Components of a Rooftop Solar Power Plant

Solar power generation system includes:

  • Solar module (array)
  • Controller
  • Batteries
  • Inverter
  • Lighting load that is composed of the user.

Among them, the solar battery components and batteries are for the power system, controller and inverter for the control and protection system, the load for the system terminals.

Solar module Solar PV cell is the basic building block of a PV system. It consists of semiconductor material that absorbs sunlight to generate electricity. A basic PV cell produces a very small amount of electricity and multiple of them are connected together to generate 10W to 300W output. If more electricity is required, then multiple such PV modules have to be installed in an array.
Controller A charge controller regulates the DC power output from the rooftop solar panels and stabilizes it to charge the batteries. It provides optimum charging current, and protects the batteries from overcharging. There are two kinds of charge controllers :

  • Pulse Width Modulated (PWM)
  • Maximum Power Point Tracking (MPPT)

MPPT charge controllers are more expensive than PWM but they are much better than MPPT.

Batteries “Deep Cycle” batteries (generally lead-acid) are the best suited for a solar PV system. They last for 5 to 10 years and are 80% efficient (can reclaim 80% of energy stored in it). These batteries are also designed to provide electricity for long periods and can discharge up to 80% of their capacity repeatedly.
Inverter Inverters are a very important component of your rooftop solar PV plant because they determine the quality of AC power you get.
Inverters are not 100% efficient and it is important to choose the right inverter that is at least 85% efficient. A modified sine wave or a pure sine wave inverter is better suited for a roof top solar PV system. Modified sine wave inverters are cheap but less efficient. Pure sine wave inverters are most efficient but are expensive.