Solar energy storage requirements are exhibiting rapid growth. By adding batteries to a residential grid-connected solar system gives the system the ability to provide continued power when the electrical grid is down. Solar energy storage can also assist commercial enterprises to reduce peak time demand charges, levied by electricity companies to significantly lower their electricity accounts. “Off the grid living” is becoming less of a major issue, however it is still expensive so in S.A. It is still more cost effective to have a combination of Eskom, Solar Panels and batteries, known as a hybrid system.
Batteries for Photovoltaic energy storage
If a solar system produces more energy during the day than is consumed by the household or commercial enterprise the unused energy can be stored in batteries for use at night or in a system designed for backup, during a power failure.
The batteries used in solar systems need to meet the demands of an unstable grid energy, which causes heavy cycling (charging and discharging) and irregular full recharging. There are various types of batteries designed specifically for these unique requirements. In order to make the correct choice when choosing a battery the following should be considered:
- Cycle life (The cycle life is the number of complete charge/discharge cycles that the battery is able to support before that its capacity falls under 80% of its original capacity)
- Installation and maintenance.
Calculating energy storage capacity required
This is affected by the energy usage during the day, the size of the solar system and the intended use of the stored energy and when the energy will be utilised. It is vital that this is calculated correctly, to ensure that the load of what you intend to power is catered for and therefore should be done by professionals.