Centralized solar power plant systems / communal is an alternative electricity generation systems for remote areas that hasn’t been achieved by State Electricity Company’s network (PLN). The capability of centralized solar systems is to generate and save electrical energy, it makes this system can be relied to replace State Electricity Company (PLN). Centralized solar power plant system can be viewed like the diagram below:
Centralized solar power plant above has the main component like:
Array module : is a series solar module, which during the day will produce electrical energy and stored in batteries to be used at day and night.
Solar charge controller : is the equipment that controlling the progress of energy fulfillment from Array module to the battery or Supply energy controller.
Combiner box : is a DC voltage system panel which contains a separator switch or MCB and Arrester on both positive and negative buses. Each array passes MCB before going into bios positive and negative. For every positive bus was mounted an arrester to the grounding terminal. On the panel, there is a blocking diode which functions as a safety of backflow that could arise from a higher voltage battery at night or due to voltage variations of each array.
Inverter : is the equipment that changes DC voltage into AC in the load side.
Panel battery : Serves as a breaker or a link between the batteries with inverter.
Battery : Used for save energy in the daylight from array module for load supply.
The principle of working of generating
Generally, the principle of centralized solar power plant can be described as following.
Day : In the afternoon, the electric energy which is produced by solar module (PV) will directly distributed to the load by inverter. Some of the remaining electric energy will be used for charge the battery. The process of electric energy fulfillment from PV to the battery is regulated by solar charge controller in order not to over charge. The amount energy produced by PV is depends on the sunlight intensities that achieved by PV and cell efficiency. The maximum of sunlight intensities can reach up to 1000 watt/m2 with cell efficiency 14%, the power that can be produced by PC is 140 watt/m2.
Night : In the night, the source of solar energy cannot be used anymore, so the load will be supplied by the battery. The energy that has been saved in the battery at noon will be used for supply the needed load through the inverter. Inverter changes DC voltage on the battery side to AC on the load side.