Researchers affiliated with King’s College London have published a new modeling study showing that space-based solar power could supply up to 80 percent of Europe’s renewable energy by 2050, potentially cutting total electricity system costs by 7 to 15 percent under net-zero constraints. The findings land alongside a recent NASA assessment and years of European Space Agency investment, building a case that orbital solar farms could do more than help hit climate targets. They could deliver continuous clean electricity to places that ground-based grids struggle to reach.
Why Orbital Solar Beats Ground-Level Panels
The basic physics make the case. Every hour, more solar energy reaches Earth than humanity consumes in an entire year, yet about 30 percent of that energy bounces back into space before it can be captured. Ground-based solar panels face additional losses from weather, nighttime, and seasonal variation, problems that vanish in geostationary orbit where sunlight is nearly constant. A satellite parked 36,000 kilometers above the equator can harvest energy around the clock and beam it to receiving stations via microwave transmission, bypassing the intermittency that forces terrestrial grids to rely on expensive storage and backup generation.
That advantage is what makes space-based solar power attractive not just as a supplement to wind and solar but as a potential replacement for large shares of intermittent capacity. The King’s College London preprint, hosted on arXiv, integrates space-based solar power into a Europe-wide capacity-expansion and dispatch model under net-zero constraints. Under a low technology-readiness-level near-baseload design scenario, the model projects that orbital solar could reduce total system costs by roughly 7 to 15 percent, largely by displacing the need for massive overbuild of wind and ground solar that intermittent systems require.
NASA Flags Promise and Price Problems
NASA’s Office of Technology, Policy, and Strategy released its own official study on space-based solar power, and its conclusions are more cautious. The report finds that on a 2050 timeline, the studied SBSP cases remain more expensive than terrestrial sustainable alternatives. Emissions profiles, the agency notes, could be similar to ground-based renewables, meaning the technology does not offer a clear carbon advantage over well-deployed wind and solar on the ground. The cost gap is the central obstacle: launching, assembling, and maintaining kilometer-scale structures in orbit demands infrastructure that does not yet exist at commercial scale.
Where NASA sees real potential is in serving remote and underserved locations. Regions that lack robust terrestrial transmission infrastructure, from island nations to polar research stations, could receive beamed power without the expense of building long-distance grid connections. That use case reframes space solar not as a competitor to rooftop panels in Berlin or Madrid but as a tool for energy access in places where conventional renewables face logistical barriers. The distinction matters because it shifts the cost-benefit calculation: a satellite that costs more per kilowatt-hour than a German wind farm might still be cheaper than stringing cables across the Pacific.
Caltech Proved the Core Technology Works
The theoretical models gained real-world backing when Caltech’s Space Solar Power Demonstrator, known as SSPD-1, wirelessly transmitted power in orbit on March 3, 2023. The payload, launched aboard SpaceX Transporter 6 via a Momentus Vigoride transfer vehicle, carried three experiments: Alba, which tested different photovoltaic cell types; DOLCE, which deployed a lightweight foldable structure; and MAPLE, a flexible microwave power transmitter array. MAPLE achieved the key milestone, and by May 22, 2023, detectable power from the array had been beamed to Earth and confirmed on the ground.
That demonstration closed a gap between theory and engineering. Critics had long questioned whether microwave beaming could work reliably from orbit with lightweight, flexible hardware rather than the rigid, heavy antenna designs of earlier decades. SSPD-1 showed it could, at least at small scale. The jump from a laboratory-grade demonstrator to a gigawatt-class satellite delivering roughly 2 GW of power remains enormous, however. ESA-funded research by Frazer-Nash and the University of Strathclyde estimates that such arrays would require kilometer-scale structures with masses of roughly 2,000 to 10,000 tonnes, an assembly challenge with no precedent in space engineering.
Europe’s Cost-Benefit Math Points to Net Gains
ESA commissioned two independent cost-benefit analyses in early 2022, conducted by Frazer-Nash and Roland Berger, to test whether the economics could work at continental scale. Their base case scenario, involving 54 satellites deployed by 2070, produced estimated costs of 418 billion euros against estimated benefits of 601 billion euros, yielding a preliminary net value of 183 billion euros. Those benefits include avoided fuel imports, reduced need for grid-scale storage, and lower carbon abatement costs across the European energy system.
The King’s College London study adds granularity to that picture. Its modeling suggests space-based solar panels could provide 80 percent of Europe’s renewable energy by 2050, a figure that reflects not just raw generation capacity but the system-level value of near-baseload power that reduces reliance on backup gas plants and long-distance transmission upgrades. In the scenarios where orbital solar is deployed aggressively, it substitutes for large amounts of overbuilt wind and solar farms that would otherwise sit idle during periods of surplus generation, trimming total system costs even if each orbital kilowatt remains more expensive to build than a panel on the ground.
From Concept to Infrastructure
Translating that modeled promise into hardware will demand a broader ecosystem that extends well beyond a few demonstration satellites. Launch costs must fall further, in-space assembly and robotics have to mature, and regulatory regimes for beamed power will need to be hammered out. NASA’s broader science portfolio already documents how space-based observations transform understanding of our planet, from long-running Earth monitoring missions that track climate change to heliophysics research that studies the Sun as an energy source. Those same capabilities (precision pointing, large deployable structures, and high-reliability power systems) are directly relevant to building and operating orbital solar plants.
Space-based solar power would also plug into a wider exploration architecture that spans the solar system and deep universe, where spacecraft already rely on advanced solar arrays and power-beaming concepts for distant missions. Lessons from those programs, disseminated through platforms such as NASA Plus and its curated series, are gradually normalizing the idea that space infrastructure can serve not only scientific goals but also terrestrial energy security. For Europe, the emerging consensus from ESA studies, NASA assessments, and independent academic modeling is that orbital solar will not be a silver bullet or a cheap fix. Yet as part of a diversified net-zero strategy, targeted first at high-value, hard-to-serve markets and later at bulk power supply, it may become one of the more consequential space technologies of the mid-21st century.
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*This article was researched with the help of AI, with human editors creating the final content.
