Another common problem, particularly in more rural areas. Power cuts can cause problems and at best mean you can't work while the power is out. At worst you can experience data corruption to your file server.
Protecting yourself against this eventuality is both simple and low cost. A UPS (Uninterruptible Power Supply) will keep your fileserver safe and allow an orderly shutdown before the power is cut.
Typically the UPS will keep the server up for about 15 minutes and will automatically shutdown your server if the power is not restored within this time. You can of course choose to have a larger UPS for more time and even keep your router and phone system alive to allow at least some measure of working while the power is out.