National Power Utility Research Articles

The effect of coal-fired power plants on ambient air quality in Mpumalanga province, South Africa, 2014–2018

ABSTRACT Several coal-fired power plants (CFPPs) were built in South Africa, mainly in the central Mpumalanga Province, due to an increase in the demand for Eskom, the national power utility, to keep up with socio-economic growth. The CFPPs, of which 90% are owned by Eskom, generate a significant share of the country’s electricity but contribute to the air pollution experienced in the country. The paper discusses sulphur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter of size less than 10 micrometre (μm) in diameter (PM10), using data from 2014 to 2018. The statistics revealed higher PM10 concentrations during winter than in summer and spring at the Kriel and Komati sites; associated with the higher contribution of domestic burning. The study’s results could influence legislation and policies and help to understand the source of poor ambient air quality by assessing the three pollutants within the area of the selected power plants.

Association of coal fired power plants with river water quality in South Africa

The national power utility owns and operates approximately 95% of the coal-fired power plants (CFPPs) in South Africa. It has been hypothesised that power generation activities lead to the acidification and salination of surface water sources in the vicinity of CFPPs, with upwind sites more polluted than downwind sites. For the purpose of this study, three of power utility’s CFPPs were selected, namely Kriel, Komati and Camden Power Plants, which will be reaching the end of their operating lifespan during the mid-to-late 2020 s. The main aim of the study was to analyse the raw water quality data upstream and downstream of these three CFPPs. Raw water supply to the CFPPs for power generation was abstracted from the Rietspruit, Koringspruit and Witpuntspruit streams, respectively. To determine whether the particulate and gaseous emissions affected the water quality from 2012 to 2018, multivariate statistical analyses were applied. The water quality data indicated poor water quality both downwind and upwind of the power plants when thirteen out of 20 (65%) selected water quality variables exceeded the resource quality objectives (RQO) limits, which could be attributed to anthropogenic activities such as agriculture, coal burning and coal mining; causing increased acidity and salinity in the various water sources. In conclusion, the study suggested that there is no direct correlation between the emissions from coal burning and the coal-fired power plants receiving streams; an indication that power generation may not be the only anthropogenic factor influencing the water quality of the streams.

High-capacity coal trucks to reduce costs and emissions at South Africa's power utility

South Africa's national power utility, Eskom, is under growing pressure to increase its power generation capacity in the face of national rolling blackouts while also containing costs, increasing revenue, and reducing its environmental impact. While the entity embarks on an ambitious $ 10 billion 2050 decarbonisation plan, there are short-term opportunities to save costs and emissions in parts of its business through relatively simple interventions. In this work, we investigate the transport of coal to Eskom's power stations. We focus on the approximately 30 million tonnes transported by road, where ‘high-capacity vehicles’ (HCVs) have already demonstrated significant productivity improvements in a national pilot project in South Africa. First, the current costs and emissions associated with the current transport activity are calculated, which amount to approximately ZAR 4 billion (US$250 m) and 230,000 t of CO2 respectively per year. A case is then presented for transitioning the coal transport fleet to 74-t high-capacity vehicles, which is calculated to save Eskom up to ZAR 248 million (US$15 m) and 35,000 t of CO2 each year. In addition, we show that the more road-friendly HCV fleet would result in a reduction in road damage valued at ZAR 50 million (US$3 m) per year. Ultimately, these cost figures represent savings to the South African taxpayer, as both Eskom and the road authorities are state entities. The precise cost benefit to Eskom, however, will depend on the nature of its coal supply contracts with local mines and transporters, but it is likely that market forces will enable these savings to be realised throughout the supply chain.

ISO 13909 compliant contractual payment station coal sampling plant: process design and equipment selection for chemical, physical and moisture sampling

The paper discusses the process design and mass balance highlights to illustrate the ISO 13909 compliance of a 4-year-running contractual payment station sampling plant. The plant is used to sample -60mm coal supply to a coal fired power station infrastructure belonging to the South African National Power Utility. Payment parameters are proximate analysis (Calorific Value, Ash-, Sulphur content), physical (size and abrasion index) and moisture content. Over and above ergonomic physical samples and timeous moisture samples, the plant also delivers the crushed chemical sample in triplicate for buyer-, seller- and referee analysis. The lot period was defined as 24 hours production while the system compliance was designed around mass-based sampling. Production varies over a wide range of throughout tonnages from 800-3600 ton/h as dictated by complex boiler and silo operational requirements. The plant required a unique operational philosophy to adapt the number of primary increments (and corresponding time interval) per sublot size to the varying production rates which over a fix lot period results in varying lot size. Furthermore, a contractual grade, calibrated, 6-idler belt scale is used to measure the instantaneous conveyor load which in turn controls the cutter speed via a programmable logic controller (PLC) prompted variable speed drive (VSD) setpoint to sample fixed increment mass to represent fixed production mass interval. The primary belt end crosscut sampler boasts a unique articulated joint design sample chute to fit down the high sample tract; eliminating the delineation errors associated with the previous competitor design.

