Space Solar is working on the design of a satellite called CASSIOPeiA, which Physics World describes as if it were “a spiral staircase, with the photovoltaic panels as the ‘rungs’ and the microwave transmitters (rod-shaped dipoles) as the ‘risers’”. It is helical in shape and has no moving parts.
“Our system is made up of hundreds of thousands of power modules about the same size as a dinner plate. Each module has the photovoltaic power that converts the sun’s energy into direct current electricity,” said Sam Adlen, CEO of Space Solar.
“That direct current drives electronic components to transmit energy… to Earth from dipole antennas. That energy in space is converted into (microwaves) and sent in a coherent beam to Earth, where it is received by a rectifier antenna, converted back into electricity and sent to the power grid.”
Adlen said robotic technologies for space applications, such as on-orbit assembly, are advancing rapidly.
Ceriotti wrote that SPS-ALPHA, another design, has a large solar collector structure that includes many heliostats, which are small modular reflectors that can be moved individually. concentrate Sunlight is transmitted to separate power generating modules, after which it is transmitted back to Earth by another module.
Space-based security
These plans involve large fluxes of microwave or radio radiation, but space solar power is relatively safe. In the case of microwave radiation from a space solar power facility, “the only known effect of those frequencies on humans or living things is tissue heating,” Vijendran said. “If you were to stand in a beam of that power level, it would be like standing in the evening sun.” Still, Caplin said more research is needed to study the effects of these microwaves on humans, animals, plants, satellites, infrastructure and the ionosphere.
However, getting the public to understand this may still be a challenge. “There is still a public perception issue to resolve and it will take a strong commitment to successfully bring this to market,” Adlen said.
Military attacks using space solar power could also raise concerns. But even if a space solar power plant were hijacked for military reasons, the hardware would limit the beam to a safe intensity so it couldn’t be used to harm people or ecosystems on Earth, Ceriotti said.
In addition to environmental issues, there are other concerns that will need to be addressed before deployment. Interference with communication signals is another potential risk, although Gibney wrote that the beam frequency would not disrupt communication between aircraft. Other physical risks are important to consider.
According to Vijendran, orbiting debris such as meteorites or space junk could impact the station and damage it. If impacts on the solar power plant generate debris, that could also cause problems. In addition, the hardware itself will have to be deorbited when it reaches the end of its useful life. “ESA has a Clean Space Initiative. Anything we send into space, we have to think about the whole life cycle, from cradle to grave,” Caplin said.
Finally, the project would still have an environmental impact. Putting the solar plant hardware into orbit, building it and controlling it would generate pollution and consume a substantial amount of fuel, Ceriotti wrote. Hundreds of launches could be needed.
Launch economy
In addition to their environmental impact, such launches will cost money. Until now, cost has been the main obstacle to building a space solar power plant, Caplin said. “As that landscape is changing and it’s generally becoming cheaper to send things to space, we can put that back on the table. Money talks. We had advice from two independent cost-benefit studies, and both found that this could be feasible.”
The cost of space-based solar power would include manufacturing costs, maintenance costs and launch costs, Ceriotti said.