http://repository.tml.nul.ls:80/handle/123456789/172 2006-01-02T11:09:52Z http://repository.tml.nul.ls:80/handle/123456789/1476 Energy Supply Management System for Lesotho: User Interactive System Mololo, Tsepo Phineas There is inadequate energy data in Lesotho due to lack of data collection tools that would assist in collecting and storing data from supply through transformation to final use of each energy form. This report describes a development of a full web-based system that captures and stores energy products in database from various supply sources using Personal Home Page (PHP) programming language. This system is user interactive and allows specified users to insert and/or retrieve energy products from the database while other users can register into the system to view, query or fetch as well as download stored energy products data and system generated energy commodity account (ECA) and energy balance (EB) for a specified year. From the 2017 and 2018 energy data that has been inputted into the Energy Supply Management System (ESMS), an ECA and EB reports are generated for the energy supply part which is where the system’s emphasis is on. The report provides analysis on Lesotho’s energy supply mix which is mainly from biomass with 73% of the total supply for both 2017 and 2018, with almost no traces of renewable energy penetration for both years. The supply of petroleum fuel constitutes 19% and 18% for 2017 and 2018 respectively which indicates a significant contribution to the greenhouse gases (GHG) emissions to the environment. It further gives analysis from the system generated EB on Lesotho’s self-reliance on energy supply which shows 75% and 76% for 2017 and 2018 respectively from indigenous production mainly covered by unsustainable biomass used inefficiently by major population of Lesotho. The major portion of energy supply is from imports of electricity from Eskom and EDM, coal and coal products, petroleum fuel and liquefied petroleum gas from South African mines and refineries respectively which indicates Lesotho’s reliance on imports and hence less security of energy supply. 2020-05-01T00:00:00Z http://repository.tml.nul.ls:80/handle/123456789/1475 Development of charcoal briquettes using Sehalahala (Seriphium plumosum and Felicia filifolia) Thabane, Kanono Introduction: Production of charcoal briquettes using invasive shrubs found on Lesotho’s rangelands can provide alternative sustainable biomass energy for household heating and cooking applications in rural Lesotho. Objectives: To develop briquettes using the two species of Sehalahala (Seriphium plumosum and Felicia filifolia) and evaluate the performance properties of charcoal briquettes made from the two shrubs. Methods: Sehalahala feedstock was harvested and dried for five days to reduce the moisture content. Dried materials were cut and carbonised using a 200L steel drum. Wheat and clay binders were added at 5% (w/w) with charcoal powder and mixed together. Puck shaped briquettes were developed using a car jack driven briquetting machine. Four treatments (2 species and 2 binders) were developed and compared with a briquette purchased from the local supermarket for benchmarking. Proximate analysis was conducted using ASTM standards. Caloric value (MJ/Kg) was calculated using an empirical formula. Ultimate analysis was undertaken using a LECO CHNS 628 Determinator. Results: The mean percentage value of the four manufactured briquettes for the respective parameters evaluated were found to be as follows: moisture content (6.83 ± 2.72) m %,volatile matter content (30.53 ± 5.93) m %, ash content (3.77 ± 1.10) m %, fixed carbon (58.88 ± 6.51) m %, and higher heating value (25.66 ± 1.28) MJ/kg. In addition, the results indicated that the clay binder yields higher calorific value compared to the boild wheat flour suspention mix. Results of the ultimate analysis showed total carbon (35.14 ± 4.13) %, total nitrogen (1.01 ± 0.20) %, hydrogen (2.13± 0.26)% and sulphur (0.34 ± 0.08) %. Conclusion: Based on the results, it can be concluded that Sehalahala is suitable for production of bio-char briquettes. The newly produced briquettes have a higher energy content, less indoor air pollution and burns longer than traditional biomass (cow dung, agro-residues, shrubs, wood, etc) used in rural Lesotho for cooking and laughing applications. However, the results also indicate an opportunity for optimising production methods in order to achieve better results for mass production. 