Translations:Energy storage/2/en

PV systems produce energy when the sun is shining, but their production varies significantly depending on the season and whether it is cloudy or raining. There is also the inevitable reality of the sun setting each day. Variable production requires energy storage to provide a stable energy source and voltage when the PV source is not producing power to meet the energy demand. The most common form of storage in off-grid applications is batteries. Rechargeable batteries rely on chemical reactions to release energy when it is needed, but that can be run in reverse when the battery is being charged to store energy. There are many different types and sizes of batteries in the market. This is the case because there is no single type of battery that is superior in all applications. Each type of battery has uses different combinations of materials that have different advantages and disadvantages. All battery designs inevitably have to balance the following characteristics: