1. Reasons for Using Batteries in Hybrid Microgrids
The installation of a battery system is not critical for microgrids that are connected to the electricity network. The ComAp control system automatically starts and synchronizes backup motor generators, so in case of an impending mains failure and subsequent limited power supply, a backup power supply would be switched on as soon as possible, without the power outage. However, in parallel applications, backup batteries can also play a role of uninterruptable power supply (UPS), where they feed the load until the motor generator starts (can be used in critical applications, such as hospitals, data centers, etc.).
For island systems (so-called off-grid) with renewable resources, where diesel fuel consumption reduction is a priority, the usage of batteries is crucial. A high-capacity battery (not only in the role of UPS) is then available to cover power peaks and to eliminate the need for dynamic spinning reserve. Thanks to that, the load of the motor generator remains constant, thus extending its life and reducing fuel consumption.
The above mentioned can be applied only on condition that the battery is dimensioned correctly, and a suitable technology is chosen which can reduce diesel consumption by limiting the operation of diesel engine generators. During the project design an economic return on investment has to be taken into account though since the battery storage is still relatively expensive.