Harnessing solar power from space has been a clean energy dream for decades. Space-Based Solar Power remains a captivating prospect, and the technology can provide Earth with clean and reliable energy 24 hours a day.
Earth’s atmosphere, with the day and night cycle and clouds, significantly reduces the average availability of sunlight. However, collecting sunlight in space would be more efficient than doing so on the ground. A step towards this with space-based solar power (in short SBSP).
How does SPSP work? The idea is quite simple: it works around collecting solar energy in space and beaming it back to Earth. It would involve having giant solar farm satellites far away from Earth so that they receive sunlight 24 hours a day. In turn, the power-generating satellites would beam back the collected energy down to the Earth. They could use low-intensity radio waves, where the energy could be sent to strategically placed ground stations connected to the grid or major power users.
In this context, a major milestone was announced recently when the research team at Caltech said that a prototype launched into space was able to beam a small amount of power to Earth. The technology is still at a nascent stage, and other researchers are working around it to make similar progress to reach their climate goals.
Caltech’s research team could overcome the tricky challenge of safely sending electricity zooming from space down to Earth through SBSP. A SpaceX rocket launched a spacecraft into space in January, which carried the prototype built by Caltech. The prototype included solar cells and an array of transmitters that can beam energy to various locations.
After launch, the prototype could beam some power back to Earth in a few months. It could send microwaves to receiver arrays that were a foot away from the transmitter. Further, the receiver arrays could convert the microwaves back to direct current (DC) electricity and light up a couple of LEDs.
In a press announcement, Ali Hajimiri, a professor of electrical and medical engineering who led the Caltech research team, stated that no one had ever demonstrated wireless energy transfer in space, even with expensive rigid structures.
Space-based stations can generate electricity around the clock, making them a sustainable and appealing power source. Today, the world needs plenty of renewable energy to help meet climate goals set in the Paris Agreement; greenhouse gas emissions need to reach net zero.