There are three types of photovoltaic systems such as off-grid, grid-tie, or hybrid. Off-grid systems fully self-contained with no reliance on the electrical grid. In these systems the power you generate either goes into batteries or you use it directly. In a grid-tie system your generated power goes directly into the electrical grid, and you get credit for it, but you draw from the grid at night. A hybrid system uses both backup batteries and a grid-tie system. The only elements common to all systems are some form of inverter and the solar panels themselves.
1. PV Generator
The main element of the system that converts sunlight into electrical energy is PV Generator. In 1950s, Pv Generator had about 4% efficiency and today it is about 15% system efficiency. Its efficiency is calculated according to 1000 W/m2 of energy is emitted by the sun and in Turkey this value has more efficiency and it is about 1300W/m2.
In addition, the sunshine duration for Turkey conditions has more experienced variability. In winter, it is approximately 5 hours, 7 hours in the fall and summer is around 11 hours. To get maximum efficiency, the system needs optimum environments and conditions. However, to get more efficiency from this system, the placement of PV panels are important factor.
2. Charge Regulator
You don’t need a charge controller if you don’t have batteries for storage–ie, if your electricity goes straight into the grid and isn’t a hybrid system. The charge controller protects your batteries by monitoring how much they’re being charged and slowing or even halting flow to avoid overcharging. This helps the batteries last longer so that they can efficiently store what you generate. The charge regulator from the PV panel current (energy) allows the transmission to the battery, the battery fully discharged. Charge regulators are chosen according to the system used (12A, 24A, 48A or 10V, 20V, 40V, 60V) and it must be stable to the maximum current.
Inverters convert the DC current from solar panels and batteries into AC for use by a house or electrical grid. If the electricity is to be used by the grid, you need a special grid-tie inverter. The grid-tie inverter matches the phase of the electricity you generate to the phase of the grid. Without it, the mismatched phases would effectively cancel one another out and be useless.
The grid-tie inverter also acts as a safety device; if there is a power cut, it will immediately switch off the solar panel supply so that the electricity you generate doesn’t harm a worker trying to fix the power lines.
4. Batary System
Generally, it is used off-grid or hybrid photovoltaics with using of a bank of deep-cycle batteries to store electricity from solar panels. Electrical energy is produced by solar panels during the day/night without interruption is possible to use the proper battery bank with its establishment. With serial or parallel connection of batteries, system can work 12, 24, 48 or 120V voltage. It is generally three types such as Flooded Lead Acid, Absorbed Glass Mat Sealed Lead acid(AGM) and Gelled Electrolyte Sealed Lead Acid(GEL). But in photovoltaic systems, flooded lead acid is prefered. This type of batteries do not need to add distilled water and electrolyte, charge-discharge kinetis of long lived and very productive.
Furthermore, such products are avaliable in different locations at the same time is ideal for applications that require high-performance solutions. Batteries shouldr be directed to the system to be established during the selection of it. For example, during a day, a gel battery-powered lamps should be chosen for street lighting or garden. Because acid batteries do not need appropriate choice due to make a care four or six months (the addition of distilled water). Flooded lead acid batteries can be used if there are only solar applications and if it will be maintananced.