Hi Guys, welcome to Minutes 2 Energy. We are a team of Solar professionals with

more than 10 years of experience in technology and business fields and today we are going

to share our knowledge and experience with you. Please see the video till the end for useful

resources. So, let's start!! Today’s topic is Solar Plant Performance

Ratio or in short PR. PR is a very important tool or factor that

being used globally by companies and professionals to assess the healthiness of Solar PV system.

So let’s know how this PR is calculated

and how it is so important for Solar PV System. So what is Performance ratio or the PR for

Solar PV Power Systems? PR is the Ratio of Effective Produced Energy

to Ideal Energy Yield at STC Condition. As it’s a Ratio it is Unit less and globally

it is being denoted as a Percentage value. Here the term Effective Energy is the available

Useable Energy delivered to the Grid or to the End User. While calculating the PR all the losses like

Optical losses PV array Losses DC to AC conversion losses and the other System losses are taken

into Account. Please follow our other videos for detail

info on Different types of system losses.

Simple Annual PR measured on the basis of

Actual Annual useable energy and the Annual Solar Irradiance

Now let’s see the Formula of PR. So PR is equals to E Grid divided by the product

of GII and P Nom PV. Here E Grid is the Useable energy available

at the User End. Unit of E grid is kilo Watt hours per year. GII refers to the Global Inclined Irradiation

received by the Solar PV array at certain tilt angle. Next is P nom PV. This is Solar PV array’s installed DC capacity

and denotes as kilo Watt Peak.

Next is the types of PR which are there for

their own significance and applicability. So let’s know more about them. First is STC Equivalent PR. It is determined by adjusting the power at

each recording interval to compensate for difference between the actual PV module temperature

and the STC reference temperature. This method normally used when the System

PR is to be measured at a short duration of day time. Annual Temperature corrected PR is similar

to the previous one. Here PR is calculated by adjusting the reporting

period with respect to power to compensate for the difference between the actual PV module

Temperature and the expected annual average module temperature.

Annual Temperature correction is significant

when the Annual PR is required to be Validated for within 15 to 20 days of operation. Now let’s look at an example of how to calculate

simple annual PR with available plant operational data. For any given year and location say from a

one thousand kilo watt peak Solar PV On-Grid installation the annual Global Irradiance

received at the PV plane is 1875 kilo Watt hours per meter square per year and the useable

energy fed to grid is 1540 Mega Watt Hours. Now here the E grid is 1540 megawatt hours

or 1540 into 1000 kilo watt hours per year. GII is 1875 kilo Watt hours per meter square

per year and the P nom PV is one thousand kilo watt peak. Then the yearly PR Should be calculated as

1540000 divided by open bracket 1875 multiplied by 1000 close bracket. Which is 0.82 or 82%. So hope you now understand how to calculate

Annual Performance ratio of solar Plant. Please see our other video on How to Calculate

PR in MS Excel for more detailed understanding. The Solar Plant Performance Ratio is defined

in the norm IEC EN 61724.

Please follow the latest edition that is IEC

61724-1 (2017 edition). Link to get the standard from IEC webstore

is in the description below. Now let’s talk about Few Points you should

keep in mind while assessing the Solar Plant Performance Ratio. First PR always represented as Percentage. Second PR is a Ratio of actual energy generated

to the ideal energy Yield for a given period. And the third one is that it is independent

of location’s specific Irradiance level. So What is the Significance of Plant Performance

Ratio? Well The PR is an important metric in the

PV industry it is often used as a contractual condition / contract warranty when commissioning

a PV system Irrespective Of System Size Or System Type whether be it ground-mount or

rooftop based Grid-connected or Off-grid be it a small rooftop system or even an Ultra

Megawatt utility scale solar plant.

Also we professionals always check PR for

the HEALTHINESS of the plant and to VERIFY the annual energy yield. So this is all about Solar Plant Performance

Ratio. To know more about the PR please see these

videos. We have put the links to the videos in the

description below. Please let us know how did you find this video

helpful in the comment section. We read all of your comments. And please please like and share the video

as much as you can!! Do subscribe to our channel minutes to energy

for more interesting videos on Solar PV system. Thanks for watching guys till the end. See you in the next video..