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Da Silva, Izael

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Author: Da Silva, I. P ×

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    Use of solar concentrators for steam generation in industrial processes
    Da Silva, Izael; Da Silva, I. P; Okure, M
    Steam plays a substantial role in several industrial processes and is usually required in significant amounts to enable continuous production in beverages, dairies, flower farms, and many other agro-processing industries. Currently, the predominant method for steam generation in such industries is by using furnace oil to fire boilers that generate the required steam. This technique has negative environmental and economical consequences, whose impact is felt especially in developing countries like Uganda. In order to become competitive both locally and internationally, there is need to develop a sustainable technology, which is economically viable, environmentally friendly and provides the steam requirements appropriate for the various industrial applications mentioned above. The solar technology will utilize the considerably high insolation of Uganda which is approximated at 157kWh/m2 per month. This insolation is ten times more than that in London and seven times more than that in Vienna or Berlin. This paper reports on the development of a solar water heater concentrator for use in industries in Uganda. The issues tackled in this work are: different reflective materials, heating fluids, the combination of hybrid flat collector-cumconcentrator, solar tracking possibilities versus static ones, heat power measurement and parabolic design, and economical viability study It is expected that this study, done in cooperation with Solar Construct (U), will create capacity to have this type of solar-powered water heater produced and utilized in Uganda to partially replace furnace oil boilers as a more economical alternative
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    Energy for social transformation : a study of the West Nile region of Uganda
    (Domestic use of energy conference, ) Da Silva, Izael; Tickodri-Togboa, S.S; Da Silva, I. P
    This Paper presents the results of technical, financial, environmental and management feasibility studies into the provision of reliable, sustainable and environmentally-friendly supply of electricity to the north-west corner of Uganda, called the West Nile Region – a region that is highly populated by comparison with the average population densities of the country and whose location is of both strategic and economic importance in that it serves as a gateway to the Democratic Republic of Congo and the Central African Republic in the west and to the south of Sudan in the north. The study examines various possible options for supply of electricity to the region and concludes that the optimal mode is through micro/mini-hydro power plants to be built on the 19 potential sites along nine principal rivers that drain the five districts comprising the region. It presents the current situation of supply of electricity in the region. This is followed with a detailed study for the implementation of the site at Olewa – the site nearest and with sufficient capacity to supply the current largest load centre in the area, which are the Arua Municipality and its environs. Due to the close similarities amongst those sites, it is argued that the data and findings pertaining to the Olewa one can easily be extended to the others, which thus makes this study beneficial and of direct relevance for the whole region. The paper then proceeds to discuss some of the foreseeable transformations that are likely to emanate from availability of adequate and reliable electricity supply in the region and ends with concluding remarks and recommendations.
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    An M&E mobile based application for Pico PV lighting solutions for the “Kerosene Free Kenya” project
    (Small PV-Applications Rural, ) Da Silva, Izael; Da Silva, I. P; Ronoh, G.; Maina, D. N
    This paper describes the use of a mobile based application used as a Monitoring and Evaluation (M&E) tool to a pilot project supported by the National Council for Science and Technology of Kenya (NCST) which seeks to research best practices and lessons learned in the dissemination of Pico PV systems to rural households in Kenya. In order to overcome the affordability barrier a microfinance institution (MFI) was brought into the system, to properly handle the challenge of access to finance while Lighting Africa will provide standards for the products to be distributed. Many of such pilot system have been used in practically all countries of East Africa. The novelty of the present one is the use of an Unstructured Supplementary Service Data (USSD) mobile based tool to collect and transmit data. This will make the analysis of the product quality, user experience and faults much simpler and given the two ways relationship between the researchers and the users, consumer satisfaction and product improvement is envisaged to happen in a to date unprecedented manner. As the clients are distributed in a known geographical region, the researchers have provided for the training of technicians to handle repairs and battery replacement locally. As the duration of the project is 2 years, it is expected that the follow up of product performance and life span will be measured way beyond its payback period.
