Can night-time solar energy power satellites?
Solar energy is synonymous with daylight in Australia—glinting on water, warming the sand, and fueling homes and industry. But a growing line of research asks a bold question: can we harvest solar energy during the day, store it, and transmit enough power to satellites even when the sun is not shining? In Sydney, scientists and engineers are exploring pathways toward space-based power systems that could one day keep satellites powered around the clock.
The core idea: daytime capture, nighttime use
The concept hinges on robust energy storage and efficient transmission. Solar panels can convert sunlight into electricity, but solar output ends at sunset unless that energy is stored. Advances in batteries, thermal storage, or other reserve technologies could hold energy during peak sun hours and release it when needed—potentially for use in space or to beam power to orbiting platforms. While the practical realities are complex, the goal is clear: create a reliable bridge between daytime solar capture and nighttime or orbital power demand.
From Earth to orbit: how would it work?
Two broad approaches are often discussed in the space-power community. The first is an on-planet-to-orbit model, where energy is captured on Earth, stored, and then transmitted (via microwaves or laser beams) to satellites in precise, orbital corridors. The second, more ambitious concept imagines large-scale solar arrays in space, with energy generated in orbit and sent to Earth as needed. Both ideas would require breakthroughs in energy density, transmission efficiency, and safety, but researchers argue that a terrestrial precursor could test the critical components of the system before scaling to space.
Key challenges to solve
Experts point to several hurdles. First, storage technology must achieve high energy density with low losses over long periods. Second, wireless power transmission must be highly efficient and tightly controlled to avoid interference and safety concerns. Third, the infrastructure required to deploy and operate such systems—on Earth and potentially in orbit—demands substantial investment and international collaboration.
Why Australia could be a testing ground
Australia has a strong solar resource and a growing focus on renewable energy innovation. Sydney and other centers are home to researchers collaborating with universities and industry partners to prototype storage and transmission technologies that could support future space-based power networks. Demonstrations often start small: optimised battery systems, hybrid storage, and ground-based beaming experiments that validate control systems, safety protocols, and efficiency models. If successful, these tests could pave the way for pilot programs in which power is captured on Earth and directed toward satellites during orbital night.
Environmental and security considerations
Any plan to transmit significant energy wirelessly faces environmental and security scrutiny. Safety protocols, electromagnetic exposure limits, and potential ecological impacts must be addressed from the outset. Transparent risk assessments and robust regulatory frameworks will be essential as researchers move from laboratory tests to real-world demonstrations.
What this could mean for space and Earth energy use
Long-term, the ability to provide reliable, round-the-clock power for satellites could benefit Earth observation, telecommunications, and scientific exploration. It might also drive progress in energy storage and transmission that spills over into terrestrial grids, helping smooth demand peaks and reduce storage costs. For Australia, it signals a growing ambition to contribute to a global frontier where energy technology meets space technology.
Looking ahead
While night-time solar energy powering satellites remains a frontier idea, ongoing experiments in Sydney and beyond are laying the groundwork. The coming years will likely bring incremental milestones—from improved storage materials to more efficient wireless power transmission tests—that collectively push us toward a future where daytime energy could keep satellites powered after dark.
