Types of Photovoltaic Systems
There are many different types of photovoltaic systems. Some systems work better than others depending on your needs. Here are the main ones.
These are photovoltaic panels with no battery system. They work when the sun is shining, but if it is cloudy or nightime, they produce no electricity. This type of system is simple and cost effective to set up, and is good for remote locations.
However they aren't suitable for homes where you want power round the clock.
These systems use solar energy as it is created. When the sun isn't shining, power is supplied from the grid. When photovoltaic panels are supplying more energy than you are using, this power can be sold back to the grid. You can literally spin your power meter backwards.
Remote System with Battery Backup
This is popular for remote areas outside the grid. Energy is gathered from the sun and stored in batteries. This way, when there is no sunshine, battery power can be used. Often these systems have additional generator backup to allow for several days of no sunshine.
Grid Tied with Battery Backup
solar energy stored in batteries can be used at nightime. Using net metering, unused solar power can be sold back to the grid. With this system, you will have power even if your neighborhood has lost power.