Is space-based solar power a costly, risky dream, or a realistic way to fight climate change? Sending solar power from space to Earth may ultimately require transmitting gigawatts of power, but experts from Space Solar, the European Space Agency and the University of Glasgow say the process could be surprisingly safe and cost-effective.
But if we want to develop that potential, we need to go well beyond demonstration hardware and overcome several engineering challenges.
Space Solar Power Design
Beaming solar energy from space is nothing new — communications satellites have been beaming solar-generated microwave signals to Earth since the 1960s — but transmitting useful amounts of power is another problem entirely.
“idea [has] Nicole Caplin, a deep space exploration scientist at the European Space Agency (ESA), said: Physics World Podcast“The original concept was definitely science fiction. It’s kind of rooted in science fiction, but interest in it has tended to wax and wane since then.”
Researchers are looking at several designs for space-based solar power, said Matteo Cerriotti, a senior lecturer in space systems engineering at the University of Glasgow. Written for The Conversation Many designs have been proposed.
According to Sanjay Vijendran, head of the Solaris initiative at ESA, the Solaris initiative is looking at two possible technologies: beaming microwaves from a station in geostationary orbit to a receiver on Earth, or using giant mirrors in low orbit to reflect sunlight onto solar farms. He believes both solutions are potentially valuable. Microwave technology has attracted widespread interest and was the main focus of the interview. Higher frequency radio waves can also be used, but this technology has great potential.
“We could provide clean power from space 24/7,” Vijendran says, because microwave frequencies mean the power can be transmitted regardless of weather.
“A 1 gigawatt plant in space would rival the top five solar power plants on Earth. A 1 gigawatt plant could power about 875,000 homes for a year,” said Andrew Gleister, host of the Physics World podcast.
But we’re not ready to deploy anything like this just yet: “It’s going to be a big technical challenge,” Caplin said. There are a number of physical hurdles to building a solar power plant in space.
Using microwave technology, the solar arrays of an orbital power station to generate one gigawatt of power would need to be more than one square kilometre in size, he said. Nature article An article by senior reporter Elizabeth Gibney. “It’s more than 100 times the size of the International Space Station, which took 10 years to build.” The orbital facility will be unmanned, so robotic assembly will also be required.
The solar cells must be resistant to space radiation and space debris. They also need to be highly efficient and lightweight, with a power-to-weight ratio 50 times greater than that of typical silicon solar cells, Gibney wrote. Keeping the cost of these cells down is another factor engineers must consider. Reducing losses during power transmission is another challenge, Gibney wrote. Energy conversion rates need to improve to 10 to 15 percent, according to ESA. This will require technological advances.
Space Solar is working on a satellite design called CASSIOPeiA, and is reporting in Physics World explain It is described as being “like a spiral staircase, with the solar panels as the ‘steps’ and the microwave transmitters (rod-shaped dipoles) as the ‘kicks.'” It has a spiral shape with no moving parts.
“Our systems are made up of hundreds of thousands of identical, dinner-plate-sized power modules, each containing photovoltaic cells that convert the sun’s energy into direct current electricity,” said Sam Adlen, CEO of Space Solar.
“That DC power drives electronic devices and transmits power to the Earth through dipole antennas. The power that rises in space is [microwaves] It is then radiated to Earth in a coherent beam, received by a rectifying antenna, and converted back into electricity and fed into the power grid.”
Adlen said robotics technology for space applications, such as in-orbit assembly, is advancing rapidly.
Another design, SPS-ALPHA, has a large solar concentrator structure containing many heliostats, small modular reflectors that can be moved individually, Ceriotti wrote. concentration The sunlight is directed at separate power generating modules, which then transmit it back to Earth by other modules.
