Solar power has become one of the most cost-effective and fastest-growing forms of electricity generation. But as deployment accelerates, the industry is approaching a new constraint. Conventional silicon solar cells are nearing their practical efficiency limits just as electricity demand rises and pressure grows to generate more power from constrained land and grid infrastructure.

Theoretical maximum efficiency for conventional silicon photovoltaic (PV) cells sits at around 29%. While leading commercial products are already approaching the upper end of that range, they are running out of headroom. Incremental improvements remain possible, but they are becoming harder and more expensive to achieve.

It is within this context that perovskite-based multi-junction solar cells have emerged as one of the most closely watched developments in renewable energy.

Why perovskites are attracting attention 
Perovskite materials have attracted global attention because they can capture sunlight more efficiently than conventional silicon alone. Unlike traditional solar cells, perovskites can be engineered at a molecular level to absorb different parts of the solar spectrum more effectively. When combined with silicon in tandem or multi-junction solar cells, this allows more of the sun’s energy to be converted into electricity from the same surface area.

Demonstrations of perovskite tandem solar cells have already exceeded 30% efficiency, with the potential to surpass 35%. Such advances represent more than a technical milestone. They could materially alter the economics of solar deployment.

Higher efficiencies would allow more electricity to be generated from the same surface area. For rooftop systems, this could improve energy self-sufficiency without requiring additional space. For utility-scale solar farms, it could reduce land-use requirements, infrastructure costs and accelerate return on investment.

The technology also offers advantages beyond efficiency. Perovskites are compatible with lightweight and flexible substrates, opening potential applications beyond traditional PV panels. Building-integrated photovoltaics could transform façades, windows and roofing materials into energy-generating assets integrated directly into urban infrastructure.

The challenge is now commercial readiness 
The potential of perovskite multi-junction solar cells is clear, but significant challenges remain before the technology can achieve widespread deployment.

The central issue is no longer laboratory performance. It is whether the technology can demonstrate long-term durability, scalability and bankability under real operating conditions.

Unlike silicon, which is chemically and structurally robust, perovskites are more vulnerable to environmental stress. Exposure to moisture, heat and prolonged ultraviolet radiation can degrade performance over time. While encapsulation techniques and material improvements are advancing rapidly, the industry still needs confidence that perovskite systems can operate reliably over the 25 to 30-year lifespans expected of commercial solar assets.

Manufacturing scalability presents another challenge. Much of the progress achieved so far has been in laboratory environments using fabrication techniques such as spin-coating that are unsuitable for industrial production. Commercial deployment requires processes capable of delivering consistent quality at high volumes and competitive cost.

Techniques such as vapour deposition, where ultra-thin perovskite layers are applied in controlled conditions, and roll-to-roll printing, which allows solar cells to be manufactured continuously at large scale, are being explored, but these must still be refined and validated at scale.

This is where independent testing, engineering guidance and certification frameworks become increasingly important. Organisations such as RINA play a role in helping emerging technologies demonstrate not only efficiency, but also long-term reliability, operational resilience and financial viability under real-world operating conditions.

Toxicity also remains a consideration. Many perovskite formulations contain lead, raising environmental and regulatory concerns. Research into lead-free alternatives continues, though these often involve trade-offs in performance.

Why Australia?  
Australia has emerged as one of the most strategically important environments for next-generation solar research and deployment. Its combination of high solar irradiance, geographically diverse climates and a rapidly evolving electricity grid with high penetration of renewables makes it an ideal testbed for next-generation photovoltaic technologies. Australia’s extreme climate, including intense UV exposure and demanding wind loads, enable accelerated degradation studies, providing insights into long-term performance that would take significantly longer to obtain in more temperate regions.

Government-backed initiatives played a decisive role in placing Australia at the forefront of next-generation solar. Funding from the Australian Renewable Energy Agency (ARENA) has supported the development of perovskite and tandem solar cell research, enabling institutions such as the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the University of New South Wales (UNSW) to advance work in stability, scalability and large-area manufacturing.

Beyond materials research, Australia is also at the forefront of system-level innovation. High penetration of PV and battery energy storage systems is driving research into grid-forming inverters, hybrid plant optimisation and system-strength remediation, all of which are essential for maintaining stability in increasingly renewable-dominated grids.

Emerging applications such as floating solar are also gaining traction, particularly across inland water bodies, expanding the scope of solar deployment in the region.

From RINA’s perspective, Australia represents an important bridge between laboratory innovation and commercially bankable deployment. The combination of advanced research capability, supportive policy frameworks and complex operating conditions makes the country strategically valuable in validating emerging solar technologies under real-world conditions.

What’s the next step for perovskite?  
The first phase of the solar transition focused heavily on reducing costs and scaling deployment. The next phase is likely to place greater emphasis on system integration, infrastructure constraints and energy density.

Higher-efficiency technologies such as perovskite multi-junction solar cells could help address some of these pressures by increasing output from constrained physical footprints while supporting a broader range of deployment models.

However, the industry should avoid assuming that strong laboratory performance alone guarantees commercial success.

Questions around manufacturing scale-up, certification standards, degradation rates, supply chains and environmental compliance remain unresolved. The sector has seen similar technology cycles before, where promising research outcomes did not automatically translate into durable commercial deployment.

Independent technical validation and certification will therefore play an increasingly important role in bridging the gap between scientific progress and industrial adoption.

Perovskite multi-junction solar cells represent one of the most promising frontiers in solar technology. But their long-term significance will depend less on efficiency records alone and more on whether the industry can successfully deliver reliable, scalable and bankable deployment at commercial scale.

The views and opinions expressed in this article are strictly those of the author only and are not necessarily given or endorsed by or on behalf of the Energy Institute.

• Further reading: ‘TNO develops perovskite solar roof tile’. TNO’s new perovskite based solar roof tile is claimed to demonstrate the integration of flexible PV modules onto curved roofing surfaces with minimal efficiency loss. Meanwhile, a new monitoring system that enables module-level fault detection in utility-scale photovoltaic plants is being developed by researchers at the Fraunhofer Institute in Germany.
• ‘Shining a light on solar capacity factors’. By 2029 solar PV is on course to be the largest source of renewable generation worldwide. But that does not mean all solar panels are as effective in generating power as others. Discover more about the solar capacity factors of the top 20 solar PV generating countries and the technologies being developed that could improve them.