109 research outputs found
SMME development through productive use of domestic energy resources
Productive energy services are often overlooked in domestic energy access programs; yet people cannot raise their welfare except by engaging in economic activities. Household energy demand(s) should be viewed in two components, that is, residential and productive energy services. Although the South African government prioritised electricity distribution after independence, this programme was framed in terms of domestic residential use. Thus, the supplied electrical power was limited to low amperage current, adequate only for household lighting and electronics. Intrinsically, the National Electrification Programme and the Free Basic Electricity Programme [1]) that have substantially increased electricity access in the last decade, did little to spur Small, Medium and Micro Enterprises [SMME] growth in urban penumbras and rural localities. Yet, perambulates in these areas indicate that people are engaged in enterprises that yearn for cleaner, reliable, and cost-effective energy inputs. Commercial cooking is a prevalent business in the low-income settlements, which is powered mostly by basic fuels and low efficiency combustion technologies. Although SMMEs contribute about a quarter of gross capital formation, they have a major potential in employment creation, especially within the current context of negative jobs growth in government and large enterprise sectors. This paper argues that SMME growth can be consolidated and accelerated through provision of safe, affordable and efficient energy technologies. Evidence for this claim is based on a quantitative survey that was carried out among street vendors in Alexandra Township, Johannesburg. Discussions were held with the business owners on alternative fuels and modalities for transitioning the informal business sector to use of clean energy resources. The entrepreneurs cite energy poverty and poor premises as the biggest constraints to their businesses
The potential and prospects of improved cookstoves (ICS) in Zimbabwe
In Zimbabwe, alternatives to grid electricity are being sought in the light of limited electricity supply and under-performance of major electricity generation plants following the economic meltdown affecting the country since the mid-1990s, triggered by the Economic Structural Adjustment Programme (ESAP), and more recently due to political instability. Extensive black-outs routinely up to 12 hours per day and even for several days are common in some areas. Consequently, the majority of households continue to rely substantially on wood fuel to meet their basic daily energy needs. Yet the provision of modern energy services and technologies to these households does not seem to be a priority for national energy policy makers. Although improved cookstoves (ICS) are in greater use in rural areas than urban settlements of Zimbabwe, their potential remains largely unexploited. This research aims to highlight the marked potential and current prospects of improved cookstoves in rural and urban communities of Zimbabwe. Ultimately, this research will better inform policy makers, government, academia and the public about cookstove technologies with reduced fuel use, reduced energy costs, and user friendly capacity to improve health in rural and urban communities
Daily activity monitoring in patients with COPD : assessment of upper and lower extremity performance
Influence of coal properties on the performance of fixed-bed coal-burning braziers
Abstract: Informal fixed-bed coal-burning braziers are used extensively in low-income communities of South Africa for space-heating and cooking needs. An investigation was carried out on the effects of coal moisture content and coal quality on the thermal and emissions performance of domestic coal-burning braziers in three field-procured braziers (with three different air ventilation rates), using the bottom- lit updraft (BLUD) and top-lit updraft (TLUD) ignition methods. Results showed that an increase in coal moisture content (from 2.4 wt.% to 8.6 wt.%) led to 18% and 30% decreases in fire-power when using the TLUD and BLUD methods, respectively. The combustion efficiency increased by 25% with an increase in moisture content. Measured carbon monoxide (CO) emission factors increased with an increase in moisture content, while carbon dioxide (CO2) emission factors remained unchanged. The use of A-grade coal resulted in a 49% increase in PM emissions compared with D-grade coal at high ventilation rates, despite no statistically significant differences (p > 0.05) in CO and CO2 emission factors produced between coal grades
Assessment of free basic electricity and use of pre-paid meters in South Africa
