6 research outputs found
AN ANALYSIS OF THE SOCIOECONOMIC IMPACTS OF ICT’S UTILIZATION BY SMALHOLDER FARMERS ON FARMING COMMUNITIES IN ZIMBABWE
The inefficient administration and coordination of input and market linkages in sub Sahara Africa has traditionally been the major deterrent to the achievement of agricultural production and business efficiencies due to communication bottlenecks. The dispensation of modern Information Communication Technologies (ICT’s) have undoubtedly improved communities livelihood with regard to these linkages through efficient dialogue communication channels. This research paper intends to make a socio -economic impact analysis of ICT’s contribution to rural (small holders) and marginalised urban (urban slum resettlement zones) agricultural communities in Zimbabwe’s. The objectives of the study are defined candidly with focus on efficiencies relating to input and market linkages and the socio-economic result thereof. The methodology is briefly outlined, the study variables are crystallised into 6 focal areas and a justification is provided which details why this study is valuable and its contribution to the further improvement of the livelihood of farming communities in Zimbabwe
A techno-economic model for optimising component sizing and energy dispatch strategy for PV-diesel-battery hybrid power systems
This paper presents the development and application of a simple spreadsheet-based simulation model for sizing, energy performance evaluation and economic analysis of PV-diesel-battery power supply systems. The model is employed to generate a set of sizing curves that define the design space for hybrid systems using dimensionless generator component size variables, for a specified supply reliability and diesel energy dispatch strategy. The component size combination with the least unit cost of energy is selected among the many possible combinations satisfying a desired loss-of-load probability. Storage battery and diesel generator lifespan, as well as generator fuel efficiency, which depend on the operational loading stress of these components, are recognised as important variables in the economics of the system. The lifespan of the battery is premised to depend on the depth and rate of discharge of the operating cycles, while both the diesel generator lifespan and fuel efficiency are dependent on the degree and frequency of partial loading. The choice of diesel generator dispatch strategy was shown to be another important factor influencing the energy performance and economics of the system. The outputs of the model reveal several important sizing, operational and economic characteristics of the systems, and enables appraisal of comparative advantage of different types of designs and operational strategies. The merits of the hybrid concept are well demonstrated by the study results
Mapping wind power density for Zimbabwe: a suitable Weibull-parameter calculation method
The two-parameter Weibull probability distribution function is versatile for modelling wind speed frequency distribution and for estimating the energy delivery potential of wind energy systems if its shape and scale parameters, k and c, are correctly determined from wind records. In this study, different methods for determining Weibull k and c from wind speed measurements are reviewed and applied at four sample meteorological stations in Zimbabwe. The appropriateness of each method in modelling the wind data is appraised by its accuracy in predicting the power density using relative deviation and normalised root mean square error. From the methods considered, the graphical method proved to imitate the wind data most closely followed by the standard deviation method. The Rayleigh distribution (k=2 is also generated and compared with the wind speed data. The Weibull parameters were calculated by the graphical method for fourteen stations at which hourly wind speed data was available. These values were then used, with the assistance of appropriate boundary layer models, in the mapping of a wind power density map at 50m hub height for Zimbabwe
Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.
