Even though having a mini-nuclear reactor nearby is not a bad idea, settlers upon Mars may prefer an option that relies less upon the splitting of the atom and more upon the rays of the Sun.
Scientists in Spain have figured out a way for solar power stations to generate energy after sun set when rays from the Sol star are no where to be found.
Gemasolar, the concentrated solar power plant located in Fuentes de Andalucía (Seville), a property of Torresol Energy (a joint venture between Masdar – Abu Dhabi’s future energy and clean technology company and SENER – the leading Spanish engineering and construction company) has supplied its first uninterrupted day of electricity to the network.
This has been made possible by its innovative technique of storing solar energy in molten salt, a cutting-edge thermal-transfer technology developed by SENER. This system is capable of fifteen hours of electricity production without solar radiation which overcomes fluctuations in the energy supply. [...]
The salt storage system allows the plant to stretch its electrical production hours to beyond sunset, regardless of the cloud cover. Thus, Gemasolar, with its 19.9 MW steam turbine, is able to supply electricity to a population of 25,000 households.
Eventually the plant will be able to supply 24hrs of uninterrupted production per day on most summer days, providing a higher annual capacity factor than most baseload plants such as nuclear power plants. (Torresol Energy
Although Martian settlers will probably need a mini-nuclear plant as a backup energy source (as Martian hurricanes have a habit of blocking out the Sun worldwide), relying upon a solar-thermal hybrid could enable colonies to thrive upon Mars without having to rely upon infrequent shipments of nuclear plants from Earth.
This technology would also benefit asteroid colonies as well, as it would enable settlements within the inner solar system to become less dependent upon Earth (or even Mars) for resources.
Note: Since sunlight intensity tapers off beyond Mars, solar power (of any kind) would be useless for out posts established upon Jupiter’s mega moons (Callisto and Ganymede), who would need to rely upon nuclear energy to avoid freezing to death.