Solar energy generated in space could become a reality – 01/30/2024 – Market

The young researchers gathered on the roof of the Caltech (California Institute of Technology) engineering laboratory in Pasadena, on a pleasant evening in May 2023, had no intention of making history.

After a long day of assembling equipment to test a solar-powered satellite, the professor heading the project told them to get something to eat and go back.

“It was almost 10 p.m., and we said, ‘Let’s try it. Let’s do a test,'” says Ali Hajimiri, a professor of electrical engineering at Caltech. “At first we thought we weren’t detecting a signal. Then it started to appear and get stronger.”

The team was excited. For the first time, a detectable amount of solar energy had been transmitted wirelessly from space to Earth. It didn’t matter that it was insufficient to light a lamp. For the growing community of space solar advocates, it was proof that it was technically possible to provide power from space to an electricity-hungry planet.

“The sun is the closest thing we have to an infinite energy source,” says Paul Jaffe, an electronics engineer at the U.S. Naval Research Laboratory who has studied space-based solar power for 16 years.

“We can create a global network capable of providing power to potentially anywhere on Earth. Space solar technology could do for power what GPS did for navigation.”

Space solar energy was first discussed by science fiction writer Isaac Asimov in his 1941 short story “Reason.” [do livro “Eu, Robô”]. In reality, however, it has long been dismissed as too expensive and too technologically challenging to be commercially viable.

As the sense of urgency in the face of climate change grows and the economy of space evolves, however, governments around the world are reconsidering its potential. Researchers in China, the US, the UK, Japan and Europe are studying its feasibility, with the idea of ​​possibly launching experiments into space before the end of the decade.

China’s ZhuRi program — translated as “chasing the sun” — has plans to put a pilot plant into orbit generating 20 megawatts of power by 2035.

In the UK, a group of entrepreneurs funding the government-backed startup Space Solar is even more ambitious. Its goal is to build a gigawatt-scale power plant in space by the same date, growing to a fleet of plants providing 30 gigawatts to the power grid by 2040.

Although Caltech’s experiments were funded by billionaire philanthropist Donald Bren rather than the government, the U.S. Air Force Research Laboratory is planning a low-Earth orbit power transmission demonstrator in 2025.

Energy combination

Space solar energy, for now, is the domain of researchers. But as environmental pressures mount, some investors are starting to take this technology more seriously.

The UK government is negotiating with Saudi Arabia to invest in space solar energy in collaboration with Space Solar, which is in the process of raising funds.

But without buy-in from the energy sectors and distribution companies to end users, space-based solar will remain a pipe dream.

“This should be conducted as an energy project that has a large space element,” says Sanjay Vijendran, who leads the European Space Agency’s Solaris project. “We are trying to [o setor de energia] take control as quickly as possible.”

That’s why the European Space Agency’s study includes companies like Italy’s Enel and France’s Engie. In the United Kingdom, EDF is studying the technology’s potential for the country’s innovation agency. But in general, energy companies are still in wait-and-see mode.

“There are still some significant question marks around this – like: is it really possible to build, operate and launch this system?” says David Ferguson, head of net zero innovation at EDF. “There is a lot that still needs to be proven from a technical point of view.”

As with renewable energy and the need for extra storage, there are also hidden costs in a space solar power system.

EDF researchers estimate that “space weather” – factors such as solar flares, geomagnetic storms and radiation – could degrade satellites more quickly than expected. This would add around £2 to £7 to the cost per megawatt hour.

“We think there is a productivity loss of around 20% over the lifetime of the system due to space weather,” says Ben Cayless, renewable energy engineer at EDF.

However, EDF, like Enel and Engie, is not prepared to ignore the potential of a new clean energy source. “Our strategy will not change based on this work or in the short term,” says Cayless.

“But most companies are like us. We are evaluating this and keeping our options open.”

Energy potential could be greater than that of nuclear fusion

Many advocates of space-based solar power (SBSP) believe the technology has greater potential than nuclear fusion to help the world reach its net-zero CO2 goals.

“All physics [da energia solar baseada no espaço] has been demonstrated, tested and verified,” says John Mankins, a former NASA physicist whose work at SBSP over more than 25 years earned him the nickname “godfather of space solar power.”

Although American scientists said they achieved a net energy gain in a fusion reaction last year, the process “is still a few years away from demonstrating that the system would generate more energy than we needed to put into it,” says Mankins.

With enough investment, adds Vijendran of the Solaris project, “space solar could be available sooner than fusion.”

Solar energy is captured using solar panels attached to a satellite that flies thousands of kilometers above the Earth’s surface, under constant sunlight. This energy is then converted into microwaves, which are transmitted through the atmosphere to a receiving antenna, where they are converted back into electricity to be distributed across the grid.

A single satellite could potentially provide up to 2 GW of carbon-free energy, enough to power a city of 2 million people, 24 hours a day, seven days a week.

Oxfordshire-based Space Solar estimates that a solar-generating satellite would produce energy at a cost of just $34 per megawatt-hour by 2040 to break even over its lifetime, versus US$43 (R$213) per MWh for a large onshore solar farm, US$53 (R$265) per MWh for offshore wind and US$125 (R$620) per MWh for nuclear.

“The economy works really well, and this could really be transformative,” says Martin Soltau, who led the UK study by consultants Frazer-Nash, before founding and becoming deputy chief executive of Space Solar.

Many believe, however, that space-based solar energy still belongs to the realm of science fiction. SpaceX founder Elon Musk once called the concept “the dumbest idea ever.”

Their argument was that the large energy losses during the conversion of sunlight into electricity made space solar energy much less efficient and uncompetitive with solar farms on Earth.

Harry Atwater, one of three Caltech professors leading the university’s Space Solar Energy Project and an expert on photovoltaics, disagrees.

“Going from sunlight in space to electricity on Earth would be about 5% efficient,” he says – meaning up to 95% of the energy would be lost. But the amount of sunlight in space in a 24-hour period “is eight times greater than on Earth.”

“It would be similar to having a cell [solar] with 40% efficiency on Earth. We don’t have any like that. People now want to get to 30% – maybe.”