Journals
Home > Publications > Journals
Journal Title
Year
Authors
Journal Link
Design and Economic Analysis of a Solar Thermal Pre-Cooling System for Agro-Cold Chain in Lesotho
The agricultural sector in Lesotho grapples with significant challenges regarding post-harvest losses. Given that 40% of all agricultural products require cold storage, food quality is compromised due to lack of cold storage to extract the heat from exposure to high field temperatures after harvest. This research proposes a solar thermal cooling system tailored to the specific needs of preserving fresh agricultural produce, leveraging Lesotho’s abundant solar energy resources. Through TRNSYS simulation and MATLAB economic analysis, optimal system parameters are determined, ensuring both technical efficiency and financial viability.
The outcomes indicate that the proposed absorption solar thermal cooling system, incorporating evacuated tube collectors and an auxiliary boiler, effectively manages a cooling load of 7.318 kW, preserving fresh vegetables at 6.1°C. The optimized design features a chiller with a Coefficient of Performance of 0.8, a collector area of 12 m², and a hot storage volume of 0.2 m³, maximizing solar energy utilization. Importantly, economic metrics such as Levelized Cost of Energy ($0.085/kWh), Net Present Value ($9,200), Discounted Payback Period (12 years), and Savings to Investment Ratio (achieving 1 in year 13) demonstrate the financial feasibility and profitability of the system.
These findings underscore the potential of solar thermal cooling as a promising investment option for addressing refrigeration needs in Lesotho, offering a sustainable solution to mitigate post-harvest losses and enhance economic performance in the agricultural sector.
2024
2024
- Mpho Yengane
- Sebota Mokeke
- Moeketsi Mpholo
Community imaginaries, participation and acceptance of renewable energy projects–substituting the quicksand of development with rocky fundamentals
Community participation could contribute to sustaining energy projects, however some projects underestimate the value of meaningful project host communities’ involvement in decision-making. Rural community energy development projects in Lesotho often assume a top-down development-driven approach void of communities’ perspectives and desires. This study investigates opportunities Lesotho’s renewable energy projects, either led by communities or the government, provide. The authors draw from qualitative research to examine two cases, Semonkong and Motete’s participatory approaches. This study determined the magnitude of community participation in the two projects, from their initiation to the level of community participation in decision-making and implementation. The findings posit that community participation in both projects differs from minimal to no participation. They further revealed a blurry picture of community acceptance of the project where participation was relatively lower, thus bringing project sustainability into question. The Lesotho Electric Company deprived the Semonkong community the opportunity to participate in the decisions of the Semonkong mini-grid. In contrast, the Motete project consortium allowed a modicum of community participation hence higher social acceptance prospects. The study revealed that tensions, conflicts, and protests are implications associated with lack of community participation in the project of Semonkong. The sustainability of projects is dependent on the extent of the host communities’ involvement, acceptance, and trust. This study recommends community engagement for hammering and forging project acceptability and sustainability.
2024
2024
- Seroala Tsoeu-Ntokoane
- Thuso Donald Mosabala
- Moeketsi Kali
- Xavier Lemaire
Community engagement and sustainability: Two cases of implementation of mini-grids in Lesotho
Based on a survey of two Lesotho communities, this study assessed the type of governance of energy that favours the emergence of energy democracy or community energy. It established that the centralized energy governance of Semonkong seems less effective in solving conflicts compared to the decentralized energy governance of Ha-Makebe. Poor communication and lack of will to respond to community needs caused dissatisfaction and misunderstanding towards the centralized energy project. The study found that the decentralized energy project was more likely to be sustainable because it was characterized by community participation and engagement. The findings also revealed that the satisfaction of energy consumers results from a consistent supply of energy accompanied by responsiveness to community needs as opposed to a cheap inconsistent electricity supply. The implications are that the Semonkong plant's sustainability is at risk, and the project may collapse unless the Government of Lesotho, in the short term, engages with the community regarding its concerns.
