Photovoltaics bets on perovskite cells

The size of the global solar photovoltaic and battery market has grown almost sevenfold since 2015, exceeding $550 billion, or about a third of the annual value of all natural gas produced globally. This dynamic, according to the Iea's new 'State of Energy Innovation' report, still has room for growth if a wider range of energy technologies are developed through stable demand, supported by 'pro-innovation policy regimes'.

Solar photovoltaics is one of the fastest-growing technologies expected between now and 2035, with the market set to triple in a decade. "The most competitive technology developers and manufacturers will reap significant benefits, benefiting the countries and regions where they are based," the report notes. "These virtuous mechanisms suggest that sustained demand will continue to reduce costs and improve the performance of energy technologies, allowing governments to focus their innovation efforts on other bottlenecks, particularly the availability of talented scientists and engineers and supply chain resilience," the Iea predicts. In a survey of international experts conducted at the end of 2024 for inclusion in the report, respondents identified batteries, solar energy and thermal storage as the areas that have made the most significant progress in recent years.

In terms of the most significant innovations in photovoltaics, the Iea cites the first commercial production of perovskite cells. "In 2024, scientists in Australia and the UK demonstrated for the first time the feasibility of a high-throughput production process for perovskite solar cells under normal environmental conditions, thus eliminating the need for a complex and expensive production step involving electrodes deposited in a vacuum. This overcomes a bottleneck for their industrial-scale deployment, bringing closer the large-scale deployment of this next-generation solar photovoltaic technology,' the Iea announced.

The report refers to the commercialisation of the first 72-cell panels from Oxford PV, an Oxford University spinoff that has built its first megawatt-scale pilot line in Brandenburg an der Havel, Germany, where it produces tandem, perovskite-on-silicon modules with an efficiency of 24.5 per cent, which is 20 per cent more efficient than a standard panel. Perovskite cells have a higher conversion efficiency and higher energy density than crystalline silicon, which means they take up less space for the same power and have a potentially cheaper and less energy-intensive production process. In addition, they are flexible, allowing for a wider range of applications than crystalline silicon. 'To further improve module efficiency, perovskites can be added to silicon cells, and in 2024 researchers in China successfully tested a tandem cell of this type with an efficiency of 34.6 per cent,' the Iea adds. Just at the beginning of April, Oxford PV signed a licence agreement with Chinese module manufacturer Trina Solar to manufacture and sell perovskite cells in China. Oxford PV holds the largest global patent portfolio for perovskite-based technologies and the agreement reflects the growing role of intellectual property transfer agreements in China.

Regarding the development of clean energy patents, today global patent applications on low-emission energy technologies are about twice as high as those on fossil fuels. Unlike in the US, where a quarter of energy patents relate to fossil fuels, almost all energy patents in China relate to low-emission energy (96% in 2022). Regional differences in the distribution of individual technologies are evident. In China, 18% of patent applications between 2020 and 2022 focused on energy storage, while 17% were related to solar technologies. In Germany, during the same period, 25 per cent of patents concerned energy storage and 23 per cent concerned electric mobility. Initial data on patent applications for 2023 globally indicate that energy storage continues to dominate, but in emerging markets (now largely emerged) solar is holding its own alongside storage.