ASTRAL: Advanced Solar Cells with Thermal, Radiation, And Light Management for Space-Based Solar Power

Space-Based Solar Power (SBSP) aims to transmit clean, near-continuous, and gigawatt-level power to our planet from PV stations in space, unhindered by meteorological conditions or nighttime. Among the various challenges for SBSP, the development of ultra-lightweight PV technologies with high specific power (energy-to-weight ratio) is imperative to maximize on-orbit power collection whilst minimizing launch and production costs. Additionally, it is of interest to develop PV technologies that can survive the elevated radiation levels of high-altitude orbits, which are relevant for SBSP as they enable continuous ground coverage and uninterrupted power transmission from space. Here we present Advanced Solar cells with Thermal, Radiation, And Light management (ASTRAL), a concentrator PV design for SBSP. ASTRAL consists of a radiation-resilient ultra-thin InGaP/GaAs tandem solar cell, coupled to a rear reflector and nanophotonic texture for light-trapping, and to a front dielectric coating for antireflection and thermal management. Through rigorous thermal, radiation, and optical device modelling, we demonstrate that ASTRAL enables i) radiation tolerance, offering decades-long lifetimes in high-altitude orbits, ii) high specific power and low weight, significantly reducing launch costs, and iii) state-of-the-art passive cooling, providing regulated operating temperatures under concentration. By bridging these key functionalities in a single PV design, ASTRAL has the potential to advance SBSP towards a feasible platform for solar energy harvesting. This work is supported by the UK’ Department of Energy Security and Net Zero.