There are basically three types of Solar Electric Systems which are: the Grid Tied Solar Systems, the Grid Tied Solar System with a Battery Back-up or Hybrid Power Generator, and the Off-Grid Solar Power System. There are other types which are mainly deviations or contain additives on these three main types. The home or business owner together with investigated decisions from the Solar Engineer or Contractor can tweak and make changes to the Electric system as they see fit. Lets take a look at these systems and where they can be installed.
1 - Grid Tied Solar System: This is a very common installation you will find in most areas of the US, and other parts of the world. This system is favorable for cities and suburbs or residential areas with close connections to the electric grid. In this system, the PV installation is connected to the grid and a two way meter may be installed to read the flow of electricity to and from the grid. The advantage with this system is that the PV installation may not necessarily be seized to meet all the needs of the residence or business. If demand surpasses supply at any one time especially in peak hours, electricity is simply pulled from the grid to make up. This situation is reversed when the capacity of the installed system is high enough and produces more then needed electricity. The extra electric power is pushed or back-fed into the grid which produces credits the consumer can then use at periods of low production such as at night to offset their power consumption.2 - Grid Tied Solar System with Battery Back-up or Hybrid Power Generator:
This system can be described as the above system but differs in that it has a battery or power generator component. The system best suits areas without a credible power grid. The Solar engineer may design the system to store some of the electricity produced when production exceeds demand, in specially designed 'Deep Cycle Batteries' for use when the grid goes down. The engineer can also incorporate a fuel electric generator in the design dubbed 'hybrid' for the same function.3 - Off-Grid Solar Power System: This system is completely cut off from the traditional grid. It best suits locations such as cabins in the woods, mountains or remote areas of the developing world with no electric grid. This system also incorporates the battery and the power generator in its design. Instead of using a battery or generator as a simple back-up, it is used as a necessary component. The battery is used to save electricity for rainy days - literarily - while a generator is needed when the battery drains out due to continues use and in days with no power production.
As earlier noted, installing any of these systems depends on your location and recommendation by the Solar engineer or professional. It is important to note that in each design, convenience and efficiency will be affected.