2023
2023
- Seroala Tsoeu-Ntokoane
- Moeketsi Kali
- Xavier Lemaire
Energy democracy in Lesotho: Prioritising the participation of rural citizens
When projects are exclusionary, they are bound to fail because they are void of a collective sense of belonging and ownership. The government of Lesotho has been stridently pursuing renewable energy initiatives to augment the hamstrung monopoly provider and increasing user demand in energy provision. Based on content analysis, this study revealed that the government’s troubles in managing grid and off-grid energy provision in the country result from its exclusionary technical-economic strategy that subverts citizen participation in decision-making. This study contends that power without a people is not a realistic option. This calls for an energy transition from fossil fuels to renewable energy in Lesotho. It proposes that operationalising energy democracy is not only transformative but also a sustainable future. Widening civic space in the energy sector and adopting a participatory approach will likely transform the status quo by creating jobs and ensuring environmental justice.
2022
2022
- Seroala Tsoeu-Ntokoane
- Moeketsi Kali
- Xavier Lemaire
An Optimization Approach for the Economic Dispatch Incorporating Renewable Energy Resources into Lesotho Power Sources Portfolio
Electricity demand in Lesotho has surpassed the main domestic generation of 72-MW hydropower station with 59% capacity deficit currently met by imports from South Africa and Mozambique through costly fixed bilateral contracts. With the abundant renewable energy sources in Lesotho, independent power producers could be incentivized to erect solar PV plants and wind farms to increase local energy security at lower cost and diversify utility's power mix. This article develops a power dispatching approach that prioritizes solar PV and wind generators to aid hydropower station meet demand and only be backed by imports. It uses the Monte Carlo approach to simulate generation adequacy analysis in order to establish monthly average expected demand not supplied (EDNS) and loss of load probability (LOLP) for the baseline case and three dispatch scenarios. According to the analysis, the EDNS for all simulated scenarios never drops to 0 MW, while the LOLP only reaches a minimum of 52% for the scenario with all local renewable energy generators combined. Furthermore, main grid energy imports can be minimized by 22.3% with the introduction of 50-MW solar PV and by 40.2% for 58-MW wind farms. A 59.7% minimization can be obtained by combining solar PV at 50-MW, wind farms at 58-MW and MHP at 72-MW. These introductions would lead to subsequent reductions in power procurement costs of about 6.2% for solar PV alone and 1.11% for both solar PV and wind. However, the inclusion of wind energy alone would lead to slight cost increase of about 0.6%.
2023
2023
- Thato Nchakha Rateele
- Leboli Z. Thamae
Lesotho Electricity Demand Profile from 2010 to 2030
This study undertook a 2010 to 2030 electricity demand profile for Lesotho, with 2010 used as the base year. The demand forecast was modelled using the International Atomic Energy Agency Model for Analysis of Energy Demand, largely because of its proven ability to accurately forecast demand in developing economies based on socio-economic, technology and demography variables. The model correlates well with the actual data, where data exists, and predicts that by 2030 Lesotho will achieve a national electrification rate of 54.2%, with 95% for urban households and 14% for rural households, up from 19.4%, 54.1% and 1.8% respectively in the base year. Moreover, in the same period, the forecast for the most likely scenario gives the following results: the maximum demand will increase to 211 MW from 121 MW; the annual average household energy consumption will continue its decline to 1 009 kWh/household from 1 998 kWh/household; and the total consumption will increase to 1 128 284 MWh from 614 868 MWh. The overall low growth rate is attributed to the consistently declining average household consumption that is contrary to international norms. The forecast results gave a root mean square percentage error of 1.5% and mean absolute percentage error of 1.3%, which implied good correlation with the actual data and, hence, confidence in the accuracy of the results.
