Thin-Film Amorphous Silicon PV: An Emerging Solar Option for the UK
Beyond conventional crystalline silicon panels, thin-film solar photovoltaic (PV) technologies are gaining attention among UK homeowners and businesses. Require less silicon than crystalline PVs, thin-film products are lightweight, flexible and potentially affordable alternatives. Amorphous silicon thin-film in particular holds promise but its suitability for the UK climate remains less proven. This article provides an in-depth look at the pros, cons and considerations.
What is Amorphous Silicon Thin-Film PV?
Amorphous silicon (a-Si) thin-film PV cells are produced by depositing a thin layer of hydrogenated amorphous silicon directly onto a substrate like glass, stainless steel or plastic rather than slicing wafers from a silicon ingot. This eliminates silicon waste during manufacturing and substantially lowers the amount of raw silicon required compared to crystalline PV, reducing production costs.
However, the random atomic structure of the amorphous silicon results in lower conversion efficiency ratings of 6-9% typically. And being thinner, more space is needed than conventional PVs to achieve the same wattage. Efficiency degradation over time due to the Staebler-Wronski effect also remains a challenge. Let’s analyze in detail the current pros and cons of a-Si thin-film solar for UK buyers.
Potential Benefits of Amorphous Silicon PV Lower Upfront Cost Eliminating silicon waste and requiring 95% less silicon feedstock than crystalline manufacturing, amorphous silicon modules cost substantially less to produce. This allows manufacturers to sell a-Si panels and complete PV systems at lower price points, increasing affordability. Amorphous silicon PV costs 40-50% less than crystalline counterparts today.
Better Low Light Performance
While having lower peak efficiency, amorphous silicon performs far better than crystalline panels under cloudy, overcast or winter conditions. The technology is less sensitive to reduced illumination, maintaining higher output than crystalline PVs under the UK’s frequently dim sunlight.
Better Shade Tolerance
Related to their low light resilience, a-Si cells are highly shade tolerant. Small sections of shading on a panel have minimal impact on overall performance thanks to the monolithic integration of thin-film cells. This makes amorphous silicon versatile for sites with obstructed sun exposure.
Lightweight and Flexible
Weighing under 10kg for 60-cell panels, amorphous silicon modules are over 50% lighter than crystalline equivalents. This simplifies handling, transport and roof loading. The thin-film can also be deposited onto flexible plastic substrates, enabling innovative bendable solar applications not possible with rigid crystalline silicon.
Aesthetic Versatility
Thin, lightweight a-Si panels enable unique designer possibilities like semi-transparent windows or colorful custom tints. This aesthetic flexibility and the lightweight structure facilitate building-integrated PV applications not achievable with heavy glass-fronted crystalline panels.
Potential Weaknesses and Considerations
Efficiency Limitations Despite recent improvements reaching over 13%, amorphous silicon efficiency remains well below crystalline PV. This means larger array sizes are needed to match the wattage output of conventional silicon panels, increasing space requirements and system costs.
Staebler-Wronski Effect
Prolonged sunlight exposure degrades a-Si cell performance through breaking weak silicon bonds, progressively reducing efficiency in the first months after installation. Output eventually stabilizes but can deteriorate faster in hot climates. While manufacturers have developed stabilization techniques, light-induced degradation remains a concern.
Untested Long-Term Reliability
With only 45 years of manufacturing history compared to over 60 for crystalline silicon, uncertainties exist about thin-film PV durability over decades in the field. However, studies suggest a-Si panels may maintain over 80% of initial performance after 30 years, on par with crystalline silicon.
Limited Recycling Options
End-of-life recycling processes for thin-film PV waste remain underdeveloped compared to crystalline silicon panel recycling. More work is needed to establish efficient a-Si decommissioning and reclamation.
Lower Lifetime Energy Yield
Due to lower wattage per panel and efficiency degradation, total lifetime electricity generation from amorphous silicon arrays is reduced compared to crystalline silicon. Factoring in the UK’s climate, a-Si thin-film may produce 10-15% less long-term yield for the same installed capacity.
Key Considerations for UK Solar Buyers
When assessing suitability for a residential or commercial solar installation in Britain, keep these amorphous silicon solar analytics in mind:
- Prioritize cost-effectiveness over peak efficiency ratings. Lower capital outlay can outweigh output trade-offs.
- Analyze projected long-term yields accounting for degradation. Lower on-paper efficiency may outperform in real-world UK conditions.
- Consider improved low light and shading tolerance benefits for overcast or obstructed locations.
- Factor in added space requirements for matching crystalline silicon wattages.
- Scrutinize manufacturer financial stability and ability to honor long warranties.
- Verify reputable installer expertise with thin-film PV specifics like wiring configurations.
The Outlook: Prospects for Amorphous Silicon PV in the UK
Amorphous silicon thin-film has intriguing advantages that make the technology worth evaluating for large- and small-scale solar projects in Britain. Decades of improvements have enhanced a-Si efficiency and stabilization while retaining benefits like lightweight flexibility and low-light performance. Yet concerns remain about lifetime degradation and energy yields compared to proven crystalline PV.
For UK homeowners and businesses considering solar, amorphous silicon thin-film may represent a viable lower-cost alternative but thorough analysis is required to determine if potential trade-offs are acceptable. As manufacturers continue honing a-Si efficiency, reliability and cost-competitiveness, the technology appears poised for expanded adoption in Britain’s solar energy market. But more field experience locally is still needed to ascertain its suitability for the UK climate. For now, crystalline silicon likely remains the safer bet for most buyers.
