Companies are betting on perovskite solar cells to revolutionize the renewable energy industry, but challenges remain.
In the outskirts of Brandenburg an der Havel, Germany, a small factory is quietly producing solar cells using perovskites, a promising photovoltaic material that could transform the green energy landscape. Oxford PV, a UK firm, is one of many companies betting on perovskites to push the global transition to renewable energy into overdrive. These perovskite solar cells, when layered on top of traditional silicon cells, can potentially deliver at least 20% more power, making them an attractive option for urban areas and industrial sites with limited space. However, despite the excitement surrounding perovskites, the industry faces significant challenges in terms of stability and competition from the well-established silicon solar cell market.
The Reality Behind Perovskite-Silicon Tandems
Perovskite-silicon tandems have garnered attention for their potential to significantly increase the efficiency of solar panels. By layering perovskite on top of silicon, each material can absorb energy from different wavelengths of sunlight, resulting in higher power output. While some niche perovskite-based PV products are already on the market, the commercial production of perovskite solar panels is still in its early stages. Oxford PV plans to release its solar panels made from perovskite cells to end users next year, and other companies, such as Hanwha Qcells, have also announced plans to invest in pilot production lines. However, the industry still faces challenges in terms of stability and cost-effectiveness.
The Challenge of Stability
One of the major challenges facing perovskite solar cells is their stability. Perovskites have shown to degrade more quickly than silicon when exposed to moisture, heat, and light. While Oxford PV claims to have overcome this issue through private research, stability remains a key challenge for commercial manufacturing. Researchers are working on fine-tuning the composition and adding protective layers to improve the stability of perovskite cells. The European Union’s PEPPERONI project aims to develop tandem modules that operate reliably for over 30 years. Accelerated aging tests have shown promising results, but long-term outdoor testing is still needed to assess the true durability of perovskite-silicon tandems.
The Dominance of Silicon
Despite the potential of perovskite solar cells, some analysts argue that they may be largely irrelevant to the growth of solar power in the short term. Silicon solar cells have become incredibly cheap and efficient over the past decade, and the silicon PV industry is projected to meet the rising demand for solar installations. Silicon modules currently offer warranties of at least 80% of their original performance after 25 years, making them a reliable and cost-effective option. The perovskite products currently on the market offer relatively low efficiency and short lifetimes, making them less attractive to consumers. The challenge for perovskites is to prove their long-term stability and cost-effectiveness compared to silicon.
The Promise of Tandem Cells
Proponents of perovskite-silicon tandems argue that they offer superior performance to silicon cells and have the potential to revolutionize the solar power market. Tandem cells can potentially achieve an efficiency of 45%, compared to the theoretical maximum of 29% for silicon cells. The additional power density offered by tandems could be particularly attractive for homeowners with limited rooftop space. Tandem cells could also be used to power heat pumps, electric vehicles, and other energy-intensive applications in increasingly electrified homes. However, the success of tandems depends on overcoming stability challenges and reducing manufacturing costs to compete with silicon.
The Road Ahead
The future of perovskite solar cells remains uncertain. While the technology has shown remarkable improvements in efficiency, commercial-scale production and long-term stability are still major hurdles. Companies like Oxford PV and Qcells are working towards gigawatt-scale production, which would significantly reduce manufacturing costs and make perovskite-silicon tandems more competitive. European and US academic-industry partnerships are also driving research and development efforts. However, the dominance of the silicon PV industry and the need for extensive grid infrastructure and affordable energy storage are equally important factors in the global expansion of solar power. Whether perovskite solar cells can truly revolutionize the industry remains to be seen.
Perovskite solar cells hold great promise for the renewable energy industry, offering the potential for higher efficiency and power density. However, challenges related to stability and competition from well-established silicon solar cells still need to be overcome. While perovskite-silicon tandems have shown remarkable improvements in efficiency, their commercial viability and long-term stability are yet to be proven. The future of perovskite solar cells depends on achieving large-scale production, reducing costs, and demonstrating their durability in real-world conditions. Whether perovskites will truly revolutionize the solar power market or remain a niche technology is a question that only time will answer.