Recently, we attended a thought-provoking webinar hosted by Sinovoltaics in collaboration with the University of New South Wales (UNSW). The topic was something that may not yet be a household name in the solar industry, but it soon will be: Ultraviolet-Induced Degradation (UVID).
With the rapid shift from PERC to TOPCon and HJT technologies, UVID has moved from a lab concern to a real-world reliability issue. The webinar, led by Prof. Bram Hoex (UNSW) and Nicholas Demar (Sinovoltaics), shed light on why UVID matters and what the industry is doing about it.
Why Should We Care About UVID?
When you invest in a solar project, you expect a 25+ year lifetime with predictable yields. But UVID threatens that equation:
- UVID causes a reduction in module voltage (Voc), leading to power loss.
- It affects not only the solar cells but also encapsulants, passivation layers, and other module components.
- Field studies show that UV exposure alone can cut power by over 6%, and when combined with damp heat, losses can exceed 25–30%.
That’s not a small margin — for a large-scale project, this translates into millions in lost revenue.
What the Webinar Revealed
1. Field Evidence is Clear
Electroluminescence (EL) and photoluminescence (PL) imaging confirm that long-term UV exposure leads to higher series resistance and reduced voltage. In other words, panels degrade faster than expected when exposed to UV and heat stress.
2. Metastability Complicates Testing
UVID is not static — it can worsen, recover partially, or shift over time, especially with cycles of light soaking and dark storage. This makes it difficult to measure consistently and highlights the need for better testing protocols.
3. Labs Are Overloaded
Accredited labs face long queues and fragmented protocols, delaying results for developers. Some EPCs have even resorted to using substitute UV tests just to keep projects moving.
4. Materials Matter
Research shows that thicker ALD AlOx layers provide better protection than thinner or PECVD versions. Innovative encapsulants that convert UV to harmless wavelengths are also promising.
5. The Push for Standards
Global institutions, including UNSW, are working toward new UVID testing standards that simulate 1–3 years of outdoor exposure. Importantly, the aim is not “test to failure,” but to flag risks early enough to safeguard long-term reliability.
Industry’s Practical Response
Sinovoltaics highlighted how they’re addressing the gap:
- Partnering with accredited labs worldwide.
- Offering fast-track UVID testing packages with no waiting queues.
- Already completing UVID testing for ~700 MW of projects in just the first half of 2025.
This is exactly the kind of proactive step the industry needs to maintain investor confidence.
The Bigger Picture
As solar becomes the backbone of global energy, reliability is non-negotiable. UVID may sound like a technical issue, but its impact is financial, operational, and reputational. If left unchecked, it could undermine trust in next-gen solar technologies.
At the same time, the good news is that the industry is not standing still. Researchers, testing labs, and companies like Sinovoltaics are moving fast to build standards, develop better materials, and ensure that UVID doesn’t catch the sector by surprise.
Our Reflection
The biggest takeaway from the webinar was this: Every leap in solar efficiency must be matched by equal attention to reliability.
UVID is a reminder that innovation brings risks, but with collaboration and robust testing, we can overcome them. As project developers, EPCs, and investors, the best thing we can do today is to ask hard questions about reliability validation before signing procurement deals.
Because in the end, performance is not just about day one output — it’s about delivering guaranteed yields for decades.