2020-08-01T00:00:00Z http://repository.tml.nul.ls:80/handle/123456789/1474 Development of solar radiation database and its integration into solar process applications in Lesotho Bulane, Lebohang Solar energy is a viable alternative source of energy for socio-development of a developing country like Lesotho. Investment in solar process applications, requires a accurate solar radiation data for the successful implementation of solar process projects. However, in Lesotho measured solar radiation datasets are not sufficient both temporally and spatially as there are only seven solar radiation measuring sites, two of which are not reliably operational. This study solves the problem of the scarcity of solar radiation data in Lesotho, by developing a solar radiation database for the country. It has a primary objective of developing an accurate solar radiation database for Lesotho. This is achieved by merging ground measured solar radiation data with satellite – derived solar radiation data. The merged data is complimented by solar radiation data derived from sunshine duration data. Merging solar radiation datasets is important because ground measured data are sparsely distributed and cannot be interpolated accurately to represent solar radiation at any location. Although satellite – derived datasets are spatially continuous, they are not accurate as they are inferred from extra- terrestrial solar radiation modified with atmospheric models. As a result, each of the databases cannot be relied up unilaterally. Measured ground data is from five stations and sunshine duration derived solar radiation is form twelve stations. The improved database is validated using a leave one out cross validation technique. Its reliability in estimating ground solar radiation is tested by relative bias error (rBE), relative mean bias error (rMBE) and normalized root mean square error (NRMSE). Results show that the database is credible as it has a maximum error of 2.7 % which is comparable to other studies of similar nature in Africa. An interpolation tool, increases the accuracy and reliability of interpolated solar radiation as compared to manual reading of data from solar radiation maps. It has an accuracy of 99.54%. The improved database and interpolation tool can confidently be used in any solar application process design and sizing in the country. 2020-05-01T00:00:00Z http://repository.tml.nul.ls:80/handle/123456789/1473 Determination of Cost-Reflective Feed-in Tariff for Grid Connected Solar PV Systems in Lesotho Kokome, Limpho Lesotho needs a feed-in tariff policy that can help accelerate integration of renewable energy in its electricity grid. In this study a method to determine the feed-in tariff for grid connected solar Photovoltaic (PV) systems was developed. The necessity to set different tariffs for different locations in terms of the solar PV array yield 𝑌, and different tariffs for different installed capacities were examined. Location specific tariffs were examined because given a particular solar module, the array yield 𝑌 could vary with location because of different ambient temperature and radiation, while size specific tariffs were examined because solar PV systems have different specific costs for different system sizes. In order to determine the cost reflective feed-in tariff, the Levelized Cost of Electricity (LCOE) was used as the objective function. With this approach the feed-in tariff was set as the price for selling electricity that is reasonably above the unit cost of production. A custom spreadsheet model was used to calculate the solar PV array yield 𝑌 over Lesotho. This array yield was used to divide Lesotho into two regions, low yield regions, and high yield regions. Representative systems were chosen and the feed-in tariff for different solar PV installed capacities in both regions were determined. The study found that the feed-in tariff varies with location and system size as follows; System Category FiT ($/kWh) Low Array Yield Region High Array Yield Region 30 kWp Roof Mount 0.1778 0.1616 500 kWp Roof Mount 0.1597 0.1451 30 kWp Ground Mount 0.1740 0.1581 500 kWp Groun Mount 0.1453 0.1321 10 000 kWp Ground Mount 0.1138 0.1034 The study recommends a feed-in tariff that is both location and size specific. The feed-in tariff depends on duration of the tariff with shorter periods resulting in higher feed-in tariff. A 20-year duration of the feed-in tariff is therefore recommended by this study. The method used in this study to determine the feed-in tariff included the impact of inflation in the analysis and therefore a fixed feed-in tariff (that is not indexed to inflation) is recommended. The energy regulator, and theministry responsible for energy policy setting can make use of this study in setting out feed-in tariff policy. 2020-05-01T00:00:00Z