2021
2021
- M. Mpholo
- M. Mothala
- L. Mohasoa
- D. Eager
- R. Thamae
- T. Molapo
- T. Jardine
The Impact of Intermittent Renewable Energy Generators on Lesotho National Electricity Grid
Utility-scale integration of solar photovoltaic (PV) and wind farms has gained momentum as countries pursue sustainable power systems. Increased penetration of solar PV and wind alters the operation of power grids as they have different electrical properties from conventional power plants. The paper assesses the dynamic and steady state impacts of intermittent (variable) renewable energy generators (IREGs) on the Lesotho power grid. Maximum allowable penetration of both solar PV and wind generators were determined for Ha-Ramarothole and Letseng sub-stations, respectively. Dynamic impact studies were performed by applying the short circuit fault at the bus bar with the least critical clearing time (CCT) and observing voltage, frequency and rotor angle as the renewable energy capacity was varied. Steady state voltage analysis was performed based on the hourly load of 2018 and generation of both IREGs and Muela Hydropower. Voltage, frequency and rotor angle stability were evaluated against the Grid Code of Lesotho. The impact studies were done using DigSILENT PowerFactory software. Maximum allowable penetrations for solar PV was about 19% at Ramarothole substation while for wind it was found to be 27% at Letseng substation. Simulations revealed that increased penetration of the IREGs led to grid instability. The solar farm penetration of 36 MW connected at 132 kV resulted in grid instability mainly from the rotor angle instability while the wind farm penetration of 52 MW connected at 88 kV resulted from an overvoltage of 1.051 p.u. at the neighboring 33 kV substation of Tlokoeng.
2021
2021
- Sebota Mokeke
- Leboli Z. Thamae
Determination of the Lifeline Electricity Tariff for Lesotho
Lesotho has a poverty rate above 50%, this renders a bulk of households connected to the grid unable to purchase enough energy to cover the essential basic needs at the current tariffs. This is supported by the declining average household consumption reported by Lesotho Electricity Company (LEC) despite an increasing customer base. Even more crucial, for low income countries, tariff levels should balance social stability, affordability, fairness, energy efficiency as well as cost recovery especially because the poor make up the majority of the population. Based on the poverty line, a lifeline tariff of 0.5 to 0.6 Maloti(M)/kWh (2017 tariffs) for a threshold of up to 30kWh/month is proposed which is 35%–42% lower than the current domestic tariff of 1.424 M/kWh. The standard domestic tariff will need to increase to 1.856 M/kWh to allow for cross-subsidisation and hence maintain the financial standing of the utility company. The threshold capacity is based on the observation that in 2016,around 30% of grid connected households consumed less than 30 kWh/month which is enough electricity to cover the basic needs of an average household. Hence, an increasing block tariff (IBT) approach is proposed such that the first 30 kWh/month are set at a lifeline tariff and any excess is charged at a standard rate which is set such that it cross-subsidises the lifeline tariff.
2020
2020
- Matsoso Mothala
- Lebohang Mohasoa
- Dan Eager
- Retselisitsoe Thamae
- Tsita Molapo
- Tom Jardine
Long-Term Austral Summer Wind Speed Trends Over Southern Africa
A low-cost flat plate solar energy collector prototype was designed, constructed and tested for functional performance. The aim of the investigation was to develop functionally-sound and low- cost flat plate solar energy collector suitable for use by low-income groups, including dwellers of remote rural areas, who are generally poor. Hence, apart from functional performance, the device had to be low-cost, simple and easy-to- maintain. Low-cost was achieved through the use of cheap and locally available materials — raw sheep wool, ordinary window pane-glass, and galvanized plate sheet — as substitutes to the more expensive conventional materials. Effectively, it is estimated that the selling price of this system would be at least30% cheaper than what is currently on the market. The parameters measured and used to determine the device performance efficiency were temperature and solar radiation. The collector efficiency during peak sunshine period (that is, 11:00 to 14:00 hours) varied from a maximum of 25% (at 11:00 hours) to a minimum of 20% (at 14:00 hours). Observably the efficiency range is much lower than those of conventional systems, and there is much room for improvement on the design and/or construction materials. However, ongoing measurements have already shown that the system is capable of sustaining water temperatures above 40°C against ambient temperature of as low as 10°C, which is acceptable for bathing and other household chores
2017
2017
- Teboho Nchaba
- Moeketsi Mpholo
- Chris Lennard
Prediction of Solar Irradiation Using Quantum Support Vector Machine Learning Algorithm
Classical machine learning, which is at the intersection of artificial intelligence and statistics, investigates and formulates algorithms which can be used to discover patterns in the given data and also make some forecasts based on the given data. Classical machine learning has its quantum part, which is known as quantum machine learning (QML). QML, which is a field of quantum computing, uses some of the quantum mechanical principles and concepts which include superposition, entanglement and quantum adiabatic theorem to assess the data and make some forecasts based on the data. At the present moment, research in QML has taken two main approaches. The first approach involves implementing the computationally expensive subroutines of classical machine learning algorithms on a quantum computer. The second approach concerns using classical machine learning algorithms on a quantum information, to speed up performance of the algorithms. The work presented in this manuscript proposes a quantum support vector algorithm that can be used to forecast solar irradiation. The novelty of this work is in using quantum mechanical principles for application in machine learning. Python programming language was used to simulate the performance of the proposed algorithm on a classical computer. Simulation results that were obtained show the usefulness of this algorithm for predicting solar irradiation.
