Energy storage

The availability of energy is one of the vital requirements for a settlement on Mars. Solar power and wind turbines are subject to changing weather conditions, especially during the martian night, which makes energy storage necessary.

Nuclear power has been considered as the preferred energy source for most plans for medium- to long-term human expeditions to Mars. However, this is scarcely an option for an autonomous colony due to the vast effort of the nuclear enrichment process.

Compressed-air

Compressed-air storage is a recently upcoming technology to store large amounts of energy. Natural Martian caves can be used as a pressure accumulator.

Chemical

Electrical energy can be stored in a flow battery. The capacity depends on the size of the tanks and can be easily extended.

Another way to store excess energy is a sophisticated management of production processes. Energy consuming production processes can be carried out during periods of available energy (e.g. daylight), such as the production of liquid hydrocarbons out of atmospheric carbon dioxide. At night the exothermic production processes are carried out, such as some recycling processes.

Other

Most conventional schemes (e.g. batteries and flywheels) are practical on a small scale, but do not scale up very easily.