Solar cells made of moon dust could power future space exploration

By Stephen Beech

Solar cells made of moon dust could power future space exploration, suggests a new study.

The same dirt that clings to astronauts’ boots may one day keep their lights on, say scientists.

German researchers have created solar cells made out of simulated moon dust.

The team explained that the cells convert sunlight into energy efficiently, withstand radiation damage, and mitigate the need for transporting heavy materials into space - offering a potential solution to one of space exploration's biggest challenges: reliable energy sources.

The cells would slash a spacecraft’s launch mass and transport costs, according to a study published in the journal Device.

Lead researcher Dr. Felix Lang, of the University of Potsdam, said: “The solar cells used in space now are amazing, reaching efficiencies of 30% to even 40%, but that efficiency comes with a price.

“They are very expensive and are relatively heavy because they use glass or a thick foil as cover.

"It’s hard to justify lifting all these cells into space.”

Instead of having to take solar cells from Earth, Dr. Lang’s team is looking at materials readily available on the moon.

They aim to replace Earth-made glass with glass crafted from lunar regolith - the moon’s loose, rocky surface debris.

The team says that change alone could cut a spacecraft’s launch mass by 99.4%, slash 99% of transport costs, and make long-term lunar settlements far more feasible.

To test the idea, the research team melted a substance designed to simulate moon dust into moonglass and used it to build a new kind of solar cell.

The team crafted the cells by pairing moonglass with perovskite - a class of crystals that are cheaper, easier to make, and very efficient in turning sunlight into electricity.

For every gram of material sent to space, the new panels produced up to 100 times more energy than traditional solar panels.

Dr. Lang said: “If you cut the weight by 99%, you don’t need ultra-efficient 30% solar cells, you just make more of them on the moon.

"Plus, our cells are more stable against radiation, while the others would degrade over time.”

When the team zapped the solar cells with space-grade radiation, the moonglass versions outperformed the Earth-made ones.

Standard glass slowly browns in space, blocking sunlight and reducing efficiency.

But the researchers explained that moonglass has a natural brown tint from impurities in the Moon dust, stabilizing the glass, preventing it from further darkening, and making the cells more resistant to radiation.

Dr. Lang's team found that making moonglass was "surprisingly simple".

They said it doesn't require complex purification - and concentrated sunlight alone can provide the extreme temperatures needed to melt lunar regolith into glass.

By tweaking the thickness of the moonglass and fine-tuning the solar cell’s composition, the team managed to achieve 10% efficiency.

With clearer moonglass that lets in more light, they believe they can reach 23%.

But Dr. Lang says the moon poses challenges that Earth doesn’t.

He said lower gravity could change how moonglass forms.

The solvents currently used to process perovskite won’t work in the Moon’s vacuum.

And wild temperature swings could threaten the materials’ stability.

To find out if their moon dust solar cells are truly viable, the team hopes to launch a small-scale experiment to the moon to test them out in real lunar conditions.

Dr. Lang added: "From extracting water for fuel to building houses with lunar bricks, scientists have been finding ways to use moon dust.

"Now, we can turn it into solar cells too, possibly providing the energy a future moon city will need."