Matching the Energy Demand of Surrounding Villages with Hydropower Potential of the Un-Gauged Myombwe River

Energy demand of twelve villages surrounding Magunguli waterfalls along un-gauged Myombwe River was assessed and matched with energy hydropower potential available. Estimation of the energy demand for the villages around was done by using diversity factor analysis covering common factors for grouped potential users. A questionnaire was used to find the number of potential electricity users in these twelve villages. Then diversified unit load and group diversity factors for classified loads were used to actual power demand. The study area has 3,747 households, while dispensaries are 8. In addition to that, there are 17 primary schools and 4 secondary schools. The current power demand of twelve villages is 1,569.24 kW. Energy demand forecast shows that, the demand will grow to 7,846.2 kW after four years will be 33,924.16 kW after 25 years. It was also noted that the average consumption for a household is 129.4 W. For education sector, the total demand is 122 kW at an average of 5,851 W per school. Commercial uses have the total demand of 790.34 kW while for public services total demand is 171.82 kW. With the gross head of 636 m and 1.98 m3/s discharge, hydropower potential of Myombwe River was realized to be 9,388.68 kW. Therefore, this power generation can suffice optimum energy demand of the twelve villages for 4 years. Thereafter, additional source of power may be required. Keywords: Hydropower potential, energy demand, un-gauged river

Effects of Methyl-blue Addition in Sewage Substrate on the Performance of Microbial Fuel Cell

Experimental study was undertaken to evaluate performance of microbial fuel cell. Without addition of methyl blue, the cell generated 1.265 V, 0.403 mA and 56.12 mW/m2 after three hours of operation. With 300 µM methyl blue in sewage anolyte, 6.7% increase in voltage, 20.5% increase in current and 28.6% increase in power density was observed. By using ash- water catholyte, addition of methyl blue in anolyte led to increase of 9.0% in voltage, 38.5% in current and 50.9% for power density. Between three and twenty four hours of continuous operation of the cell with phosphate buffer catholyte, the average voltage was 1.305 V and the average current was 0.321 mA before addition of methyl blue. Methyl blue addition led to 5.1% increase in voltage and 55.2% increase in current. For the case of ash-water catholyte with methyl blue in anolyte, led to 6.2% increase in voltage and 59.1% increase in current

Matching The Energy Demand of Surrounding Villages With Hydropower Potential of The Un-Gauged Myombwe River

Energy demand of twelve villages surrounding Magunguli waterfalls along un-gauged Myombwe River was assessed and matched with energy hydropower potential available. Estimation of the energy demand for the villages around was done by using diversity factor analysis covering common factors for grouped potential users. A questionnaire was used to find the number of potential electricity users in these twelve villages. Then diversified unit load and group diversity factors for classified loads were used to actual power demand. The study area has 3,747 households, while dispensaries are 8. In addition to that, there are 17 primary schools and 4 secondary schools. The current power demand of twelve villages is 1,569.24 kW. Energy demand forecast shows that, the demand will grow to 7,846.2 kW after four years will be 33,924.16 kW after 25 years. It was also noted that the average consumption for a household is 129.4 W. For education sector, the total demand is 122 kW at an average of 5,851 W per school. Commercial uses have the total demand of 790.34 kW while for public services total demand is 171.82 kW. With the gross head of 636 m and 1.98 m3/s discharge, hydropower potential of Myombwe River was realized to be 9,388.68 kW. Therefore, this power generation can suffice optimum energy demand of the twelve villages for 4 years. Thereafter, additional source of power may be required. Keywords: Hydropower potential, energy demand, un-gauged river

