Last week, I attended a training seminar on PV solar system organized by the Japan International Cooperation Agency (JIAC) and the Philippine Department of Energy (DOE). Although, PV solar system is capable of supplying large amount of power, like the 1 MW solar plant at Cagayan de Oro and owned by CEPALCO, the training focused only of Solar Home System (SHS) and Battery Charging System (BCS).
Energy production using the light from the sun is not a hard concept to study. You can even learn the theory of its operation by just reading a book about it. That’s it, you just need to learn some basic electric circuit theory, battery usage, and metering equipment usage. Maybe the only new thing that I’ve learned in the seminar and brought me into confusion is how the system is operated.
What had been thought in the seminar regarding the operation of the PV solar system is something like this;
The battery took the big role in supplying electricity. The load primarily draw its power from the battery and once the battery’s stored energy reach a certain level of discharge, the PV panels will then supply electricity to recharge the battery. If the battery is already full, the supply of electricity from the panels will be cut and keep it idle until such time that the battery need to be charge again. In short, the PV cells acts as only a back-up of the battery.
My idea about the operation of the PV solar system is kinda different to what had been discussed in the training. The System should be operated such that the panels will be the primarily source of the load and the battery will only serve as a back-up. That’s it, if the power that the PV panels can supply is not enough to meet the requirement of the load, the battery will backed-up and supply the additional capacity. On the other hand, in case that the electricity generated by the PV cells is greater than the demand, the excess will be stored in the battery. This way, it will reduce the charge-discharge cycle of the battery, and optimize the operation of the whole system