Pyrite panels could help power future Moon bases

Pyrite could help provide energy independence for future Moon settlements, ERR reported. Researchers at Tallinn University of Technology are developing flexible solar panels that could eventually be made from raw materials found on the Moon.

Humanity is planning to return to the Moon and establish permanent bases, which would require large and continuous supplies of energy. Conventional silicon panels, which have been used on rooftops for decades and are increasingly installed in fields beside roads, would be poorly suited to the harsh space environment. Silicon plates are heavy and brittle, while transporting enough of them to the Moon would require excessive amounts of rocket fuel and money.

The researchers see a possible solution in pyrite, a widespread mineral commonly known as fool’s gold. “Many of us have probably come across a golden-shining mineral while walking on the beach that initially appears to be gold but, on closer inspection, turns out to be fool’s gold,” Taavi Raadik, a senior researcher at Tallinn University of Technology’s Institute of Materials and Environmental Technology, said on the programme “Attention! This Is Science.”

“At Tallinn University of Technology, we are studying how this fool’s gold could be turned into real gold when used in solar cells,” Raadik said.

Unlike rigid silicon, the Estonian researchers’ solution uses monograin technology. The research team synthesises pyrite microcrystals and spreads them across flexible epoxy. The polymer base gives the finished product elasticity, turning the panel into a thin membrane that is partly transparent in light.

The new material could be attached to curved surfaces, including buses on Earth or future lunar rovers.

“Monograin means that the crystals we synthesise are placed on the membrane side by side in a single layer,” researcher Katriin Reedo explained. “Each small crystal is an independent solar panel, and there are a great many of them. In principle, it is like electricity-producing sandpaper.”

Pyrite found in nature cannot be used to capture solar energy directly because it contains too many impurities. The scientists must grow suitable crystals in a laboratory from completely pure starting materials.

The team first weighs the components into a special ampoule. To create the right environment for crystal growth, it adds molten potassium iodide salt.

“Once the starting materials have been weighed into the ampoule, the air is pumped out and the ampoule is sealed,” doctoral student and junior researcher Mia Maria Meldorf said, describing the laboratory process.

The ampoules then spend two weeks in a high-temperature furnace. “After synthesis, the finished pyrite microcrystals are mixed with the molten salt and have solidified. To remove it, we wash the microcrystals and sieve them to obtain the right fraction,” Meldorf said.

Before the technology can be sent into space, the researchers must solve a serious materials science problem. Each solar panel consists of many layers that must work together without failure.