2016
2016
- Makhamisa Senekane
- Benedict Molibeli Taele
Low-Cost Small Scale Parabolic Trough Collector Design for Manufacturing and Deployment in Africa
Concentrating Solar Power is expanding its deployment on the African subcontinent, highlighting the importance of efforts to indigenize manufacturing of this technology to increase local content and therefore local economic benefits of these projects. In this study a design for manufacturing (DFM) exercise was conducted to create a locally produced parabolic trough collector (the G4 PTC). All parts were sourced orfabricated at a production facility in Lesotho, and several examples of the design were prototyped and tested with collaborators in the Government of Lesotho’s Appropriate Technology Services division and the National Universityof Lesotho. Optical and thermal performance was simulated and experimentally validated, and pedagogical pre-commercial versions of the PTC have been distributed to higher education partners in Lesotho and Europe. The cost to produce the PTC is 180 USD/m 2 for a locally manufactured heat collection element (HCE) capable of sustaining 250C operation at~65% efficiency. A version with an imported evacuated HCE can operate at 300°C with 70% efficiency. Economically relevant applications for this locally produced PTC include industrial process heat and distributed generation scenarios where cogeneration is required.
2016
2016
- Matthew Orosz
- Paul Mathaha
- Anadola Tsiu
- Lengeta Mabea
- Marcel Ntee
- Makoanyane Khakanyo
- Tamer Teker
- Jordan Stephens
- Amy Mueller
Electricity Consumption and Economic Growth in Lesotho
The paper analyses the causal relationship between electricity consumption and economic growth in Lesotho for the period 1972–2011 by using autoregressive distributed lag bounds testing approach of cointegration. The results indicate that there is a stable long-term relationship between electricity consumption and economic growth, with the direction of causality running from economic growth to electricity consumption. These findings support the conservation hypothesis and imply that economic growth in Lesotho spurs electricity consumption, but not the other way round. Therefore, various energy conservation measures aimed at reducing electricity consumption and waste in Lesotho may not have a negative impact on economic growth.
2016
2016
- Sekantsi, L.P
- Retselisitsoe Isaiah Thamae
Yield and Performance Analysis of the First Grid-Connected Solar Farm at Moshoeshoe I International Airport, Lesotho
The performance of a newly installed 281 kWpfirst grid-connected photovoltaic solar farm in Lesotho is evaluated against the basic parameters stated in the International Electro-Technical Commission (IEC) Standard 61724 and a number of other studies. The performance parameters selected are those that mainly indicate the suitability of a site for solar power development. Using normalised values, a brief comparison with other farms across the globe is made to assess the relative performance of the farm. The results show that its performance is satisfactory, with a weighted performance ratio of 0.70 compared to the global average of 0.70e0.80 for sufficiently well performing farms. However, the performance could be improved with improved operational monitoring of the farm. Additional performance parameters are assessed relative to the standard and the farms in other countries, such as capture and system losses, system efficiencies, and capacity factors, are above the thresholds for satisfactory performance. Measurements at the site show a high solar energy resource in the range of 4.0e7.2 kWh/m 2/day. The results show that the area is suitable for grid connected photovoltaic systems.
