Residential solar power systems can be stand-alone off-the-grid solar systems, or they can be integrated to work together with utility service electrical power.
Stand-alone residential solar power systems aim to provide your home with self-sufficiency, and once installed and running the solar power you make is all the power you have to run everything with.
An integrated mains/solar power system makes electricity while the sun shines and can charge your storage batteries at home. Some integrated solar systems will even pump any excess electricity back into the electricity grid, for which your electric power company will reduce your bills accordingly.
And at night time if your battery power isn't enough, and when no sun is shining, these sophisticated residential solar power systems can switch back to mains electricity and use that like any other household.
The advantages are that you have the best of both worlds. You enjoy free electricity from the sun when its available and when there's enough in your storage batteries. But if your solar system can't quite cope, the mains power is switched on automatically and life continues uninterrupted.
There's no need to run a portable generator or anything like that... unless of course you want an extra layer of protection when things go wrong.
Residential solar power systems can be as simple or as complex as your needs and budget will allow. Some people need nothing more than a 60 watt panel and a 12 volt car battery; that's enough to light a trailer of a small cabin. While others will opt for enough solar electricity to have power to spare. And in that case, it is possible to have your surplus power fed back into the electricity grid - so you actually get paid for it!