You are probably asking yourself "What is solar energy?" Simply put, it is energy from the sun. There are two types of solar energy that capture the energy from the sun and convert is to something physically usable for consumers: thermal and electric. The two primary purposes of solar energy are to provide heat and electricity.
Thermal Energy is the light and heat created by the sun that helps plants grow, lights the sky, and warms the earth. Thermal Energy is typically used for heating domestic water for in-home use and heating pools.
Electric Energy, also known as Photovoltaics (PV), uses the energy from the sun to produce electricity through the use of solar cells and modules. There are three main system types: stand-alone, grid-tied, and back-up.
Grid-tied systems, the most common type of PV system in urban and suburban areas, are connected to the utility grid but system owners wish to generate their own clean energy for free, from the sun. The system owner has the benefit of producing their own clean energy as the primary source of their power, but has the reliability utility grid if the system output does not meet the owners' electric demands. Grid-tied systems can also have a battery back-up system installed so that any excess electricity produced that is not used by the home or business can be diverted to charge batteries and be used at a later time. It is not necessary to have a battery back-up, but it is yet another way that the owner can be more self-sufficient.
Stand-alone systems utilize a battery system that is charged during the day when the sun is shining and stores the power for use when the sun is not available. These types of systems are typically used where there is no electricity available, such as a remote cabin, because the cost of having the utility install the system to the location can be very expensive.
Back-up PV systems are typically used where the utility grid is unreliable and has frequent blackouts. Systems can be sized to supply electricity to basic electrical devices, such as lighting circuits, or designed to be larger to serve motor loads such as refridgerators and air conditioners.