2015
2015
- Moeketsi Mpholo
- Molebatsi Monese
- Teboho Nchaba
Waste Generation and Management in Lesotho and Waste to Clay Brick Recycling: A Review
Waste management remains a matter of concern even in the most industrialized countries. The symbiotic relationship between industrialization and population growth on one hand and waste generation on the other hand, is undeniable. In developing counties the scourge of waste management has reached endemic levels; and only innovative and economic ways of waste management can serve as a sustainable solution. Municipalities and local authorities in developing countries spent in the order of 30% of their budgets on waste management, yet their efforts yield no salient fruits as random dumping, burning and illegal land filling remain dominant. The accompanying health and environmental hazards can never be over-emphasized. Research works, past and present, continue to reveal the possibility of turning waste into valuable raw material inputs to suitably identified products and processes. This paper focuses on reviewing the waste management situation in Lesotho, using Maseru city as base line, and results of research works on incorporation of waste materials in clay brick manufacture. Clay brick making is a key industry in Lesotho accompanying environmental issues notwithstanding. Suffice to say, a deliberate attempt has been made to streamline the attention towards those waste materials known to be available or generate in Lesotho in significantly large quantities.
2015
2015
- I. Hapazari
- V. Ntuli
- B.M. Taele
Dynamics of Electricity Demand in Lesotho: A Kalman Filter Approach
This study provides an empirical analysis of the time-varying price and income elasticities of electricity demand in Lesotho for the period 1995-2012 using the Kalman filter approach. The results reveal that economic growth has been one of the main drivers of electricity consumption in Lesotho while electricity prices are found to play a less significant role since they are monopoly-driven and relatively low when compared to international standards. These findings imply that increases in electricity prices in Lesotho might not have a significant impact on consumption in the short-run. However, if the real electricity prices become too high over time, consumers might change their behavior and sensitivity to price and hence, energy policymakers will need to reconsider their impact in the long-run. Furthermore, several exogenous shocks seem to have affected the sensitivity of electricity demand during the period prior to regulation, which made individuals, businesses and agencies to be more sensitive to electricity costs. On the other hand, the period after regulation has been characterized by more stable and declining sensitivity of electricity demand. Therefore, factors such as regulation and changes in the country’s economic activities appear to have affected both price and income elasticities of electricity demand in Lesotho.
2015
2015
- Retselisitsoe I. Thamae
- Leboli Zak Thamae
- Thimothy Molefi Thamae
Assessing a Decade of Regulatory Performance for the Lesotho Electricity Industry
Government-run electricity utilities around the world have been subjected to reform and regulation over the last two decades in an effort to introduce private investment and competition for reliable and affordable services in support of socio-economic development. Although extensive scholarly literature abounds with regard to experiences with restructuring and regulation in many developed economies, research on electricity-sector regulatory performance in small African developing countries like Lesotho is still rare. This article provides an empirical assessment of the three critical regulatory dimensions of governance, substance, and impact in order to evaluate the performance of electricity industry regulation in Lesotho for the period 2004-2014.
2015
2015
- Leboli Z.Thamae
- Retselisitsoe I.Thamae
- Thimothy M.Thamae
The Analysis of Demand for Electricity: The Case Study of Lesotho
2015
2015
- B. Honu
- Ch. Paramaiah
Efficacy of Cellulose Degrading MicrobialStrains on the Decomposition of Sewage Water Microalgae for the Production of Biogas
Sewage water microalgae are potential sources of feed stock for the production of biofuel. In this study, six treatment combinations of microbial strains (C, N1 and N2) in single and combined treatments were used in a 5L plastic container as anaerobic digester. The use of sewage water microalgae alone was used as a negative control; and a separate application of effective microorganisms (EM) were used for comparison. A volume of 3L sewage water suspension containing 300g of microalgae biomass were used in all plastic containers as a feedstock. All treatment applications including the control showed some activity of pressure development in each bag per treatment per cycle except the combined treatment of strain (C, N1, N2). Significant volume of biogas production (4-5L/300g)) and pressure development (517.80 and 544.35 Nm-2 was observed in the first cycle when using cellulose degrading microorganism (C) alone and the combined treatment with nitrogen fixing strain (N1), respectively.
