dc.description.abstract |
Solar Photovoltaic (PV) system is one of the most promising renewable energy
resources globally. However, its utilization has remained low in Kenya. This may be
attributed to lack of pertinent knowledge of the potential, opportunities,
environmental, and economic benefits of the technology. The PV performance,
degradation, and reliability in the East African region have not been documented and
little information is available in the literature. The main objective of this research was
to determine the performance, degradation, and reliability of solar PV modules under
environmental field conditions. The specific objectives were to; evaluate the technical
and economic performance of PV modules, analyze the effects of soiling on the
performance of PV modules, determine the reliability, degradation rates and
mechanism of PV modules. The study area was in Makueni County (semi-arid region),
Strathmore University solar PV power plant, and Moi University (tropical-savanna
region). The methodology involved review of the historical data of PV power plant and
collection of weather data from Kenya Meteorological Department weather station
located 300 metres from the solar plant. Secondly, installation of weather station and
six PV modules was done in Moi University to establish the effects of soiling. The
analysis of the contaminants collected from the PV modules was done using sieves
and analytical balance weighing machine. Finally, the measurement of I-V curves,
thermal images and visual inspections was conducted on the PV modules installed for
more than 1 year. This was done through the use of I-V curve tracer, Infrared camera
and PV module check list tool developed by National Renewable Energy Laboratory.
The results indicated a performance ratio of 68% and a discounted payback period of
13 years. The model developed indicated that an increase in solar irradiance and wind
speed, and decrease in relative humidity, increases the power output. The degradation
rates ranged from 0.99% to 1.15%, per annum, which was due to different types of PV
cell technology, while degradation mechanisms were established as discoloration of
encapsulating materials (36.84 %) in warm semi-arid region and browning of
encapsulating material in tropical savanna as the predominant mode. The contaminant
contained high percentage of fine particles of less than 0.06 mm in size which caused
reduction of short-circuit current. The reliability of the different PV system installation
configurations ranged from 35% to 82%, indicating a weighted mean of 67%, which
was due to number of components, and connection schemes, majority of modules
being polycrystalline. In conclusion the results obtained, provided clear evidence of
the technical and economic viability of PV modules in the region as a source of energy.
The study recommends parallel connections of components, and regular cleaning to
maintain high performance and reliability, and reduction of degradation rates in the
region. |
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