Introducing a bold idea: night-time solar power for satellites
Sunlight, a defining feature of Australia’s landscape, is not just a daytime resource. In Sydney, researchers are exploring how to capture solar energy when the sun sets and then deliver it to orbiting satellites or other space-based platforms. The concept combines cutting-edge energy storage, innovative conversion technologies, and the long-term goal of creating a constant energy supply that transcends day and night.
How night-time solar could work
The key challenge is storage and transmission. Solar farms today generate power during daylight hours, but demand and opportunity extend into the night and into the orbiting realm through satellites that require reliable, uninterrupted energy. Scientists are investigating several pathways:
- <strong Thermal storage: Excess daytime energy can heat molten salts or other phase-change materials. When energy is needed, the stored heat drives turbines to produce electricity, which can then be used to power ground stations or beamed to space.
- <strong Green hydrogen and synthetic fuels: Surplus solar power can split water to create hydrogen. This hydrogen can later be used to generate electricity or power propulsion systems for space platforms, offering a versatile energy currency for night-time needs.
- <strong Energy beaming concepts: In the longer term, low-power, safe energy beaming from Earth to space could provide a fallback for satellites. While still experimental, such ideas emphasize a future where satellites rely less on their own finite onboard power.
These approaches require robust infrastructure, from efficient energy storage materials to high-reliability transmission systems. The Australian research community is uniquely positioned to push these concepts forward with strong solar resources, advanced materials science, and close collaboration with space agencies and industry partners.
Why satellites need a steady power source
Satellites in low Earth orbit experience periods of darkness and sunlight as they travel around the planet. To maintain consistent operations—such as Earth observation, communications, and navigation—satellites must withstand power fluctuations. A more reliable energy strategy could extend mission lifetimes, improve data quality, and enable new capabilities like longer observation windows or more powerful sensors.
From research labs to potential applications
Sydney’s solar science community is testing materials, storage, and conversion systems that could underpin future space-grade energy solutions. Demonstrators may include pilot solar farms paired with high-efficiency batteries, as well as prototypes that convert daytime solar heat into storable energy for nighttime use on the ground or in nearby space platforms via planned beaming technologies. The collaboration across universities, startups, and government bodies aims to turn theoretical concepts into practical, scalable solutions.
What this means for Australia and the world
Developments in night-time solar energy are not just about space; they reflect a broader push toward resilient, round-the-clock renewables. If Australia can demonstrate reliable storage and transmission models for space-ready energy, it could accelerate the global transition to stable solar power and inspire new satellites, communications networks, and even space-based energy infrastructure in coming decades.
Looking ahead: challenges and opportunities
Major hurdles remain. Safety and regulatory frameworks for energy beaming technologies, the cost of advanced storage materials, and the alignment of terrestrial and space energy systems all require careful planning, thorough testing, and international collaboration. Nevertheless, the drive to make night-time solar energy viable for satellites signals a bold direction for renewables: energy that doesn’t stop when the sun goes down and a future where Earth-based solar resources support operations beyond our atmosphere.
As research progresses in Sydney and beyond, the world watches how daytime sun, smart storage, and space-compatible energy systems may eventually work together to power satellites—and perhaps redefine how we think about solar energy in the 21st century.