Cutting without Cutting Connection: The Semiotics of Power Patrols in Urban Tanzania

Before the total cutoff of a household for unpaid electrical bills, and in anticipation of the violence it might precipitate, national power utility inspectors in Dar es Salaam have recourse to a gradient of ‘soft’ disconnections designed to signal good faith and encourage repayment. Drawing on a mixture of semiotics and exchange theory, this article argues that such soft disconnections may be understood as moments when the shared grounds of the household-utility relation—both the physical power network and social commitments it embodies—become figured, modified, and ultimately preserved in the face of urban postcolonial strain. Whereas semiosis is often thought of as a kind of infrastructural bridge that links sign to interpretant (or object to sign), the inspectors’ reflexively phatic signaling of common grounds highlights the thoroughly semiotic nature of infrastructure itself. More generally, the very presumption and preservation of shared grounds is a salutary alternative to the anti-relational violence and extinction that characterizes much of the contemporary world.

Status of Micro/Mini-Grid Systems in a Himalayan Nation: A Comprehensive Review

Nepal is a Himalayan country with its 83% of its geography being composed of hills and mountains. Around 22% of the Nepalese population is not receiving electricity through the national power utility and is forced to identify alternative approaches to electrification. The Micro/Mini-Grid (MG) system is one of the promising approaches in terms of cost, reliability and performance for rural electrification, where electrification through national power utility is not techno-economically feasible. However, various issues must be identified and considered during the implementation of MGs in a rural community. In this paper, numerous technical, social and management issues are identified and discussed relating to the implementation and operation of reliable and stable MGs in the Himalayas. To our knowledge, this is the first scientific work that presents a comprehensive review of Himalayan MGs and their associated elements. This article reviews the available research articles, project documents, and Government reports on MG development, from which a clear roadmap is constructed. From the comprehensive study, it is observed that the existing MGs are not adequately designed for the specific area, considering the local resources and local information. Based on the identified issues, some practical and efficient recommendations have been made, so that future MG projects will address the possible problems during the design and implementation phase.

Socio-Economic Effects of Load Shedding on Poor Urban Households and Small Business Enterprises in Lusaka, Zambia

Zambia has in the recent past witnessed an increase in economic activities which has led to an increased energy demand. This increased demand for energy has overshot the hydroelectric power generating capacity. Consequently, the national power utility company, the Zambia Electricity Supply Corporation (ZESCO) instituted nationwide load shedding schedules that last up to 12 hours daily. This development has potentially far reaching social and economic effects on the lives and operations of poor urban residents and small scale business enterprises (SMEs) that routinely depend on stable access to electricity. With a focus on two low income residential areas, namely Ng’ombe and Kalingalinga residential areas, this study explored how residents and SMEs of the capital city, Lusaka have been affected by the recent spate of load shedding in the city. A total of 200 households and 14 SMEs from Ng’ombe and Kalingalinga were interviewed. Results show that load shedding, which occurs daily in the two study sites has caused massive disruptions to the daily lives and operations of the households and small businesses respectively. Over time, the load shedding phenomena has gotten worse and become a major political issue, reflecting the hardships for households and businesses in Zambia. On this basis, this study recommends that the government provides subsidies on alternative energy appliances such as portable diesel solar generators for small business enterprises and more favourable electric tariff rates for business that shift their manufacturing activities to night time so as to reduce demand for electricity during peak periods.

Alternatives for small, medium and micro scale enterprises participation in the renewable energy industry – small scale embedded generation review

Over the past decade South Africa has seen an increase in the uptake of solar energy as a result of the Renewable Energy Independent Power Producer Programme, which led to a sharp increase in procurement of utility-scale solar PV projects. On the other hand, the load shedding which was implemented by the national power utility in response to electricity supply and demand challenges resulted in the rise in procurement of small-scale embedded generation solar PV systems. While the REIPPPP has had minimal impact in terms of incorporating small, medium and micro scale enterprises (SMMEs) in the renewable energy value chain, there is a significant opportunity for SMMEs in the small scale embedded generation (SSEG) market segment. This study investigated the challenges and opportunities for SMMEs in SSEG.

