Solar cells could be manufactured remotely on the moon

Researchers from the University of Houston’s Texas Center for Superconductivity and Advanced Materials (TcSAM) have been studying the possibility of making solar cells from simulated lunar soil. The soil has been copied from the 800lb of moon rock brought to Earth by NASA throughout its moon exploration programme, TcSAM Senior Research Scientist Charles Horton told edie.

Although there are currently no plans to return man to the moon, “it’s going to happen sooner or later”, says Horton, which means it will pay to be prepared.

One of the biggest barriers to the space programme is the high cost involved. Providing the ability to make solar cells remotely from materials on the moon will reduce the weight of materials being transported, and therefore the cost, says Horton.

The manufacture process will involve an autonomous lunar rover moving across the moon’s surface, melting the regolith into a very thin film of glass. Such thermal film deposition is best done in a vacuum, which means that the moon’s lack of an atmosphere provides suitable conditions.

One drawback of the technology is that the efficiency of the solar cells is extremely low – in the order of only a few percent, says Horton. However, as the size of the solar cells is restricted only by the size of the moon, low efficiency can be compensated for by producing giant cells. If it works out the way the scientists expect it to, they should be able to produce sufficient solar cells for 1MW within two to three years, said Horton.

Earlier this year, edie reported the claims of an industrial physicist from the University of Houston, Dr David Criswell, that – technically – all of the Earth’s power could be supplied by solar cells on the moon (see related story).

The University of Houston scientists presented their research to the World Space Congress 2002, held in Houston from 10 to 19 October.

The scientists also gave a presentation on a high-efficiency solar cell technology patented by one of their number, Alex Freundlich, Research Professor of Physics at the University. Typically, space solar cells used on orbiting satellites today have an efficiency in the order of 28%, says Horton. Freundlich’s technology uses a thin layer of nano-engineered material not only to increase the efficiency of absorption of solar energy, but also to increase the range of the solar spectrum that is absorbed.