2014
2014
- Sissay B. Mekbib
- Mosotho George
Construction and Performance Evaluation of a Low-Cost Flat-Plate Solar Energy Collector
A low-cost flat plate solar energy collector prototype was designed, constructed and tested for functional performance. The aim of the investigation was to develop functionally-sound and low- cost flat plate solar energy collector suitable for use by low-income groups, including dwellers of remote rural areas, who are generally poor. Hence, apart from functional performance, the device had to be low-cost, simple and easy-to- maintain. Low-cost was achieved through the use of cheap and locally available materials — raw sheep wool, ordinary window pane-glass, and galvanized plate sheet — as substitutes to the more expensive conventional materials. Effectively, it is estimated that the selling price of this system would be at least30% cheaper than what is currently on the market. The parameters measured and used to determine the device performance efficiency were temperature and solar radiation. The collector efficiency during peak sunshine period (that is, 11:00 to 14:00 hours) varied from a maximum of 25% (at 11:00 hours) to a minimum of 20% (at 14:00 hours). Observably the efficiency range is much lower than those of conventional systems, and there is much room for improvement on the design and/or construction materials. However, ongoing measurements have already shown that the system is capable of sustaining water temperatures above 40°C against ambient temperature of as low as 10°C, which is acceptable for bathing and other household chores.
2013
2013
- A. Tsiu
- Leboli Zak Thamae
- Innocent Hapazarii
- Benedict Molibeli
- Taele Benedict
Qualitative Assessment of Livestock Faeces and Sewage for Antibiotic Resistant Strains of E-Coli in Roma, Lesotho
Sewage water (SW) and fresh livestock faeces: Chicken (ChNF), Sheep (SF), and Cattle (CF) were taken randomly from the farm of the National University of Lesotho aseptically during the 2012 academic year. Twenty ml of sewage water or 20 grams of fresh animal faeces was dissolved in 80 ml of sterilized Ringer’s solution and serially diluted. A 0.1 ml of sample suspension at 10-4 dilution was spread plated on Nutrient Agar (NA) and Eosine Methyl Blue (EMB) and plates were incubated for 24-48h at 24 and 37°C, respectively. A disc diffusion method was used to test the reaction of selected strains of Enterobacteriaceaeto nine antibiotics. In total, 24 strains under Enterobacteriaceae were isolated from the respective sources and the number of each that were Escherichia coli, as confirmed by the biochemical tests were: SW (7 and 3); ChNF (5 and 3); SF (8 and 6) and CF (4 and 2). Thirteen E. coli strains fermented lactose and were Catalase positive, while only one E. colistrain from SW was non-lactose fermenter and Catalase negative. The lethal potencies, as number of isolates sensitive to the 9 antibiotics, ranked as: Colistin = Amikacin (24/24) > Kanamycin (23/24) > Chloramphenicol (22/24) > Cefotaxime (21/24) > Sulphafurazole (7/24) > Methicillin (1/24) > Penicillin G = Rifampicin (0/24). Sensitivity of the E. coli strains ranked as follows, Colistin = Amikacin = Kanamycin (14/14) > Chloramphenicol (13/14) > Cefotaxime (12/14) > Sulphafurazole (6/14) > Methicillin (1/14) > Penicillin G = Rifampicin (0/14). This result showed that the development of antibiotic resistant E. coli strains, which can pass through food chain to humans and other organisms if stringent control measures are not taken. Strict quarantine procedures have to be applied to control such potential health risks.
