23 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
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
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
Aerosol particle morphology of residential coal combustion smoke
A study carried out at the University of Pretoria characterised aerosol particle morphology of residential coal combustion smoke. The
general approach in this study was on individual particle conglomerations because the radiative, environmental, and health effects
of particles may depend on specific properties of individual particles rather than on the averaged bulk composition properties. A
novel, miniature denuder system, developed and tested at the University of Pretoria, was used to capture particle emissions from
the coal fires. The denuder consists of two silicone rubber traps (for gas phase semi-volatile organic compound monitoring) in series
separated by a quartz fibre filter (for particle collection). The denuders were positioned 1 m away from the fire and were connected
to pumps that sampled ~5 litres of air over a 10 min sampling interval. A JSM 5800LV Scanning Electron Microscope with a Thermo
Scientific EDS was used to analyse the structure and morphology of different aerosol samples from the quartz fibre filters. Eight
samples from the different fire lighting methods were selected for SEM analysis. The punched samples were sputter coated with gold
for ~15 minutes using a K550 Emitech Sputter Coater. Results show that apart from the fine and ultra-fine particles, coal smoke from
domestic burning also contains aerosols greater than 5 μm in diameter. Consequently, we describe the potential for generation of
‘giant’ carbonaceous soot conglomerates with outer diameters of 5 to 100 μm. However, the exact mechanism for formation of such
large soot conglomerates remains to be determined. We also describe the presence of spherules and solid ‘melted toffee’ irregular
surfaces. Circumstantial evidence is used to postulate and discuss the possible modes of formation in terms of condensation, and
partial melting. This work provides a description of the modes of formation and transformation of conglomerates originating from low
temperature (<8000C) coal combustion.The University of Johannesburg for financial support
through a URC/Faculty of Science grant to the SeTAR Centre
and a grant from the Global Alliance for Clean
Cookstoves (GACC) to the SeTAR Centre as a Regional Stove
Testing and Development Centre.http://www.cleanairjournal.org.zaam201
Influence of fire-ignition methods and stove ventilation rates on gaseous and particle emissions from residential coal braziers
Despite extensive electrification of low-income residential areas on the South African Highveld, extensive use is still made of wood and coal as domestic fuels, particularly for winter space heating. In informal settlements characterised by poverty and lacking electrification, coal is combusted in non-standardised, inefficient and polluting metal braziers, colloquially known as imbaulas. Copious emissions from domestic coal fires result in elevated household and ambient air pollution levels well above national air quality limits. Despite the severity of this pollution as a public health issue, emissions data from residential coal-burning braziers are still scarce. Consequently, there is a need to evaluate the emission characteristics of these devices. In this paper, we report on controlled combustion experiments carried out to investigate systematically influences of fire-ignition methods and stove ventilation rates on gaseous and condensed matter (smoke) emissions from informal residential coal combustion braziers. Two methods of stove ignition—conventional bottom-lit updraft (BLUD) and the top-lit updraft (TLUD) (colloquially known as the Basa njengo Magogo) were investigated. Emission factors (EFs) were found to be dependent on fire ignition method and stove ventilation rates. The top-lit ignition method reduces PM10/PM2.5 by 76% to 80% compared to the BLUD method. Carbon monoxide emissions do not change significantly with the ignition method. Pollutant emissions from normal combustion in high ventilation conditions were low compared to pollutants emitted when an oxygen deficient atmosphere was created under low ventilation conditions. High stove ventilation rates resulted in a 50% reduction in PM10/PM2.5 emissions compared to the low ventilation rates. Emissions of gaseous and particulate matter from incomplete combustion can be minimised by design optimisation of the braziers. Ideally, the emissions of condensed matter particles (which form the bulk of emitted particles in residential coal fires) can be reduced through good mixing of emitted gases and air, and by ensuring a long residence time in the high temperature oxygen rich post combustion zone, to allow for complete oxidation. This study is significant in that it presents the first systematic and comprehensive study of factors affecting emissions from coal braziers