A Model for Sustainable Adoption of Solar Photovoltaic Technology in Tanzania

Solar photovoltaic (PV) technology has been used for several decades to meet the electric energy need of various communities in Tanzania, particularly in rural areas that face a supply gap, due to various reasons. This study builds on three previous     projects that were implemented at different locations of the United Republic of Tanzania. These projects are the Sustainable Solar Market Packages 1 (SSMP 1) Project, which was implemented in Sumbawanga District; the Sida/MEM Solar Project, which was implemented in several regions of Tanzania Mainland and the UNDP/MEM Solar PV Project, which was implemented in Mwanza region. The aim was to develop a sustainable model for enhancement of the solar PV technology adoption in Tanzania. The model was developed based on the identified barriers that hinder the adoption of solar PV technology and adopted the best strategies from successful projects. Further, the drivers and activities were developed based on selected best strategies from successful projects. The identified barriers to the adoption of solar PV technology were grouped into five categories based on their significances. These include; limited access to finance (32%), weak enforcement of relevant policy and regulations (31%), technical capacity (18%), lack of awareness (9%) and other social drivers (10%). The analysis of information and data that was obtained from the project reports shows that there are prevailing challenges on awareness on solar PV technology and non-enforcement of quality standards. However, major barriers are on the high price of solar PV systems and lack of access to finance. A model for adoption of solar PV technology in Tanzania was developed and tested by validating it with a successfully implemented solar PV project in Tanzania. In the validation, thirteen (13) out of twenty-one (21) activities of the UNDP/MEM Solar PV Project demonstrated the moderate compliance with the model prescription by 62%. The UNDP/MEM Solar PV project developed a financing mechanism but it was not sustainable due to low application of sustainable adoptions strategies. Also, most of the strategies lacked some important drivers and activities due to financial constraints and technical know-how. The mechanism was not opening opportunities for new users to adopt the solar PV technology or maintain the existing ones. Moreover, stakeholders have not put in place the conducive conditions for existing projects to be sustainable. Recommended future interventions include application of the developed adoption model for Solar PV by using data from other solar PV projects for sensitivity analysis of identified barriers and best strategies

Effect of Ambient Reynolds Number on Small Wind Turbine Subjected to Low Wind Speed Conditions

Wind flow over the airfoil surface is adversely affected by the differences between the design and ambient values of a dimensionless quantity called Reynolds number. Wind turbine designed for high Reynolds Number shows lower maximum power performance when installed in low-speed wind regime. Tanzanian experience shows that some imported modern wind turbines depict lower power performance compared to the drag-type locally manufactured wind turbines. The most probable reason is the difference between design and local ambient Reynolds numbers. The turbine design parameters have their properties restricted to the range of Reynolds numbers for which the turbine was designed for. When a wind turbine designed for a certain range of Reynolds numbers is made to operate in the Reynolds number out of that range, it behaves differently from the embodied design specifications. The small wind turbine of higher Reynolds number will suffer low lift forces with probably occasional stalls. &nbsp

Performance of Calcium Chloride- Ammonia Adsorption Refrigeration System

An experimental study on the performance of calcium chloride-ammonia adsorption system is described. A single bed water cooled condenser adsorption refrigerator prototype, which utilises calcium chloride-ammonia pair has been developed and tested in the laboratory. Experiments have been conducted for desorption temperatures of 100 °C with desorption time varying from 1 to 4 hours. An electric tape heater and a timer were used to perform the experiments. The adsorption temperature profile, adsorption rate and prototype performance have been analysed and discussed. The tested heating and desorption temperature of 100 °C and heating and desorption time of 1 to 4 hours was able to create a cooling effect of the cold chamber of the prototype of between -0.8 to 8.3 °C, which is adequate for vaccine storage requirement of 2 to 8 °C. The estimated Coefficient of Performance of the system ranges between 0.025 and 0. 076

Analysis of Performance Characteristics Predicted From Several Experimental Data and Conversion Methods for Pumps as Turbine Application Using Statistical Techniques