Waterberg coal characteristics and SO2 minimum emissions standards in South African power plants

Key characteristics of coal samples from the supply stock to the newly commissioned South African National Power Utility's (Eskom's) Medupi Power Station – which receives its supply coal from the Waterberg coalfield in Lephalale (Limpopo Province, South Africa) – were evaluated. Conventional coal characterisation such as proximate and ultimate analysis as well as determination of sulphur forms in coal samples were carried out following the ASTM and ISO standards. Coal was classified as medium sulphur coal when the sulphur content was detected in the range 1.15–1.49 wt.% with pyritic sulphur (≥0.51 wt.%) and organic sulphur (≥0.49 wt.%) accounted for the bulk of the total sulphur in coal. Maceral analyses of coal showed that vitrinite was the dominant maceral (up to 51.8 vol.%), whereas inertinite, liptinite, reactive semifusinite and visible minerals occurred in proportions of 22.6 vol.%, 2.9 vol.%, 5.3 vol.% and 17.5 vol.%, respectively. Theoretical calculations were developed and used to predict the resultant SO2 emissions from the combustion of the Waterberg coal in a typical power plant. The sulphur content requirements to comply with the minimum emissions standards of 3500 mg/Nm3 and 500 mg/Nm3 were found to be ≤1.37 wt.% and ≤0.20 wt.%, respectively.

Drivers of Bird Species Richness within Moist High-Altitude Grasslands in Eastern South Africa.

Moist high-altitude grasslands in South Africa are renowned for high avifaunal diversity and are priority areas for conservation. Conservation management of these areas conflicts with management for other uses, such as intensive livestock agriculture, which requires annual burning and leads to heavy grazing. Recently the area has become target for water storage schemes and renewable electricity energy projects. There is therefore an urgent need to investigate environmental factors and habitat factors that affect bird species richness in order to optimise management of those areas set aside for conservation. A particularly good opportunity to study these issues arose at Ingula in the eastern South African high-altitude grasslands. An area that had been subject to intense grazing was bought by the national power utility that constructed a pumped storage scheme on part of the land and set aside the rest for bird conservation. Since the new management took over in 2005 the area has been mostly annually burned with relatively little grazing. The new management seeks scientific advice on how to maintain avian species richness of the study area. We collected bird occurrence and vegetation data along random transects between 2006 and 2010 to monitor the impact of the new management, and to study the effect of the habitat changes on bird species richness. To achieve these, we convert bird transect data to presence only data to investigate how bird species richness were related to key transect vegetation attributes under this new grassland management. First we used generalised linear mixed models, to examine changes in vegetation grass height and cover and between burned and unburned habitats. Secondly, we examined how total bird species richness varied across seasons and years. And finally we investigated which habitat vegetation attributes were correlated with species richness of a group of grassland depended bird species only. Transects that were burned showed a larger decrease in vegetation cover compared to transects that were not burned. Grass height increased over time. Bird species richness was highest in summer compared to other seasons and increased over time. Overall bird species richness increased over the three summer surveys but species richness of birds that prefer heavily grazed habitat showed little change over the three years. Changes in bird species richness were best explained by the model with grass height for combined species richness of grassland depended birds but also for birds that prefer heavy grazing when treated alone. On one hand birds that prefer moderate grazing were best explained by a null model. However, overall bird species richness was better positively correlated to grass height than grass cover or dead grass. We conclude that frequent burning alone with relatively reduced grazing led to higher but less dense grass, which benefited some species and disadvantaged others. We suggest that management of this grassland use combination of fire and grazing and leave some areas unburned to accommodates birds of various habitat needs.

Repositioning Electricity Planning at the Core: An Evaluation of South Africa's Integrated Resource Plan

Energy, and electricity issues in particular, have been high on the South African agenda since the 2008 crisis, which saw the country’s national power utility Eskom implement rolling load shedding and cut supplies to a number of large customers, such as mines and minerals beneficiation plants. As South Africa experienced in 2014 the most stringent power cuts since 2008, reviewing the current electricity planning process is both a timely and necessary exercise. This review, based on an internationally-recognised framework, unpacks the key pillars of the Integrated Resource Plan (IRP) and reviews South Africa’s performance, with the objective of shedding light on the role and the implications of planning on the country’s electricity supply and pricing. It is the first attempt at applying this international framework to the South African context.The 10 elements covered are: 1) planning process; 2) plan objectives; 3) review of previous plans; 4) demand forecast methodology; 5) resource options assessment; 6) policy instruments to achieve objectives; 7) regulatory and institutional frameworks; 8) investment financing; 9) social and environmental considerations; and 10) promotion of innovation and anticipation of emerging challenges.