2013
2013
- Marole T. A
- Mekbib S.B
- Asita A. O
Wind Profile Assessment at Masitise and Sani in Lesotho for Potential Off-Grid Electricity Generation
Wind profile of two sites, one on the southern part of Lesotho, Masitise (30.367445 latitude, 27.669641 longitude, 1700 m altitude), and the other on the eastern part, Sani (29.58273 latitude, 29.287845longitude, 2900 m altitude), was analysed. Wind speed measurements for Masitise are taken at both 10 m and 25 m above ground level (a.g.l.) while for Sani anemometers are only placed at 9 m a.g.l. Both sites fall under the zero roughness class with bi-annual wind speed of 4.93 m/s and 5.50 m/s at 10 m and 9 m a.g.l., respectively. Moreover, their power densities are given by 121.6 W/m 2and 221.3 W/m 2.A model using Weibull distribution function is used to analyse the wind speed profile. The results compare well with the Wind Atlas Analysis and Application Program (WAsP). According to the global wind power classification, Masitise is a class 2 site while the windier site of Sani falls under class 3. Masitise may not be ideal for grid-connected electricity production but both sites have sufficient wind for off-grid electricity production. On average the turbines will be generating 80% and 75% of the time per annum at Masitise and Sani, respectively.
2012
2012
- Tebello Mathaba
- Mosuoe Letuma
Overview of Small Hydropower Development in Lesotho: Challenges and Prospects
Lesotho’s energy balance is largely dominated by combustible renewable resources. However, the country is well endowed with hydropower resources for the development of both large and small-scale hydropower projects. There are several challenges that have to be addressed in order to reap the full benefits of this resource. Some of the main challenges are high capital investment costs on projects of this nature and heavy siltation of small reservoirs due to extensive soil erosion. Various studies countrywide have identified 22 sites, with a combined potential of more than 20 MW to be suitable for small hydropower development. Of these sites, 4 have been developed to operational from mid 1980’s to early 1990’s. The plants were designed as hybrid system with diesel generator sets. Three of those plants operate on a river run-off system. It has been a general practice that the plants run on diesel for most periods of the year, which render them more expensive to run. Currently, 2 of the plants are mothballed as a result of the costs and other operational problems frequently encountered. This paper gives an overview of the setbacks that inhibit the smooth operation of small hydropower plants in Lesotho.
2012
2012
- I. Hapazari
- L Mokhuts’oane
- B.M.Taele
Grid Electrification Challenges, Photovoltaic Electrification Progress and Energy Sustainability in Lesotho
Lesotho's energy profile is characterized by a predominance of traditional biomass energy to meet the energy needs of the rural households and a heavy dependence on imported petroleum for the modern economic sector needs. As a result, the country faces challenges related to unsustainable use of traditional forms of biomass and exposure to high and unstable oil import prices. There are relatively abundant renewable energy resources in the form of hydro, solar and wind. The average daily solar radiation in Lesotho varies between 4.5 and 6.5 kWh/m2, with some areas in the South West averaging over 7 kWh/m2/day. Under the UNDP/GEF-supported Lesotho Renewable Energy-Based Rural Electrification (LREBRE) Project, a total of 5000 solar home systems (SHS) will be installed by 2012. Since the start of the project, a total of 1537 SHS with a capacity of 65 W have been installed, and an estimated 500 SHS have also been independently installed as a result of the project's influence. This paper examines the role of PV technologies in the sustainable development process, with particular reference to UNDP/GEF-LREBRE Lesotho PV project, and the extent to which this project is impacting on the PV industry. The paper also analyses national grid electrification and energy provision in rural areas and shows that the problem of rural electrification could be tackled by conventional and non-conventional means.
2012
2012
- L. Mokhutsoane
- I. Hapazari
- M. Senatla
- B.M.Taele
Velocity and Power Density Analysis of the Wind at Let’seng-La-Terae in Lesotho
The wind profile of Let'seng-la-Terae in Lesotho is analyzed using a 2-year data of 10-min averages. Wind velocity distribution data is estimated as a Weibull distribution using the Graphical Method and Method of Moments. The optimal Weibull parameters for the bi-annual data are obtained using the Method of Moments and the values of the dimensionless shape parameter, k ¼ 1.76, and the scale parameter, c ¼ 6.71 m/s at 10 m above ground level. The calculated air density at the site is 0.875 kg/m3 using the temperature and the pressure measurements. The data shows that the wind is prevalently from the West. The daily wind speed trends show that the interval between 5.00 am and 3.00 pm is the windiest for every month of the year. The months with the most and the least wind speeds are August and February, respectively. Let'seng-la-Terae is a class 4 wind energy site with a 95% confidence interval of both the bi-annual mean wind speed given by 5.97 0.07 m/s and the bi-annual mean power density given by 208.56 7.31 W/m2, both calculated at 10 m above the ground level. The typical turbines on the site are expected to operate 82.8 6.7% of the time. The results show that the site is ideal for large-scale electricity generation.
