Press article in Estonian Postimees Teadus on February 20, 2025
https://teadus.postimees.ee/8196384/eesti-teadlased-sillutavad-teed-kuul-paikeseenergia-tootmiseks
English translation:
TalTech senior researcher Taavi Raadik is working on a future where people
will be permanently present on the Moon and solar panels will have to be made from local materials.
Transporting them from Earth would be too expensive.
Photo:TalTech
- In space, solar energy is 30% more powerful than on Earth and available all the time.
- The goal is to build space solar stations that would send electricity to Earth.
- The solar panels developed by TalTech scientists are lightweight, flexible, and suitable for space.
What could the future of solar energy look like in space, for example on the Moon? Senior researcher Taavi Raadik , whose team at the Solar Energy Materials Research Laboratory is working to take solar energy to new heights, literally – in space, is looking for an answer to this question on TalTech’s business and science portal Trialoog.
The team’s ambitious activities are based on close collaboration with the European Space Agency (ESA) and the Swiss company Astrostrom, who share a common vision that would make the collection and transfer of solar energy in space a reality, thereby supporting both the greening of the Earth and future space missions.
Raadik began his scientific career as a physics student, and his interest in solar energy deepened during his undergraduate studies.
He turned his focus to space in 2015, when Estonia became a member of the European Space Agency: “An ESA representative contacted us and the first joint project began, during which we investigated the suitability of a monocrystalline solar cell developed in our laboratory for the space environment. I had just defended my doctoral thesis and was open to new challenges, so the offer of cooperation came at exactly the perfect time.”
Cat’s gold for energy
The monocrystalline monograin layer technology being developed at TalTech’s Solar Energy Materials Research Laboratory is unique. It uses tiny microcrystals, two-thirds thinner than a human hair, that work as independent solar cells.
The amount of energy produced by a single microcrystal is extremely small, but since there are millions of crystals in a module, they have a considerable impact.
“This type of solar cell is lightweight, flexible and can be produced cost-effectively. In addition, the technology is more environmentally friendly than traditional silicon-based solar cells and is also suitable for space conditions.”
Domestic cat’s gold is also found on the Moon, which means that solar panels could be produced there too.
The picture shows pyrite crystals grown in a molten salt environment, which will produce electricity.
Photo:Taavi Raadik
Raadik said that the main focus of the monocrystalline solar cells being developed at TalTech is on terrestrial applications. Under the leadership of Professor Marit Kauk-Kuusik, building and product-integrated solutions and solar cells for indoor use are being developed. However, Raadik’s team is exploring the cosmic potential of this technology.
“What makes this technology special in the context of space is that the microcrystals used in solar cells are made of pyrite, also known as cat’s gold. These microcrystals can also be made from elements and compounds found on the surface of the moon, for example,” explained Raadik.
According to Raadik, the cosmic race is in full swing: “Regardless of the destination, we have to somehow survive in this hostile space environment, and energy is the basis of everything.”
So far, humans have only been on the Moon for a short time.
Since there are plans to go to the Moon for an extended period of time in the future, it is necessary to establish a permanent base where astronauts can live and work safely.
“The moon is not very human-friendly – the temperature varies from a decent Finnish sauna to the coldest Antarctic night. To survive, we need different technologies that would help us produce oxygen for breathing, as well as build shelter.”
But where can we get the energy to keep all the systems running? This is where the Sun comes to the rescue.
“Crazy ideas often lead the way. Our work could create the foundation upon which the next generation of energy solutions will be built – both on Earth and in deep space.”
“In space, solar energy is about 30% more intense than on Earth, which is why productivity is significantly higher. In the long term, we cannot avoid valorizing local resources, because a permanent supply chain between the Earth and the Moon would be too complicated and we will have to learn to live independently on the Moon, so-called. off the Earth ,” explained Raadik.
If the Moon were to be able to produce solar cells using locally available resources, one of the biggest bottlenecks in cosmic energy could be solved – the expensive transportation of solar cells.
Science fiction today, reality the day after tomorrow
Astrostrom has a vision to build space solar power plants on the Moon using local resources and place them in geostationary orbit.
