry voices echo urgency: pv magazine notes tracker's double degradation risk. Experts like Dr. Poddar urge standards evolution: "New high-efficiency PV needs real-world reflection." Balanced view: Gains in efficiency offset risks with mitigations, sustaining solar's 80% cost drop trajectory.