The European Space Agency (ESA) has launched an ambitious initiative to harness the power of the Sun from space. The SOLARIS project aims to revolutionize solar power generation by deploying photovoltaic power plants in orbit, effectively addressing the limitations of ground-based solar energy.
This project is poised to explore innovative technologies that could transform the future of energy.
The grand vision behind SOLARIS
The SOLARIS project aspires to establish a space-based solar power system capable of generating energy 24/7, regardless of weather conditions.
“By positioning a solar power plant in space, in a geostationary orbit about 36,000 kilometers [22,369 miles] above the Earth’s surface, the solar panels would be exposed to sunlight and producing energy at all times of the day and in all seasons, except for a few days a year, near the equinoxes, when they might be in the cone of shadow generated by the Earth,” explains Nicola Rossi, Head of Innovation at Enel Group.
Analysts predict that solar capacity could reach 500 gigawatts, highlighting the urgent need for innovative solutions such as SOLARIS to sustainably meet future energy demands.
The technological challenges that this project faces
Developing a space-based solar power plant entails several challenges, mostly related to efficiency, cost, and logistics. According to Rossi, a one-gigawatt power plant could weigh around 11,000 tons, necessitating roughly 100 launches to assemble it in orbit.
To address these challenges, SOLARIS will utilize advanced materials, such as gallium arsenide and germanium, that allow for higher energy conversion efficiencies than conventional silicon-based panels.
“Current panels used in space achieve efficiencies on the order of 30% in converting sunlight to electricity, and in the next 20 years we expect them to reach 40%,” says Rossi.
The use of multi-junction solar cells—which can capture a broader spectrum of sunlight—will further boost energy generation. Additionally, SOLARIS envisions transmitting this energy back to Earth via microwaves, where it can be converted into electricity and integrated into the grid. The feasibility studies currently underway are crucial for assessing the project’s viability, with a decision expected sometime this year.
The role of collaboration in advancing SOLARIS
SOLARIS encourages collaboration among policymakers, energy suppliers, and space companies hoping to create a unified vision for space-based solar power. Sanjay Vijendran, ESA’s lead for the SOLARIS project, emphasizes the potential of this technology to provide clean energy at scale, which is vital for achieving carbon neutrality by 2050.
“Net zero presents many challenges, including the fluctuating outputs of current renewables like wind and ground-based solar farms,” Vijendran explains.
In addition to direct solar energy collection, ESA is investigating alternative methods, such as deploying large mirrors in space to improve the efficiency of terrestrial solar farms by reflecting sunlight down to them. This precursor technology could lay the foundation for more advanced systems while mitigating some of the technical obstacles with wireless energy transmission.
If the initial phase of SOLARIS proves successful, the project will move towards prototyping, with the goal of launching the first one-megawatt plant into orbit by 2030. Ultimately, the aim is to scale up to multi-gigawatt installations by 2040 to 2045, which could greatly contribute to global renewable energy targets. As Rossi observes, “A gigawatt of power installed in space produced six or seven times more energy than one installed on Earth.”
The SOLARIS project is both an innovative approach to energy production and a collaborative endeavor to combat the climate crisis. As ESA and its partners forge ahead, the vision of leveraging solar power from space could become a reality. This will surely mark a huge shift in humanity’s pursuit of sustainable energy solutions.