There may not be a "dark side" of the moon, but if and where it is dark, it is dark – and this will stay that way for two weeks. If we want to have colonists up there, they have to stay warm and, among other things, stop the light for the long moonlit night. It turned out that moonshine bricks could be part of the solution.
Of course, they will use the available solar power during the lunar day and you might think that they could only charge a few batteries to keep them up all night. But batteries are big and heavy – not what you want to take for a trip to the moon.
How else could lunar colonies store energy? The European Space Agency has worked with Azimut Space to find out if a kind of impromptu geothermal solution can be realized. And thanks to the samples we got from the Apollo missions, we're pretty familiar with the stuff. Therefore, the team simulated some with terrestrial materials to find out how to handle them.
"In this study, we used earth rocks with similar properties as lunar rocks that were crushed into powder until the particles were the size of the particles in the air equivalent to lunar regolith," said Aidan Cowley of ESA, who oversaw the project.
The faux regolith was pressed into bricks, which were then wired and heated with electricity that could be drawn from solar cells on the lunar surface. The brick was then imitated in a lunar environment ̵
"The use of Moon Regolith to store heat on the Moon would provide us with a wealth of readily available material, meaning that astronauts do not have to take much of the earth with them" said Luca Celotti of Azimut.
The ESA report merely states that the process was "working well", which is not particularly meaningful. I contacted Azimuth for more information. However, it would seem that if the method worked poorly, we would not hear about it at all.
There are a lot of fundamental challenges in creating a massive, raw battery of moondust, but if it works only marginally, it can become an important part of the energy and heat storage that every lunar colony would need to use.