How solar farms in space might beam electricity to Earth?

A scheme to gather solar energy from space and use microwaves to broadcast it to Earth seems too good to be true.
But according to Martin Soltau, co-chairman of the Space Energy Initiative (SEI), a partnership of business and academia, it might occur as soon as 2035.
A constellation of extremely large satellites will be launched into a high Earth orbit as part of the Cassiopeia project, which is being worked on by SEI.
The satellites would capture solar energy once they were in place and send it back to Earth.
According to him, the potential is practically limitless.

According to him, in 2050, it “could theoretically supply all of the world’s energy.”
“The Sun has a huge energy reserve, and there is enough space in orbit for satellites powered by solar energy. More energy is received annually in a small area of geostationary Earth orbit than is anticipated to be used by all of humanity in 2050 “Says Mr. Soltau.

Following an engineering study undertaken by firm Frazer-Nash that determined the technology was practicable, the UK government approved £3 million in financing for space-based solar power (SBSP) projects earlier this year.
SEI wants to take home a sizable portion of that cash.
The company’s satellites would be built from millions of tiny, identical modules produced in factories on Earth, assembled in space by self-sufficient robots, and maintained by such robots.
The satellites would transform the solar energy they receive into high frequency radio waves and send those waves to a rectifying antenna on Earth, where the radio waves would be transformed into electricity.

When it comes to power output, each satellite is comparable to a nuclear power plant at roughly 2GW per satellite.
Sunlight is filtered by the atmosphere here on Earth, but it is unaltered in space because it comes from the sun straight.
Therefore, a solar panel mounted in space may gather much more energy than an equivalently sized one on Earth.
Other places are developing similar projects.

In the US, for instance, the Space Solar Power Incremental Demonstrations and Research project of the Air Force Research Laboratory (AFRL) is focusing on some of the crucial technologies required for such a system (SSPIDR).
In addition to lowering the significant temperature changes on spacecraft components, they include developing designs for deployable structures, increasing solar cell efficiency, solar-to-radio frequency conversion, and beam shaping.
The team successfully tested new parts for a so-called sandwich tile, which is used to transform solar energy into radio waves, in the latter part of last year.
Although the microwave beams may seem dangerous, they have been tested on Earth and shown to be efficient and safe for both people and wildlife.

According to Mr. Soltau, the beam is microwave-based, making it similar to the constant wi-fi we use. It also has a modest intensity—roughly one-fourth that of the noon Sun.
“This is just approximately 240W per square metre, compared to the 1,000W per square metre you would receive if you were in the desert on the equator. In that sense, it is safe by nature.”

There are still possible issues, despite the fact that many of the main obstacles have already been overcome.
Dr. Jovana Radulovic, a thermodynamics lecturer at the University of Portsmouth who specialises in renewable energy systems, says, “My personal perspective on this is that we want to think the technology is there, but it’s not yet ready for us to begin on a project of this magnitude.”
She raises the argument that deploying several solar panels into space would be costly and produce a lot of carbon dioxide considering that any project would require hundreds of launches.

But there is reason to be upbeat. According to a University of Strathclyde environmental estimate of the Cassiopeia project, the whole carbon footprint, including launch, might be as little as half that of terrestrial solar, at roughly 24g of CO2 per kilowatt-hour.

According to Mr. Soltau, the economic case is steadily getting better.
According to him, the cost of launch has decreased by 90% and is still decreasing, which has completely changed the economics.
“Second, there have been some significant improvements in the architecture of solar-powered satellites, resulting in a much more modular construction that increases durability and lowers production costs. Thirdly, robots and autonomous systems have made significant strides.”

SEI is seeking to entice private investment for some of the technologies linked with the UK government’s meagre support. Dr. Radulovic cautions that the suggested timescale might be too ambitious.
There is, she asserts, “no reason why we couldn’t have the system up and running as smaller pilot projects in the near future,” with sufficient investment and concentrated work.
However, a large-scale project — we’re talking about kilometres of solar arrays — would require much more time.