Different performance characteristics have been indicated when running centrifugal pumps in the reverse direction. The water flows from the discharge side of the pump to the suction side to run in the reverse direction and generate the mechanical rotational energy for the micro-hydropower plant. The current study evaluates the extent of variation of performance characteristics predicted by several experimental data from different pump-specific speeds and conversion methods. The performance characteristics discussed include the head, flow rate, efficiency and specific speed. The flow rate and head of a pump operating in pump mode divided with the characteristic of the pump operating in the reverse mode, at the best efficiency point, the resulting coefficient of determination (R 2 ) values were of 0.890 and 0.708, respectively. Also, the graph of head versus flow rate coefficients, which is a second- order polynomial function, has shown the value of R 2 of 0.954 for pump-specific speed ranging between 9 and 94 rpm. However, the pump in the reverse mode has smaller performance characteristics for efficiency and specific speed compared to the pump mode operation with R 2 of 0.966 and 0.999, respectively. Furthermore, schematic empirical statistical models were developed to predict the performance characteristics of several conversion methods using pump data obtained from the manufacturers

Assessment of hydropower resources in Tanzania. A review article

The hydropower resources have become an attractive means of generating electricity to the off-grid network, especially in rural areas. This article assesses the small, mini and large hydropower resources and identified to reach 5.3 GW for electricity generation in Tanzania. The technology development discussed comprises of hydro turbine manufacturers, classification and turbine selection. The barriers presented include the presence of sediment in the hydropower reservoirs, financial viability, policy and regulatory issues related to hydropower development. This reviewed article serves the investors and policymakers to understand the status of hydropower resources in Tanzania

Catalytic tar conversion and the prospective use of iron-based catalyst in the future development of biomass gasification: a review

This research article published by Springer Nature Switzerland AG., 2020Biomass is a promising renewable energy source which is available globally, mostly in developing countries where access to clean and affordable energy is a critical problem. Biomass gasification is an interesting technology that can convert biomasses to a more versatile fuel known as syngas, the energy which can substitute conventional fossil fuels in the future. Syngas can amenably be combusted to produce power and heat as well as a feedstock for synthesis of chemicals and other fuels. The biomass gasification is facing severe operational challenges, one of the problems being tar formation and its removal techniques. Tar condenses at reduced temperature, thus causing blockage in the downstream equipment such as compressors and engines. Many studies have considered syngas cleaning by physical removal and thermal cracking unsuitable as they need downstream processing of scrub liquor and utilizes a part of the produced gas in maintaining the thermal cracking temperature, respectively. The utilization of catalysts has been an interesting focus; however, it has not yet been fruitful as many of the developed catalysts deactivate rapidly, and they are expensive or toxic. The motives of the current study are to review tar formation characteristics and trends on catalytic conversion. In addition, the study elucidates the fascinating behaviour of metallic and oxides of the iron-based catalyst under different syngas composition (oxidizing and reducing environments). The behaviours of the iron-based catalyst indicate its fundamental role in developing a catalyst for tar cracking with respect to less toxic, inexpensive, abundant, and regenerable alternatives

Widespread colonisation of Tanzanian catchments by introduced Oreochromis tilapia fishes: the legacy from decades of deliberate introduction

From the 1950s onwards, programmes to promote aquaculture and improve capture fisheries in East Africa have relied heavily on the promise held by introduced species. In Tanzania these introductions have been poorly documented. Here we report the findings of surveys of inland water bodies across Tanzania between 2011 and 2017 that clarify distributions of tilapiine cichlids of the genus Oreochromis. We identified Oreochromis from 123 sampling locations, including 14 taxa restricted to their native range and three species that have established populations beyond their native range. Of these three species, the only exotic species found was blue-spotted tilapia (Oreochromis leucostictus), while Nile tilapia (Oreochromis niloticus) and Singida tilapia (Oreochromis esculentus), which are both naturally found within the country of Tanzania, have been translocated beyond their native range. Using our records, we developed models of suitable habitat for the introduced species based on recent (1960–1990) and projected (2050, 2070) East African climate. These models indicated that presence of suitable habitat for these introduced species will persist and potentially expand across the region. The clarification of distributions provided here can help inform the monitoring and management of biodiversity, and inform policy related to the future role of introduced species in fisheries and aquaculture