NRG INSTRUCTIONS
SRA System | Soiling Measurement Kit
SRA Soiling Measurement Kit Instructions
Rev. 6.0
[email protected] | Page 20
19 December 2018
3.1.3 Saving the Channel Configuration
When all the channel configurations have been edited and are ready, click the “Save To Logger” button
at the top of the Channel Configuration page.
Note: It is a good idea to save the .LGR configuration file on your computer as well as to the logger.
Go
to
the Logger drop down menu in the upper right hand corner of the application screen and select
“Save Instrument Configuration File.”
SITE MAINTENANCE
Back-of-panel temperature and short-circuit current for each panel are continuously measured by the
system, and (typically) averaged every one minute.
The clean panel should be regularly cleaned thoroughly with deionized water and a soft non-abrasive
cloth (about once a week or as recommended by your analyst). Deionized water is free from calcium
and salt so it will not leave deposits on your PV panels.
Certain sites may have very abrasive mineral deposits, so be mindful of abrasion when cleaning the PV
panels.
Rainfall also has a natural cleaning effect and should also be recorded at the site with an instrument
such as a tipping rain bucket connected to the same data logger.
DATA PROCESSING
The measured values (Temp CLEAN, Isc CLEAN, Temp SOILED, Isc SOILED) can be used to determine a
Soiling Ratio which compares the soiled PV output to the clean PV output. By monitoring the soiling
ratio over time and using additional analysis techniques, the potential impact of soiling losses on a PV
farm’s energy production can be characterized.
For a quick check, the simplest of methods is to divide the soiled PV Isc by the clean PV Isc. Note that
other, more complex methods are often utilized.