BACKGROUND: Child stunting reduces survival and impairs neurodevelopment. We tested the independent and combined effects of improved water, sanitation, and hygiene (WASH), and improved infant and young child feeding (IYCF) on stunting and anaemia in in Zimbabwe. METHODS: We did a cluster-randomised, community-based, 2 × 2 factorial trial in two rural districts in Zimbabwe. Clusters were defined as the catchment area of between one and four village health workers employed by the Zimbabwe Ministry of Health and Child Care. Women were eligible for inclusion if they permanently lived in clusters and were confirmed pregnant. Clusters were randomly assigned (1:1:1:1) to standard of care (52 clusters), IYCF (20 g of a small-quantity lipid-based nutrient supplement per day from age 6 to 18 months plus complementary feeding counselling; 53 clusters), WASH (construction of a ventilated improved pit latrine, provision of two handwashing stations, liquid soap, chlorine, and play space plus hygiene counselling; 53 clusters), or IYCF plus WASH (53 clusters). A constrained randomisation technique was used to achieve balance across the groups for 14 variables related to geography, demography, water access, and community-level sanitation coverage. Masking of participants and fieldworkers was not possible. The primary outcomes were infant length-for-age Z score and haemoglobin concentrations at 18 months of age among children born to mothers who were HIV negative during pregnancy. These outcomes were analysed in the intention-to-treat population. We estimated the effects of the interventions by comparing the two IYCF groups with the two non-IYCF groups and the two WASH groups with the two non-WASH groups, except for outcomes that had an important statistical interaction between the interventions. This trial is registered with ClinicalTrials.gov, number NCT01824940. FINDINGS: Between Nov 22, 2012, and March 27, 2015, 5280 pregnant women were enrolled from 211 clusters. 3686 children born to HIV-negative mothers were assessed at age 18 months (884 in the standard of care group from 52 clusters, 893 in the IYCF group from 53 clusters, 918 in the WASH group from 53 clusters, and 991 in the IYCF plus WASH group from 51 clusters). In the IYCF intervention groups, the mean length-for-age Z score was 0·16 (95% CI 0·08-0·23) higher and the mean haemoglobin concentration was 2·03 g/L (1·28-2·79) higher than those in the non-IYCF intervention groups. The IYCF intervention reduced the number of stunted children from 620 (35%) of 1792 to 514 (27%) of 1879, and the number of children with anaemia from 245 (13·9%) of 1759 to 193 (10·5%) of 1845. The WASH intervention had no effect on either primary outcome. Neither intervention reduced the prevalence of diarrhoea at 12 or 18 months. No trial-related serious adverse events, and only three trial-related adverse events, were reported. INTERPRETATION: Household-level elementary WASH interventions implemented in rural areas in low-income countries are unlikely to reduce stunting or anaemia and might not reduce diarrhoea. Implementation of these WASH interventions in combination with IYCF interventions is unlikely to reduce stunting or anaemia more than implementation of IYCF alone. FUNDING: Bill & Melinda Gates Foundation, UK Department for International Development, Wellcome Trust, Swiss Development Cooperation, UNICEF, and US National Institutes of Health.The SHINE trial is funded by the Bill & Melinda Gates Foundation (OPP1021542 and OPP113707); UK Department for International Development; Wellcome Trust, UK (093768/Z/10/Z, 108065/Z/15/Z and 203905/Z/16/Z); Swiss Agency for Development and Cooperation; US National Institutes of Health (2R01HD060338-06); and UNICEF (PCA-2017-0002)
Dimensioning of hybrid solar-battery-grid micro-energy power systems to alleviate domestic power outages in urban Zimbabwe: A reliability-cost approach
International Renewable Energy Symposium (IRES 2015) Conference Proceeding,Power outages are rampant in most of Southern African countries due to inadequate electricity generation capacity by the utilities in these countries. This situation results in direct and indirect costs to both the consumers of electricity- those that are lucky to be connected to the electricity grid- and to the utilities themselves. In a region endowed with abundant solar resource, hybrid solar-battery-grid micro-power systems are an attractive option to alleviate the power outage problems, resulting in improved electricity supply reliability at reasonable cost of energy. In this study, an approach to the dimensioning of these hybrid power systems, for domestic consumers in Zimbabwe is presented. For a given hourly load profile, and for a desired level of electricity supply reliability, a combination of solar photovoltaic (PV) array and storage battery can be specified in a fairly general way (i.e. independent of size of daily load) by use of dimensionless component size parameters, A/Ao and Bcap/Lday, respectively, and defined in the study. A “home-made†Excel program is utilized for performing the necessary simulation of the systems. A plot of the dimensionless battery size parameter, Bcap/Lday, versus the PV array size parameter, A/Ao, maps the locus of points of system-component combinations resulting in a desired level of electricity supply reliability. Least levelized cost of energy (LCOE) is then used as the objective function to select among systems delivering the same level of reliability. Properly dimensioned hybrid solar-battery-grid micro-energy systems are found to be much cheaper than the commonly used approach to alleviating power outages by use of an auxiliary petroleum fuel generator.,Namibia Energy Institute (NEI