Performance ratio (PR) is the most important parameter of a solar PV plant. Every investor’s primary focus is about PR and EPC contract provides the guarantee of PR of the plant. Although no of software are available in the market which are able to calculate the performance ratio of the plant but from an investor and EPC contractor eye, it is worth to understand the performance ratio and right way to calculate it. Here, in this article, I have used PVSYST, well known and widely used software for the designing and analysis solar PV plant and cross check the manually calculated values with the PVSYST results.
Performance ratio (PR) is the factor through which you can assess the plant performance, how the plant is behaving. If a plant has a performance ratio of 80%, it shows that 20% energy generated through the PV panels is lost in the system losses.
There are two basic parameters to calculate the performance ratio Y f (Final PV system yield) and Yr (Reference yield). PR is the Ratio of Y f and Yr .
Performance ratio = Y f/Yr
Y f = E/P0
E= Net energy Output in KWh
P0= Installed PV array in KW
H= Total plane irradiance in KWh/m2
G= PV reference irradiance in KW/m2
Take a 1 MW PV plant for calculating the performance ratio. E is taken from PVSYST generated report and P0 is 1 MW. H is taken from the PVSYST table and G is the value at STC which is 1000 W/m2.
Manual calculation result to 74.9% and software is also showing the same value.
Posted by: Er. Gaurav Sharma , firstname.lastname@example.org