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    Modeling the profitability of power production from short-rotation woody crops in Sub-Saharan Africa
    (2012) Da Silva, I. P; Da Silva, Izael
    Increasing electricity supply in Sub-Saharan Africa is a prerequisite to enable economic development and reduce poverty. Renewable sources such as wood-fueled power plants are being promoted for social, environmental and economic reasons. We analyzed an economic model of a vertically integrated system of short-rotation woody crops (SRWC) plantations coupled with a combined heat and power (CHP) plant under Sub-Saharan African conditions. We analyzed a 5 MW (electric) base-case scenario under Ugandan conditions with a 2870 ha Eucalyptus grandis plantation and a productivity of 12 t ha 1 y 1 (oven dry basis) under a 5-year rotation. Plant construction and maintenance constituted 27% and 41% of total costs, respectively. Plantation productivity, carbon credit sales as well as land, fuel, labor & transport costs played an economic minor role. Highly influential variables included plant efficiency & construction costs, plantation design (spacing and rotation length) and harvest technologies. We conclude that growing 12e24 t ha 1 y 1 at a five-year rotation can produce IRR’s of 16 and 19% over 30-years, respectively. Reducing rotation length significantly reduced short-term financial risk related to frontloaded costs and relatively late revenues from electricity sales. Long-term feed-in tariffs and availability of a heat market played a significant economic role. The base-case scenario’s 30-year IRR dropped from 16% to 9% when a heat market was absent. Results suggest a leveling-off of economies-of-scale effects above 20MW(electric) installations. Implementation-related research needs for pilot activities should focus on SRWC productivity and energy life cycle analysis
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    Swer (single wire earth return) systems user applications – optimizing the use of this cost–effective electrification tool with suitable end-user applications' – the Ugandan case
    Da Silva, Izael; Da Silva, I. P; Simonis, P.; Roeber, J.; Turyahikayo, G.; Merwe, V.
    The access to electricity is becoming a major demand in all societies in the developing countries. The declared aim of Uganda’s Ministry of Energy and Mineral Development to increase the access to electricity to 10% of Uganda’s population implies the electrification of 40,000 rural household per year, bringing ‘power to the people’. Access to electricity is directly associated with higher levels of living conditions. Individual households, (rural and urban) when provided with electricity have better conditions of cleanliness, health and self-empowerment. Key institutions in society (private, governmental, non-governmental, parastatal) also require electricity to enhance the effectiveness and efficiency of their operations and programmes. The introduction of SWER (Single Wire Earth Return) technology has significant merits regarding cost effectiveness to supply electricity to remote areas. This is especially the case where a strong backbone reticulation system is in place to supply high load centres (such as mines and larger towns, water pumping installations). Additional rural settlements and low demand settlements with clinics, schools, hostels, small borehole pumping installations can be adequately supplied with SWER (Single Wire Earth Return) technology.
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    Designing decentralized small-scale bioenergy systems based on short rotation coppice for rural poverty alleviation
    Da Silva, Izael; Buchholz, T; Volk, T; Tennigkeitb, T; Da Silva, I. P
    Access to electricity is crucial for the attainment of the Millennium Development Goals of poverty reduction and environmental sustainability. In East Africa, increasing environmental degradation and modern energy supply are a major obstacle to sustainable rural development. Small-scale bioenergy systems can supply clean, renewable and affordable energy to rural communities while at the same time creating new job opportunities and having beneficial impacts on natural resources especially when fed from Short Rotation Coppice (SRC). However, bioenergy systems are complex because their three components feedstock supply, conversion technology and energy allocation are influenced by environmental factors simultaneously with economic and social factors. Assessing these factors and their interdependence is essential to determine the project’s contribution to sustainable development as failure of one component can lead to failure of the entire system. Decision Support Tools (DST) structure the collection and evaluation of quantitative and qualitative information about social, economic and environmental impacts at scales ranging from local to national level. DSTs enable transparent and informed decisions even when limited information is available and many participants with different expertise and interests are involved to consider all relevant criteria. This paper introduces an approach to develop a DST assessing sustainability of bioenergy systems.
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    A heuristic model for planning of single wire earth return power distribution systems
    (Power and Energy Systems and Applications, PESA, ) Da Silva, Izael; Da Silva, I. P; Bakkabulindi, G.; Mohammad, R. H.; Amelin, M.; Lugujjo, E.
    The planning of distribution networks with earth return is highly dependent on the ground's electrical properties. This study incorporates a load flow algorithm for Single Wire Earth Return (SWER) networks into the planning of such systems. The earth's variable conductive properties are modelled into the load flow algorithm and the model considers load growth over different time periods. It includes optimal conductor selection for the SWER system and can also be used to forecast when an initially selected conductor will need to be upgraded. The planning procedure is based on indices derived through an iterative heuristic process that aims to minimize losses and investment costs subject to load flow constraints. A case study in Uganda is used to test the model's practical application.
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    Rural Electrification using off-grid Solar PV powered Energy Kiosks
    (Ostbayerisches Technologie-Transfer-Institute.V. (OTTI), ) Da Silva, Izael; Da Silva, I. P; Njuguna, P. M; Njogu, M.
    Access to electricity in rural Kenya and other developing African countries is low because historically power utilities employ a centralized grid system of electrification that is expensive to expand and would take decades to reach the majority in these areas thus opening opportunity to decentralized solutions. An off grid solar PV powered Energy Kiosk is one of the possible models of electrification which makes commercially sense in the task of bringing energy to isolated communities. Using data and experience from a pilot energy kiosk installed in Kenya, this paper shows how this facility ably electrifies isolated rural communities and points out how it could be replicated in the rest of developing Africa. Using PV which is a proved technology, the target is to avail electricity for basic domestic use and enterprises in rural communities.