“There they can collect energy around the clock and send it as microwaves to quench our energy hunger either to Earth or to the Moon, where the long night lasts for 2 weeks,” adds the scientist. The electricity produced in this way is stable and environmentally friendly.
The role of TalTech scientists in this collaboration is to develop technology that would allow solar cells to be produced locally on the Moon.
According to Raadik, success stories are born as a team.
Pictured are two members of Raadik’s team:
Doctoral students Katriin Kristmann and Marc Vincent Heemskerk.
Photo:TalTech
According to Raadik, the first serious space-based solar power plants could see the light of day in about ten years or even sooner: “Work is underway around the world for this. For example, UK-based Space Solar has joined forces with the Icelandic company Reykjavik Energy. Together, they promise to build and launch the first commercial space-based solar power plant into orbit by 2030, which would provide energy to up to three thousand Icelandic homes.”
However, production on the lunar surface may take longer – Raadik predicts that this could happen in 15–20 years, depending on the speed of technological development and investments.
“What was once considered the realm of science fiction is becoming reality. Our research contribution forms a very important piece of the larger puzzle,” said Raadik.
From the Seventh Continent to Mars and Beyond
Speaking about the importance of lunar exploration, Raadik referred to the ESA director’s idea that it could become Earth’s “seventh continent.” Exploring the Moon as a potential energy source paves the way for the next important milestone – the conquest of Mars.
The work of Raadik and his team provides an excellent example of how academic and industrial collaboration leads to innovation and helps us move towards a greener and more sustainable future.
“Crazy ideas often lead to progress. Our work can create the foundation upon which the next generation of energy solutions will be built – both on Earth and in deep space,” said Raadik.
According to Raadik, no success story is based on a single person; it requires a team whose members share the vision of a “cosmically crazy” idea.
“I also want to pay a deep tribute to my supervisors, Prof. Jüri Krustok and Prof. Maarja Grossberg-Kuus. They once guided me into this endlessly exciting world of science. Without them, we would not be conquering space today.”
With state and political support, the Estonian space sector has developed significantly and several companies have reached a considerable level. However, he emphasized that it is more difficult for universities to find funding, as their focus is on basic research and projects with low technological readiness.
In his opinion, the Estonian state should contribute more to space-related research, as universities are able to address problems in depth and find solutions that may develop into important applications in the future.
ESA highlights the perseverance of TalTech scientists
Dr. Advenit Makaya, an engineer for innovative manufacturing technologies at the European Space Agency, said that the collaboration with TalTech began with Taavi Raadik’s previous research projects, which have now led to a dialogue and an innovative research topic – how to make solar panels from pyrite, or cat’s gold, found on the surface of the Moon.
Makaya recognizes the perseverance and innovative spirit of TalTech researchers: “When the results do not meet expectations, instead of giving up, they look for alternative solutions and continue working towards the goal. TalTech researchers are motivated, proactive and of a very high standard – their work proves that a small country like Estonia can have a big impact.”
According to Makaya, TalTech is a good example of how original ideas and focused work can lead to technological leadership in a certain field: “Estonia has the potential to play an important role in space exploration, as it focuses on narrow and innovative technologies that allow for building larger forms of cooperation in the international space ecosystem.”
Image: Astrostrom’s Greater Earth Lunar Power Station
Makaya estimates the project’s impact on the future of space energy to be very large, as the production of solar panels from lunar resources could offer a very sustainable solution in the field of space energy.
This, he says, would reduce dependence on Earth’s resources and create opportunities for longer-term space missions: “If we decide to stay on the Moon for a longer period of time, local resources will become essential.”
TalTech and Astrostrom: A solution that reaches for the Moon
The cooperation between Astrostrom and TalTech began as part of a European Space Agency (ESA) program, which sought solutions for producing clean energy in space.
Astrostrom founder Arthur Woods said that the monocrystalline layer technology being developed by TalTech researchers attracted his attention because it allows for the production of lightweight and flexible solar panels and reduces dependence on Earth’s resources.
Woods sees collaboration with TalTech and other academic institutions as an important step in developing space energy: “The academic institutions provide a scientific foundation on which companies can build innovation and bring their technologies to market.”
In his opinion, energy produced in space could become crucial in the future in the context of the Earth’s green transition and reduce geopolitical tensions.
