How does a solar PV power plant work

A solar PV power plant works based on PV technology which converts solar energy directly into electricity using semiconductor materials. It works on the principle of the photovoltaic (PV) effect. When certain materials are exposed to light, they absorb photons and release free electrons. It is known as the photoelectric effect. Photovoltaic effect is a method of generating direct current electricity based on the principle of the photoelectric effect. Solar cells or photovoltaic cells are made based on the principle of photovoltaic effect,  They convert sunlight into direct current (DC) electricity. As single photovoltaic cell can't produce enough amount of electricity, a number of photovoltaic cells are electrically connected to each other on a mounting structure or a frame to form a photovoltaic module or solar panel. Solar panels available in the market are ranged from hundred watts to few kilowatts in general. They are available in different sizes and price ranges. Solar panels or modules are designed to supply electric power at a certain voltage level (12v), but the production of current directly dependents on the incident of light. So far it is clear that photovoltaic modules produce DC electricity. But, AC (Alternating Current) power is also required in homes, offices and industries to run some appliances. In this scenario, an inverter is also required in a solar PV power system.

In order to get maximum power from solar PV module, multiple solar PV modules are electrically connected together to form a PV array. There are different types of PV systems according to their implementation. They are as follows: 

• PV direct system: In this system, PV module can only generate power and supply electricity based on the availability of sun rays. In this case,batteries are absent as there is no storage of power generated. Based on the load, an inverter may or may not be used.
  
• Off-grid system: This type of system basically used at locations where power from the grid is not available or not reliable. An off-grid solar PV power system is not connected to any electric grid. This system includes solar panel arrays, storage batteries and inverter circuits.
• Grid connected system: Here, the solar PV power system is tied with grid so that the excess required power can be accessed from the grid. In this case, batteries may or may not be used for back up.