Step by step building an Aurora’s diagram with considerations that affect each type of these losses

A revision of Aurora's Diagram (Steps to build)

Calculating performance ratio and specific energy production.

Performance Ratio

It is the efficiency of the PV plant =

                                                       Output Energy (Electricity)/Input Energy (Irradiance)

It is an indicator for the operation of the whole PV plant and for the individual parts.

Performance Ratio Calculation

PR = E gen (supplied to grid per year) in kWh / (Irr on tilted surface * Prated)       OR

PR = E gen (supplied to grid per year) in kWh / (Irr on tilted surface * Total Area  (m2) * Efficiency of PV modules))

Irr = Global Incident Irradiance in the plane of array (kWh/m2)

Prated = The array rated power in kWp at STC (from name Plate)

EXAMPLE:

Project capacity = 200 kWp; Annual Energy Production 360 MWh; Irr = 2300 kWh/m2

PR = 360 *1000/2300*200 = 0.7826

Specific Energy Production

The specific energy production of the PV plant =

                                                     Output Energy (Electricity)/Rated Power of the PV Plant

It gives an answer for

How many kWh will be generated for each kWp ?

SEP (kWh/kWp) = E gen (supplied to grid per year) in kWh / Prated (kWp)

What are factors affecting SEP?

Location; Installation; Losses

What is the relation between PR and SEP?

Usually in hot areas: Irr is high, Temperature is high; SEP is high whereas PR is low

             in cold areas : Irr is low, Temperature is low; SEP is low whereas PR is high


PR (%)

SEP (kWh/kWp)

Location

80.5

1600

Palestine

78.2

1655

Oman

82.3

1350

America