Scientists: Space-based solar could replace up to 80% of Europe's renewable energy. For now, it's only theory

According to a new study by scientists at King’s College London, space-based solar panels could theoretically replace up to 80 percent of Europe’s land-based renewable energy sources by mid-century. The technology has Czech roots and is based on NASA designs. The European Union even has a programme in this area, but major technical and economic obstacles must be overcome before the plan can become reality. 

Europe could theoretically obtain up to 80 percent of its renewable energy directly from space by 2050. This is according to a study by scientists at King’s College London, published in the scientific journal Joule. According to the authors, a system of space-based solar panels based on designs by the US NASA could also reduce the overall cost of Europe’s energy system by up to 15 percent and cut the need for battery storage by more than two-thirds.

The scientists created a detailed computer model of the European energy grid covering 33 countries, feeding in data on projected electricity demand, generation and storage capacity. They then incorporated the concept of so-called space-based solar power (SBSP). The results suggest that this technology could replace most land-based renewable energy sources, which today depend on changeable weather and the alternation of day and night.

The way SBSP works is highly complex, however, and for now remains science fiction. Huge solar panels would be placed in orbit, where they could generate electricity thanks to constant sunlight, regardless of the day-night cycle or cloud cover. The energy would be transmitted wirelessly to Earth via microwaves or lasers, where receiving stations would convert it back into electricity and feed it into the grid. The concept of space-based solar power also has Czech roots. It was first proposed in 1968, at the height of the space race, by Czech-American aerospace engineer Peter Glaser.

The technology is still far from practical use

The study emphasises that while land-based renewable energy sources provide intermittent output and require extensive energy storage capacity, space-based panels could operate as a stable, centralised source on a gigawatt scale. Nevertheless, the scientists warn that their model does not account for some specific challenges associated with operating in space, such as the risk of overcrowding in orbit, the possibility of an interruption to energy transmission or damage to satellites from space debris.

Alongside technical feasibility, however, cost remains the main obstacle. According to the authors, the technology could become economically competitive no earlier than around 2050. The cost of launching and maintaining satellites is currently many times higher than that of conventional solar or wind power plants. “There are certain risks that need to be considered, such as the possibility that a satellite in space could have too many panels and become a hazard to other objects in orbit,” said the study’s lead author, Wei He of King’s College London.

The European Space Agency (ESA) is exploring the subject through its SOLARIS project, which aims to test the first transmission of energy from solar panels in orbit back to Earth over the next decade.  The plan envisages an in-orbit demonstration around 2030, a first operational station in geostationary orbit by 2040, and the subsequent addition of further stations.