In 2000, the African National Congress (ANC) through its election manifesto, made promises to provide free basic services to all poor South Africans. This was later quantified as 6 000 litres of water and 50 kWh of free basic electricity (FBE) monthly per household. Regarding the issuance of FBE, qualifying residents were registered and had to agree to a pre-paid meter being installed. It is argued that the quantity of free basic electricity provided to poor households is inadequate to meet basic needs and improvement of the quality of life. Conversely, there has been resistance to installation and use of pre-paid electricity meters, especially in townships around Johannesburg. Although prepayment systems have been proposed as innovative solutions to the problem of non-payment and affordability in utility services, the use of such mechanisms is still controversial. This paper reviews and assesses free basic electricity and the use of pre-paid electricity meters in South Africa. It also contributes to the on-going debate on FBE and prepayment systems. Recommendations are given on creating viable and stable institutions to curb uncertainties in the provision of electricity services, and methods for identifying changes in aggregate welfare resulting in the adoption of pre-paid electricity meters. Information from this article can be useful for policy-making purposes in other developing countries facing resistance in marketing, dissemination and installation of pre-paid meters
Human and physical energy cycles in a subsistence village in South Africa
A rural, self-contained village in Africa relies mainly on draft animals, energy provided by humans and energy from natural resources, especially firewood, for survival. The human metabolic energy cycle in a rural self-sufficient village in Venda in the Limpopo Province of South Africa is investigated, concentrating on selected activities that make up the routine livelihoods in the wet season. The selected village depended on only a slight extent on external ‘modern’ energy inputs such as electricity, paraffin and diesel in relation to overall energy consumption. Forty-three interviews were conducted in order to identify patterns of labour, sources of food, and foods consumed, while electronic pedometers were employed to quantify energy expended for weeding, firewood and water collection carried out in the wet season in February. A conceptual energy model showing flows of energy from one activity to another within the village was developed. An energy balance model, for an average adult male and female village resident, was developed quantitatively from the conceptual model, taking into account energy intake and energy expenditure. Energy expenditure for males was 1 991 kcal/d; females were 1 965 kcal/d, energy intake for males was 1 953 kcal/d and females was 2 007 kcal/d .This study is significant for future development of rural dwellers. It provides a baseline case for future developments in which modern energy carriers are introduced into remote areas. These may include conventional energy such as electricity, or renewable energies such as low energy devices powered off solar photovoltaic panels or off grid solar/wind systems
Optimising the imbaula stove
In South Africa, human and environmental health implications from domestic solid fuel combustion have spurred interest in cleaner alternative sources of energy and better combustion technologies. Field research among wood and coal burning informal settlements in Johannesburg has shown that the most prevalent mode of combustion is self-made imbaula (brazier) stoves, manufactured from discarded 20 L steel drums. Such stoves are made without any measure of performance optimisation, leading to fuel inefficiency and high emissions - previous field surveys have indicated that the number, size and placement of primary and secondary air inlets (taken as holes below and above the fire grate respectively) vary over a wide range, starting from an extreme with no holes below the grate [1]. Researchers at SeTAR Centre, University of Johannesburg, have set out to develop an enhanced imbaula, by investigating performance in terms of size and distribution of primary and secondary air inlets, and height of grate level. The test imbaulas are constructed out of standard 20 L drums with a height of 360 mm and diameter of 295 mm. A range of hole configurations has been designed, from which selected test configurations are fabricated for experimental evaluation of thermal and emissions properties, using the SeTAR heterogeneous testing protocol. The results indicate that higher hole densities (above and below the grate) lead to higher power outputs and lower specific CO emissions, but with lower thermal efficiency. Further, results indicate that adequate air holes below the grate (primary air) are more important for proper combustion in an imbaula; however this should be synchronised with secondary air in-lets (above the grid) in order to have congruence of all the performance criteria. This study should lead to the development of a set of criteria that can further enhance emissions reductions and fuel efficiency obtained by top-down stove ignition methods (Basa njengo Magogo) for imbaula type stoves
