Solar power is stored in deep-cycle batteries or battery banks, in a grid-tied system or in the power grid itself. Batteries can be utilized for both on- and off-grid systems.
Batteries require four major components to function correctly and store solar power. Component one, the charge controller, prevents the batteries from overcharging when they are full. Component two, the actual battery, is a team of deep-cycle cells wired together. Deep-cycle batteries are built to last roughly ten years and be discharged up to eighty percent of their capacity on a regular basis.
Component three, the system meter, measures and displays the status of the collected solar power as well as the performance of the power. Component four, the main DC disconnect, acts as a breaker between the battery and the inverter that turns the solar energy into AC power. This breaker allows the battery bank to be disconnected for maintenance.
Passive and active solar water-heating systems use water tanks to store solar energy, just as swimming pool solar heat systems use the actual pool water to store the energy. Both types of systems are capable of using a thermal mass storage system that accumulates solar energy during the day as heat and then releases it slowly for use at night.