The Most Important Components of a Solar PV System (Grid-tied Solar System and Off-grid Solar System)

 

The complete solar PV system consists not only of solar modules, which they form in their entirety the PV array. In fact, all components must be considered and coordinated to achieve the highest possible yields.

With regard to their components, we must distinguish between an off-grid solar system and grid tied solar system.

 

Off-grid solar system

 

 

An off-grid solar system is not connected to the public grid. Therefore,  it differs from grid-tied solar system in essential components. An off-grid solar system consists of:

• Solar modules – these are connected together to form strings, which again are coupled to PV array.

 

 

• Generator connection box – here the solar modules are interconnected to the PV array.

 

 

• Cabling – at this, it must pay attention to the cable cross-section, which is dependent on the size of the PV array and the cable. Besides, the cable between the solar power inverter and the solar battery must be selected that it is suitable for the high powers.

 

• Energy storage – the energy storage or battery plays an essential role in the off-grid solar system because the battery supplies the loads with power when no solar power is produced. The dimensioning depends on the size of the PV array and the energy demand.

 

 

• Charge controller – are important to increase the lifetime of batteries. In the off-grid solar system, charge controller avoids deep discharging or overloading of the battery. Charge controller must harmonized with the chosen Besides, they are dimensioned in such a way that they fit with the maximum current of modules and the loads.

• Off-grid solar inverter – is needed to operate AC loads in an off-grid solar system.

 

 

Grid-tied solar system

 

In a grid-tied solar system are some components similar as of an off-grid solar system, some fall away, other components are added.

• Solar modules – these are connected together to form strings, which again are coupled to PV array.

• Generator connection box – this is also important in the grid-tied solar system. Here can also be found fuses for the strings.

• Cabling – the DC cabling is the cabling between the modules and the solar power inverter. The AC cable is the cabling from the solar power inverter up to the feed point. Even here, the cable cross-section depends on the output of solar modules,  of the inverter and the cable length.

• Grid-tied solar inverter – the inverters are certain components, which co-determine the efficiency of the entire plant.

 

 

• Feed-in counter – in a grid tied solar system, it needs to be measured, how much power can be fed into the utility grid. This task is assumed by the feed-in counter.
• Feed-in management – offers a remote monitoring possibility by the grid operator.

• Energy storage – is an optional component to store the excess of power by day and to use it at night. Here, es is also essential to control the charge/discharge.