Solar thermal systems for large high rise buildings in Malaysia

Malaysia and Southeast Asia in general, is a very suitable region for implementing solar technologies because Malaysia is located near the equatorial line, where sunlight remains strong and stable throughout the year. The average solar radiation per month is 400–600MJ/m, so Malaysia should fully utilise solar energy because it is clean and sustainable. Solar energy can be considered as renewable energy that is environmentally friendly and can be continually replenished from time to time. The use of renewable energy is expected to increase exponentially in the future because natural resources could become depleted due to the increasing usage due to growing population in a world hungry for energy consumption for domestic, industrial and leisure purposes. Solar energy can provide infinite amount of energy because the sun can last for another few billions of years from now. So, many advanced nations have developed solar technologies to be implemented in a variety of sectors that include power generation and domestic water heating. The geographical location of Malaysia and other Southeast Asian countries has enabled this region to be different from Western European countries that could only utilise solar energy through technology. Malaysia is located near the equatorial line, and so the sunlight in Malaysia remains strong and stable throughout the year. The average solar radiation per month for Malaysia is 400–600MJ/m, and hence the country has a very high prospect to develop large-scale solar power plants. For now, Malaysian government is putting a lot of effort to promote solar energy use in Malaysia. The initial implementation of solar energy in Malaysia is for domestic solar water heaters. Unfortunately, the use of solar water heaters domestically and commercially is still low. According to estimate, around 45,000 buildings in Malaysia are appropriate for solar thermal usage, but 10% of them are not suitable because of roof shadings and structure. Different economic sectors in Malaysia can provide 110,000,000m of building surfaces for solar thermal applications and so about 75GW of power can be produced from this application. The photovoltaic (PV) technology was first built in Malaysia during 1980s in order to provide electricity to rural areas. Tenaga Nasional Bierhad, the national utility company, began to set up grid-connected PV systems as an alternative for national power utility and power production in 1998. One PV system was built at a British Petroleum petrol station along KESAS highway with 8 kWp capacity and another one built at the Solar Energy Research Institute at National University of Malaysia with 5.5 kWp capacity. In 2000, the first Malaysian Building Integrated Photovoltaic (BIPV) system was built in Port Dickson with 3.15 kWp capacity. Malaysia’s universities are focusing on five majors of R&D for solar technologies, including inverters, PV concentrators, cells fabrications, hybrid systems and energy conversion tracking systems. The funding for the research in PV technologies is provided by Ministry of Science, Technology and Innovation (MOSTI). Malaysian government also provides tax incentives so that a portion of the total cost of installing PV system can be deducted. The Feed-InTariffs can be the most promising policy because the utility pays a prestige price for the grid-connected PV electricity generated by system proprietors, and there is a 20-year of guarantee for the price. In short, Malaysia has a huge prospect to implement large-scale solar thermal systems. A solar collector is a type of heat exchanger that converts solar radiant energy into heat energy. Flat plate collector (FPC) is a type of solar thermal collectors. It will require minimal maintenance and is mechanically simple and with low installation cost. Major applications of solar energy like solar water heating, industrial process heating and air conditioning are using FPCs. Thermal performance for FPCs is treated in concise details, and the equations for collector performance can be reduced to simpler forms for performance analysis. Evacuated tube collectors (ETCs) contain heat pipe inside a vacuum-sealed tube. The

Potential and future of concentrating solar power in Namibia

The Namibian electricity sector has mainly relied on electricity imports from the Southern African Power Pool (SAPP) over the last decade. However, a growth in electricity demand and scarce import options could cause energy shortages. Therefore, new power plants ought to be commissioned in the near future to avoid the forecasted energy crisis. In this context, Concentrating Solar Power (CSP) generation is regarded as an appropriate alternative to conventional energy technologies, particularly for the excellent solar regime available in Namibia. The study presents a GIS analysis that identifies suitable areas for CSP establishment. A broad range of geographical parameters such as solar radiation, topography, hydrology or land use are examined. The calculations show that the CSP ceiling generation in Namibia is equivalent to 70% of the worldwide electricity production. Moreover, the study offers a scenario analysis where concrete CSP alternatives are compared to coal-fired plant projects developed by the national power utility. Meteonorm and System Advisor Model (SAM) are used to design CSP alternatives located in the area offering the best combination between high solar irradiation and short distances to the infrastructures. Despite the affordability concern which has to be addressed with sound financial instruments, CSP represents a seminal opportunity for the energy sector in

Power sector reforms in Ethiopia: options for promoting local investments in rural electrification

An estimated 13% of Ethiopia's population has access to electricity. Almost all electrified centres are urban, with rural areas as well as most small rural towns largely unelectrified. Rural electrification (RE) thus remains a major challenge to the power sector of Ethiopia. The national power utility (EEPCO) has traditionally been assigned the task of electrifying rural demand centres. EEPCO has, however, concentrated on the more developed and profitable urban areas. The objective of this article is to present the findings of a study that examined whether the ongoing power sector reforms in Ethiopia can attract private investment in RE as an alternative to the sole reliance on EEPCO. Initial findings of the study indicate that private investment in RE can be enhanced with some improvement in the legal and regulatory provisions, along with extension of technical assistance from EEPCO to private investors.