A correctly sized and deployed solar power system can perform without interruption, and with little maintenance for many years.
"Off-grid" systems , which do not tie into the power grid, run on a combination of solar panels, batteries and often a backup generator running on gasoline, diesel or Gas.
Off-grid systems are expensive to own and operate, mostly due to the cost of batteries. However with clever System sizing and with the incorporation of a generator costs can be significantly reduced. Off-grid systems gives you true energy independence.