Photovoltaic energy generation is one of the fastest-growing green energy sources. Hundreds of MW of rooftop systems and utility-scale PV parks are installed every year. Best system availability and minimised OPEX (operational expenses) define the profitability of any size of system.
PV systems are directly exposed to environmental conditions due to the fact that they are always installed in extraordinary locations. Thus, the probability of being impacted by lightning is high. Unprotected PV systems suffer repeated and significant damage to their components. This results in substantial repair and replacement costs, system downtime and loss of revenue. Automation systems, monitoring components and PV inverters must be protected reliably and in line with current standards. IEC and UL standards define precisely the rules to be applied for implementing state-of-the-art PV installations.
The figure on the left shows the general architecture of a PV system. The table below is intended to help you select the correct surge protection products according to the specifications of applicable standards in a PV system.
L1 describes the cable length between the main distribution board and PV inverter (AC side) and L2 describes the line length between PV inverter and PV generator (DC side). With a line length > 10 m, an SPD is required on both sides by the standard.
Question 1 | Question 2 | Question 3 | Question 4 | Installation locations AC | Installation locations DC | ||
Outdoor lightning protection system present? | Separation distance observed? | Line length L1 less than 10 m? | Line length L2 less than 10 m? | SPD 1 | SPD 2 | SPD 3 | SPD 4 |
No | - | No | No | TYP II AC | TYP II AC | TYP II PV | TYP II PV |
No | - | No | Yes | TYP II AC | TYP II AC | TYP II PV | - |
No | - | Yes | No | TYP II AC | - | TYP II PV | TYP II PV |
No | - | Yes | Yes | TYP II AC | - | TYP II PV | - |
Yes | Yes | No | No | TYP I AC | TYP II AC | TYP II PV | TYP II PV |
Yes | Yes | No | Yes | TYP I AC | TYP II AC | TYP II PV | - |
Yes | Yes | Yes | No | TYP I AC | - | TYP II PV | TYP II PV |
Yes | Yes | Yes | Yes | TYP I AC | - | TYP II PV | - |
Yes | No | No | No | TYP I AC | TYP I AC | TYP I PV | TYP I PV |
Yes | No | No | Yes | TYP I AC | TYP I AC | TYP I PV | - |
Yes | No | Yes | No | TYP I AC | - | TYP I PV | TYP I PV |
Yes | No | Yes | Yes | TYP I AC | - | TYP I PV | - |