Atmospheric dry and wet deposition of sulphur and nitrogen species and assessment of critical loads of acidic deposition exceedance in South Africa
We tested the hypothesis that acidic atmospheric pollution deposition, originating from the South African central industrial area, poses an environmental threat across a larger region within the dispersal footprint. A network of 37 passive monitoring sites to measure SO2 and NO2 was operated from August 2005 to September 2007. The area extended over the entire northern and eastern interior of South Africa. Monitoring locations were chosen to avoid direct impacts from local sources such as towns, mines and highways. Dry deposition rates of SO2 and NO2 were calculated from the measured concentrations. Concentrations of sulphur and nitrogen species in wet deposition from a previous study were used in conjunction with measured rainfall for the years 2006 and 2007 to estimate the wet deposition over the region. The calculated total (non-organic) acidic deposition formed the basis for an assessment of exceedance of critical loads based on sensitivity of the regional soils. Regional soil sensitivity was determined by combining two major soil attributes available in the World Inventory of Soil Emission Potentials (International Soil Reference and Information Centre). Results indicate that certain parts of the central pollution source area on the South African Highveld have the potential for critical load exceedance, while limited areas downwind show lower levels of exceedance. Areas upwind and remote areas up and downwind, including forested areas of the Drakensberg escarpment, do not show any exceedance of the critical loads
Influence of coal-particle size on emissions using the top-lit updraft ignition method
Abstract: Despite the Government’s intervention of an intensive electrification program in South Africa, which has resulted in more than 87% of households being connected to the grid, a majority of low-income households still depend on coal as a primary source of energy, especially on the central Highveld. In informal settlements, combustion of coal is done in inefficient self-fabricated braziers, colloquially known as imbaulas. Emissions from domestic coal combustion result in elevated household and ambient air pollution levels that often exceed national air quality limits. Continued dependence on coal combustion exposes households to copious amounts of health-damaging pollutants. Despite the health significance of coal-burning emissions from informal braziers, there is still a dearth of emissions data from these devices. Consequently, evaluating the emission characteristics of these devices and to determine the resultant emission factors is needed. The effects of ignition methods and ventilation rates on particulate and gaseous emission from coal-burning braziers are reported in literature. However, to date there are no studies carried out to investigate the influence of the size of coal pieces on brazier emission performance. In this paper, we report on controlled combustion experiments carried out to investigate systematically, influences of coal particle size on gaseous and condensed matter (smoke) emissions from informal residential coal combustion braziers. Results presented are averages of three identical burn-cycles of duration three hours or fuel burn-out, whichever was the soonest
Problematic Activities of Daily Life are Weakly Associated With Clinical Characteristics in COPD
BACKGROUND: Problematic activities of daily life (ADLs) can be the main reason to refer patients with chronic obstructive pulmonary disease (COPD) for pulmonary rehabilitation. To date, information on problematic ADLs and their clinical correlates in COPD remain scarce. This retrospective chart review aimed to identify the most prevalent self-reported problematic ADLs in COPD patients, determine performance and satisfaction scores of these problematic ADLs, and explore the association between 13 clinical determinants and 4 problematic ADL domains. METHODS: A total of 820 COPD patients entering pulmonary rehabilitation assessment were included in this retrospective study. Self-reported problematic ADLs were assessed using the Canadian Occupational Performance Measure, administered by occupational therapists in the form of a semistructured interview. RESULTS: COPD patients (59% male, age 63.6 +/- 9.3 years, FEV1 (%pred): 46.4 +/- 18.4) reported 2999 problematic ADLs. The most prevalent problematic ADLs were walking (68%), stair climbing (35%), and cycling (30%). Moreover, 30% of the patients reported "not able to do any of the scored problematic ADL" and 44% were "not satisfied at all with the performance of any of the scored problematic ADL." Significant but weak associations were found between clinical determinants (eg, physical and psychosocial) and problematic ADLs. CONCLUSIONS: The lack of a strong association between problematic ADLs and clinical determinants emphasizes the need for individualized assessment of these ADLs to allow tailored intervention
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