Local Knowledge About Batteries & Storage

The battery stores electricity for use at night or for meeting loads during the day when the modules are not generating sufficient power to meet load requirements. To provide electricity over long periods, PV systems require deep-cycle batteries. These batteries, usually lead-acid, are designed to gradually discharge and recharge 80% of their capacity hundreds of times. The cost depends on the type, capacity (ampere-hours), the climatic conditions in which it will operate, how frequently it will receive maintenance, and the types of chemicals it uses to store and release electricity. A PV system may have to be sized to store a sufficient amount of power in the batteries to meet power demand during several days of cloudy weather. This is known as "days of autonomy." Consult with your PV dealer before selecting batteries for your system.