2012
2012
- Tebello Mathaba
- Mosuoe Letuma
- Moeketsi Mpholo
Assessment of the Impacts and Adaptive Capacity of the Machobane Farming System to Climate Change in Lesotho
2012
2012
- Olaleye, A. O
- Mokhothu, M. N
- Masia, J
- Sissay B. Mekbib
- Wondimu, T. G
Isolation, Thermostability and Enzyme Assay of Cellulose Degrading Microorganisms from Soils and Wastewater Samples at Roma, Lesotho
Bioremediation of cellulosic waste through enzymatic hydrolysis has the potential of reducing atmospheric and environmental pollution while concurrently producing valued-added bioproducts. Through this study, fifteen bacterial and fungal strains with cellulase activity were isolated from four different sampling sites using different cellulosic source media: CMC, methyl cellulose and laboratory kimwipes. Potential isolates were screened and identified using basic morphological and physiological characterization. Five strains: S1CBS1, S1CBS5, S1CFS6, S2CFS10 and S2CFS12 showed high cellulase activity at 60ºC for short period (24-36h) of incubation while strain S1CFS3 exhibited high cellulase activity on all carbon sources. The largest clear zone formation (32mm) was exhibited on CMC carbon source. Synergistic activity of isolates showed an improved cellulase activity with high concentration of reducing sugars in the first 48-72 hours and decreased significantly upon further incubation.
2012
2012
- Pakane I. R
- Sissay B. Mekbib
Welfare Analysis of Energy and Food Inflation: A Representative Agent Approach with the Lesotho Working Class
2011
2011
- P.L. Mohapi
- Retselisitsoe I. Thamae
History of Electricity in Lesotho and the Place of ’Muela Hydropower Plant in the Wider Context of the Southern African Power Pool
2008
2008
T. Tsikoane
Study on the Intercepted Insolation as a Function of Slope and Azimuth of the Surface
Monthly average daily global radiation on surfaces tilted towards the equator and also inclined at various azimuth angels are estimated for three locations in the Southern African region from reported global and diffuse radiation on a horizontal surface. The anisotropic model suggested by Hay is used in obtaining daily radiation at various slopes and orientations. Total annual radiation data are also computed for various tilt and azimuth angles and optimum tilt and azimuth angels corresponding to maximum insolation are obtained for winter, summer and annual collection. The optimum tilt and orientation reported here show some variation from those reported earlier by other investigators and the results are discussed
2007
2007
- K.K. Gopinathan
- N.B. Maliehe
- M.I. Mpholo
The Potential of Renewable Energy Technologies for Rural Development in Lesotho
The potential and utilization of renewable energy technologies (RETs), and energy analysis in Lesotho with emphasis on the contribution of solar energy technologies (SETs) is presented. The heavy reliance of the country on imported fossil fuel coupled with the growing demand for electricity and declining wood fuel supplies call for alternative sources of energy. Taking the average global solar radiation that ranges from 15 to 20 MJ/m 2 and cognizant of the short falls of other renewable energy sources in Lesotho, this paper focuses on the application of solar energy and associated developmental issues. The paper provides a statistical analysis of the energy demand and identifies areas of further growth for SETs. Various application areas of solar energy and their contribution to development in Lesotho together with future prospects for use of solar energy are also discussed. An analysis of the relative merits of using photovoltaic (PV) devices over other renewable energy sources in Lesotho is presented. It is argued that with proper economic support and utilization of efficient RETs, developing countries like Lesotho can meet their basic energy demands and alleviate the problems of energy shortages