A Stellar Breakthrough in Solar Energy

In recent years, there has been a significant increase in the deployment of large space systems, marking a turning point in the course of space exploration and utilization. This trend is largely driven by an increasing demand for advanced communication networks, expanded satellite constellations, and ambitious space missions, which necessitate the construction of more massive and sophisticated space structures. However, this growth comes with a pressing concern: the growing energy requirements of these large space systems are beginning to outpace the capabilities of existing space-rated solar technologies.

Space-rated solar technologies, which have long been the primary source of power for satellites and space missions, are now facing limitations in meeting the growing energy demands of these expansive space projects. Traditional solar panels optimized for space applications, though efficient in converting sunlight into electricity, are constrained by their design and limited surface area. As the scale and complexity of space missions escalate, the need for more power-efficient and space-adaptive energy solutions has become increasingly pressing.

In addition to being capable of withstanding extreme temperature changes and high levels of ionizing radiation, future solar panels must be able to provide much higher specific powers, and at a significantly lower cost per watt. Being robust against the challenging environmental conditions found in space is especially important, considering the high cost of replacing panels that are already in orbit.

In response to this challenge, research and development initiatives have intensified, focusing on the innovation of novel energy technologies tailored specifically for large-scale space systems. Some very promising work has recently been published by a team led by researchers at the Centre for Solar Energy Research at Swansea University. They have developed a new type of solar cell technology that can produce more power than existing space-rated technologies. Moreover, they have conducted a six year study of their solar cells to see how well they perform in orbit.

The cadmium telluride-based solar cells sit on top of thin layers of various semiconductor materials. These layers were deposited onto a space-qualified cerium-doped alumino-silicate cover-glass. By leveraging this unique design, the team was able to produce the solar cells inexpensively, and critically, they are capable of providing much greater power output than present technologies. These characteristics could make this new system well-suited for the production of panels that cover a large area to provide large space systems with substantial amounts of energy.

To explore the real-world utility of the solar panels, the team deployed them on a CubeSat that was launched into a sun-synchronous orbit in 2016. Six years of data, consisting of 30,000 orbits, was collected and analyzed. It was discovered that not only are the panels still in operation, but they have not physically deteriorated under the harsh conditions of space. As is generally the case, however, the panels did become less efficient over time, producing less power output. The team intends to work toward mitigating this issue in the future, but in any case, they believe that their technology will be commercially viable based on the results observed so far.