Airbus works with researchers at Swansea University to investigate the performance and stability of perovskite solar cells in a simulated stratospheric environment.
Following a successful application to Airbus Endeavr, researchers at Swansea University’s College of Engineering were commissioned to investigate the performance and stability of pervskite solar cells in non-standard atmospheric conditions with air mass 0 illumination, low pressure and high temperature variations.
Dr Chung Tsoi, Senior Research Officer at Swansea University said, “The specific aim of this Airbus Endeavr funded research was to investigate the performance and stability of perovskite solar cells in a simulated stratospheric environment. This is at an altitude of twenty one thousand (21,000) metres where high-altitude pseudo-satellites – or what are known as HAPS – typically fly.”
High-Altitude Pseudo-Satellites (HAPS) are unmanned airships, planes or balloons flying in the stratosphere, operating like satellites but closer to the earth. They are powered exclusively by solar energy and are able to continuously fly for months. Solar panels integrated onto the wings and body directly power the aircraft engines and instrumentation, while secondary batteries charged in daylight power the flight during the night.
One key advantage of Perovskite solar cells (PSCs) is that they can be fully printed at low cost and low temperature on light-weight flexible substrates, such as plastic, and they can deliver much higher power-per-weight compared to current state-of-the-art space solar cells.
Dr Jérémy Barbé, Research Officer at Swansea University explained, “Through this research, we particularly wanted to better understand the effect of large temperature variations, low pressure and a higher level of UV light on the efficiency and stability of the solar cell. We also developed flexible perovskite cells with a higher power-per-weight than conventional space solar cells.”
The research found that:
- The power conversion efficiency, known as PCE, is optimised at low temperature
- A maximum efficiency of 18.2 percent under extra-terrestrial illumination – known as AM0 solar spectrum – was reached at -20°C, which is typical of the stratosphere during the daytime.
- Perovskite solar cells, known as PSCs, retain a high AM0 PCE of 17.2 percent at -50°C.
- This low temperature of -50°C can be found in the tropopause – the boundary between the troposphere and the stratosphere – or during the early or last hours of the day in the stratosphere. This means that PSCs can generate power for a longer time during the day and mitigate the use of batteries.
- PSCs can also withstand temperature cycles between +20°C and -85°C in the dark without any loss in performance. This means that these solar cells do not degrade because of because of variations in temperature between day and night.
- PSCs are stable for more than 25 days and retain approximately 80 percent of their initial power conversion efficiency (PCE) under LEDs illumination.
In addition, the research team were able to successfully manufacture flexible perovskite solar cells with a high efficiency of 17 percent* – one of the highest efficiencies demonstrated (to date) for flexible perovskite cells. [*This figure corresponds to a high specific power of 0.6 W/g]
The research results are encouraging:
Claus Zimmermann, Senior Expert Photovoltaic Power Systems at Airbus Defence and Space said, “This is an exciting project for Airbus, with the Airbus Endeavr funded research and technology project demonstrating that a flexible perovskite solar cell can be manufactured with a high energy efficiency.”
Wolfgang Pecher, Technology Domain Manager at Airbus Defence and Space added, “With a growing demand from potential customers and their end-users to use HAPS to extend their internet services and data activities, we’ve been encouraged by the results.”
Thanks to Airbus Endeavr funding, academic researchers based in Wales have worked closely with Airbus to undertake early stage research that has the potential to address a real-world challenge faced by the aerospace industry. The aim is to ensure that the project delivers tangible outcomes that deliver measureable impacts.
Nick Crew, Research and Technology Manager at Airbus and Chief Operations Officer for Airbus Endeavr Wales, concluded: “This innovative proof-of-concept project is the first step towards developing a perovskite solar cell solution for high-altitude pseudo-satellites and target applications.
“We’re looking forward to working with our industry and academic partners to identify follow-on funding – from Airbus or other interested parties – to develop the initial research idea into an innovative and commercially viable product that can be delivered at industrial scale.”