Photovoltaic (PV) modules deployed outdoors can degrade due to exposure to the various elements. This includes exposure to UV light, a range of fluctuating temperatures and humidity and exposure to a range of operating currents and voltages. Different weather conditions have an important influence on degradation rate. Evidence indicates that both degradation and failure mechanisms are location dependent. This paper presents a research investigating the prevalence of various forms of physical degradation experienced by photovoltaic panels which have been in operation in Kenya under various climatic conditions. To study degradation of PV systems, identification and analysis of modules that had been deployed in various locations in Kenya, and which had been in operation for at least the last 2 years was carried out. Imaging instruments were used to study visible signs of weathering and other physical defects. The results indicated that despite the fact that panels are designed to operate in outdoor environment, numerous cases do exist whereby the panels degrade physically, in various ways, and consequently exhibit total failure, diminished performance or just physical manifestation of wear. Apart from manufacturer defects, user ignorance on installation and usage was also proved to contribute to the diminished life span of some panels.

Many photovoltaic solar projects do not achieve optimum energy and power outputs due to poor technical sizing and system design approaches. Concerns on low-conversion rates, high intermittencies, and high-capital costs still haunt PV projects. The establishment of design methodologies that would result in increased outputs from solar arrays is crucial in addressing the aforementioned issues. The tilt angles of installed PV modules are critical factors that influence the power output of solar modules. Several resources are available that provide generic linear fits and estimation of tilt angles for various global regions. However, very few are capable of determining precise, location-specific tilt angles that would allow for optimal power output and energy generation. This paper presents a methodology developed to establish the optimum tilt angles for solar panels installed at specific locations, thus ensuring maximum energy generation. The modeling is based on the maximization of the solar irradiation incident on the surface of a PV panel by considering multiple site-specific variables. Different sets of transcendent equations have been derived which were used to calculate optimum tilt angles and the subsequent energy generation from specific configurations of photovoltaic arrays. The resulting algorithms were used to determine optimum tilt angles and energy generation for solar PV installations in Athi River, Kenya. Dynamic and static optimal tilt angles were compared with the region’s baseline industry practice of using a fixed tilt angle of 15◦. It was observed that the dynamic tilt angles improved the daily solar energy output by up to 6.15%, while the computed optimal static tilt angle provided a 2.87% output increment. This improvement presents a significant impact on the technical specification of the PV system with a consequent reduction in the investment and operational cost of such installations. It further demonstrated that the use of the optimum static tilt angle results in cost and space savings of up to 2.8% as compared to the standard industry practice. Additionally, 5.8% cost and space savings were attained by the utilization of dynamic tilt angles.

The tea industry in Kenya is among the main consumers of firewood for its intensive thermal energy demand. Along with the growing concerns about firewood depletion, tea factories have begun transitioning to alternative fuels to power their boilers. Briquettes made of biomass residues are among the promising solutions; however, they are not yet widely adopted. This study was conducted to identify the factors that motivate the tea factories to use biomass briquettes instead of firewood and the factors hindering such substitution. The substitution potential was assessed, and the drivers and barriers of the substitution were examined using a combination of SWOT (strengths, weaknesses, opportunities, and threats) analysis and a PESTEL (political, economic, social, technological, environmental, and legal) framework. The findings suggest that even though using biomass briquettes is technically possible, it is not economically favorable for tea factories. The SWOT/PESTEL analysis identified 27 factors influencing the substitution. Among the key drivers are the depleting supply of firewood, the availability of biomass residues, and the external support from development organizations to improve the technical capacity in both tea and briquette industries. The study revealed the barriers to substitution include the cost competitiveness, insufficient supply, and varying quality of briquettes, as well as the lack of awareness and knowledge of briquettes.

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