The East African Rift is among the most crucial regions of the world endowed with a remarkable geothermal potential. Using current technologies, East African countries have a geothermal power potential of more than 15,000 MWe. Nevertheless, the zone is still at an early stage of geothermal development with few plants producing a few hundred MWe. Among East African countries that have carried out research on geothermal resources, Kenya is leading in utilising geothermal energy resources for electricity generation. Eritrea, Uganda, Tanzania and Djibouti are at exploration stage while Malawi and Rwanda have so far not gone past geothermal resource potential record work. This study sought to address the challenges and barriers to the adoption of geothermal energy as well as the strategies to implement geothermal energy plans in East Africa.
Taguchi method is used to find the optimal cutting parameters for turning Al2124/SiCp (45%wt) metal matrix composite using polycrystalline cubic boron nitride (PcBN) and polycrystalline diamond (PCD) tools. Experiments were performed with High Precision Lathe Machine Model No: CG6125C. The parameters selected were cutting speed, feed, depth of cut, and tools. The output responses considered for the investigation were surface roughness, tool wear, and specific power consumption. Results show that the optimal combination of parameters giving the best surface finish are at cutting speed of 60 m/min, feed rate of 0.2 mm/rev, depth of cut of 0.10 mm, and PCD tool. The analysis also show that the optimal combination of parameters is at cutting speed of 40 m/min, feed rate of 0.15 mm/rev, depth of cut of 0.20 mm, and PCD tool insert give the lowest specific power. Dominant wear mechanism observed is abrasion wear affecting flank face. Uncoated PcBN had greatest wear followed by coated PcBN and finally PCD tool. Tool insert has a dominant effect on surface roughness having a contribution of 82.04% and followed by cutting speed having a contribution of 4.51%. On specific power consumption tool insert has a dominant effect having a contribution of 65.14% and followed by feed rate with a contribution of 13.57% and interaction (a p  f) with a contribution of 9.92%. It is observed that optimization of the two characteristics for machinability of Al2124SiCp (45%wt) metal matrix composite simultaneously is difficult. On tool wear the results showed that PcBN tools suffered severe wear as compared to PCD tools.
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.
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