Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
The fact that most of the large scale solar PV plants are built in arid and semi-arid areas
where land availability and solar radiation is high, it is expected the performance of the PV
plants in such locations will be affected significantly due to high cell temperature as well as
due to soiling. Therefore, it is essential to study how the different PV module technologies
will perform in such geographical locations to ensure a consistent and reliable power
delivery over the lifetime of the PV power plants.
As soiling is strongly dependent on the climatic conditions of a particular location a test
station, consisted of about 24 PV modules and a well-equipped weather station, was built
within the fences of Scatec’s 75 MW Kalkbult solar PV plant in South Africa.
This study was performed to a better understand the effect of soiling by comparing the
relative power generation by the cleaned modules to the un-cleaned modules. Such
knowledge can enable more quantitative evaluations of the cleaning strategies that are
going to be implemented in bigger solar PV power plants.
The data collected and recorded from the test station has been analyzed at IFE, Norway
using a MatLab script written for this thesis project. This thesis work has been done at
IFE, Norway in collaboration with Stellenbosch University in South Africa and Scatec
Solar a Norwegian independent power producer company.
Generally for the polycrystalline modules it is found that the average temperature
corrected efficiency during the period of the experiment has been 15.00±0.08 % and for
the thin film-CdTe with ARC is 11.52% and for the thin film without ARC is about
11.13% with standard uncertainty of ±0.01 %.
Besides, by comparing the initial relative average efficiency of the polycrystalline-Si
modules when all the modules have been cleaned for the first time and the final relative
efficiency; after the last cleaning schedule which is when all the reference modules E, F, G,
and H have been cleaned for the last time it is found that poly3 performs 2 % and 3 %
better than poly1 and poly16 respectively, poly13 performs 1 % better than poly15 as well
as poly5 and poly12 performs 1 % and 2 % better than poly10 respectively. Besides, poly5
and poly12 performs a 9 % and 11 % better than poly7. Furthermore, there is no change
in performance between poly6 and poly9 as well as poly4 and poly15. However, the
increase in performance of poly3 to poly1, poly13 to poly15 as well as poly5 and poly12 to
poly10 is insignificant.
In addition, it is found that TF22 perform 7% better than the reference un-cleaned module
TF24 and similarly; TF21 performs 7% higher than TF23. Furthermore, modules with
ARC glass (TF17, TF18, TF19, and TF20) shows that cleaning the modules with only
distilled water (TF19) or dry-cleaned after cleaned with distilled water(TF20) decreases the
performance of the modules by 5 % and 4 % comparing to its respective reference uncleanedmodules TF17 and TF18 respectively.
2016.