Solar Energy Storage

Solar energy is an abundant source of energy. Solar energy fluctuation and its inconstant radiation intensity are important factors in the use of solar energy. For example, the radiation intensity in one place varies depending on season, weather, day or night. In general, it is difficult to reconcile energy needs with the availability solar energy. Therefore storage of solar energy is one of important issues of solar energy application study. Solar energy storage can be classified into three major groups:

1. Sensible Heat Storage

In the solar system with low and medium temperature, water and stone are type of storage medium give us the cheapest and the best performance. Solar energy collectors collect the heat so that the temperature of the medium increased. This temperature increase indicates that medium store heat energy. When needed, heat energy can be released from the medium. The weakness of this type of storage is in their short storage time.

2. Latent Heat Storage

For this type of storage, heat storage medium must be able to absorb heat in large, small variety of volume, little corrosion, and can be re-used. Currently, the medium used is sulphate, nitrate, and hydrate carbonates. The latent heat storage has high energy storing density and long storage period.

3. Chemical Reaction Energy Storage

On this type, endothermic chemical reaction is used to store heat energy. When the process reversed, heat can be released. Chemical materials used for this purpose are inorganic oxides. The advantages of this process is the large storage capacity and a long storage time. However, the high temperatures required for endothermic reaction takes the high cost.