Space-based solar power stations have captured the attention of scientists and experts worldwide. The idea revolves around capturing solar energy in space and beaming it down to Earth, providing a continuous and sustainable source of clean electricity. Unlike Earth-based solar panels, space-based stations can continuously gather sunlight, unaffected by the setting sun, making them a promising solution for meeting clean energy demands.
Now, a study lead by Switzerland-based company Astrostrom, and part of the European Space Agency’s (ESA) Open Space Innovation Platform Campaign on “Clean Energy – New Ideas for Solar Power from Space”, is pushing the boundaries of this technology further. They have introduced a groundbreaking conceptual design called the Greater Earth Lunar Power Station (GE⊕-LPS), which could potentially supply electricity to future lunar settlements.
The GE⊕-LPS has butterfly-inspired design, with V-shaped solar panels with integrated antennas, forming a helix configuration spanning over a square kilometer. The ambitious project aims to deliver “megawatts of microwave power” to solar panel receivers on the lunar surface, generating a constant 23 megawatts of electricity for various lunar operations, including crewed bases.
One of the key advantages of the proposed design is its reliance on lunar resources, which could significantly reduce costs and eliminate the need to transport massive infrastructure from Earth. Cutting-edge solar panels based on iron pyrite monograin-layer solar cells would be manufactured using iron and sulfur recovered from the lunar surface.
If ESA’s SOLARIS R&D initiative confirms the feasibility of space-based solar power for meeting Earth’s clean energy needs, the concept of lunar-made solar power satellites could revolutionize the energy sector. Launching solar power satellites from the Moon into geostationary Earth orbit is considered a more practical option compared to launching them directly from Earth. Launching gigawatt-scale satellites from Earth faces significant challenges, including limited launch capacity and potential atmospheric pollution.
Sanjay Vijendran, overseeing the preparatory initiative SOLARIS, emphasized the scalability of the concept: “Once a concept like GE⊕-LPS has proven the component manufacturing processes and assembly concept of a solar power satellite in lunar orbit, it can then be scaled up to produce further solar power satellites from lunar resources to serve Earth.”
Furthermore, when compared to satellites launched from Earth’s surface, the lunar-made solar power satellites would require significantly less velocity change to be placed into geostationary Earth orbit. Sanjay further highlighted the numerous benefits of the project, “including the development of a cislunar transportation system, mining, processing, and manufacturing facilities on the Moon and in orbit, resulting in a two-planet economy and the birth of a spacefaring civilization.”
The strategic location chosen for the GE⊕-LPS is at an Earth-Moon Lagrange point situated approximately 61,350 kilometers from the lunar surface. Lagrange points are locations in space where objects can maintain a stable and stationary position. Notably, the station is envisioned not just as a power supplier but also as a habitat for astronauts, serving as a bridge-point between Earth and Moon operations, with some of its modules designed to provide artificial gravity, simulating Earth-like conditions for the well-being of future astronauts. Additionally, the station could act as a prototype for future space settlements in the cislunar space.
The feasibility study on the GE⊕-LPS concept shows promising results, suggesting that the construction of such a station would not require any major technological breakthroughs. Most of the core technologies for lunar surface mining, beneficiation, and fabrication are either in use or under development on Earth today. These existing technologies could be adapted and extrapolated to suit the lunar environment, delivered in modular form, and operated telerobotically on the Moon’s surface.
While the idea of space-based solar power is still in its early stages, researchers are making steady progress. By successfully beaming a small quantity of electricity from space to Earth with their prototype, Caltech researchers achieved a significant breakthrough. Although there is much work to be done before space-based solar power comes to life, these advancements are promising steps toward achieving global climate targets. Besides, the study found that lunar-made solar power satellites could prove to be more cost-effective than their Earth-developed counterparts.