(Hat tip: IsraGood)
With average tempreatures hovering around -63 degrees Celcius, future Martian colonists are going to have to find innovative ways of staying warm--not to mention power their (hopefully) growing communities.
Since it may be awhile before Earth may allow future Martians to have a nuclear power plant (due to political reasons), residents may have to rely on using "solar steam power" technology to keep the lights on--not to mention biospheres toasty.
Since Mars has plenty of ice water upon (or underneath) its surface, colonists should have no problem building massive solar power steam plants, which could enable cities to be powered inexpensively (decreasing dependence from Earth for fuel).
Even though this technology is promising, future settlers of Mars may want to consider a variety of alternative energy sources, ranging from hydrogen energy to "green" algae, to even turning future trash into power.
If successful, future Martian metropolises may end up being powered by green technology, providing an example to not only Earth, but future colony worlds as well.