There are three basic types of solar power systems: grid-tied solar power systems, off-grid solar power systems, and backup power systems.

Grid-tied Solar Power System

Grid-tied solar power system is the most common type of solar power system and the most cost-effective solar power system.It is a solar power system connected to the home and traditional electric utility grids. This type of solar power system does not include any storage batteries.

Grid-tied solar power systems work by sending energy generated by solar panels into the grid, where it is stored for later use. Under a net metering agreement, system owners get electricity from anything they generate, and they can use that energy whenever they want.

Grid-tied systems are less expensive and use less equipment than other types of rooftop solar. Solar panels have a 20-25 year warranty. And the grid-tied system is simple and has no downtime. These are the advantages of grid-connected systems.
The downside of grid-tied systems is that they are still vulnerable to power outages.

Off-grid solar power systems

An off-grid solar power system is a completely self-contained solar power system with energy storage that is not connected to the main utility grid. Off-grid solar systems are best suited for delivering power to remote areas that don't have access to utility lines.
The advantage of an off-grid solar power system is that you are not dependent on the utility company. You are not bound by the utility company's terms and policies. There are no electricity bills and no power outages.
The disadvantage of the off-grid solar power generation system is that the initial cost is high, the components of the off-grid system are relatively expensive, and sufficient batteries need to be prepared for weather without the sun. Another is energy efficiency, which requires off-peak electricity consumption to reduce energy storage costs.

Backup power systems

If you live off the grid but want to protect against blackouts, your best bet is a battery backup system.
The backup power system is connected to the grid and operates like a normal grid-tied system in day-to-day work. However, they also have a backup battery pack that takes over in the event of a power outage.
When the grid loses power, your inverter automatically disconnects from the grid and utilizes the energy stored in the battery pack, which will keep your equipment running while the grid loses power.
A backup solar power system has an energy storage system that if your solar power system produces excess energy, it can be stored in batteries. When there is no sunlight or a power outage, you can still power your home.
The downside of back-up solar systems is the higher system cost because the batteries need to be replaced periodically. This type of solar power system is complex, so you may need a solar installer with a higher level of expertise to design and install it.