89 research outputs found

    Impact of climate change and irrigation development on hydropower supply in the Zambezi River Basin, and implications for power sector development in the Southern African Power Pool

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    This thesis investigates the hypothesis that the combination of future changes in climate and development (primarily irrigation) in the Zambezi River Basin (ZRB) threatens the technical and economic viability of existing and planned hydropower plants, and in turn the expansion plans and costs of the regional power system for Southern African countries. This hypothesis is evaluated using the following three questions to structure the analysis. ● How could future climate and irrigation expansion in the Zambezi River Basin affect hydropower generation potential? ● How could development in Southern Africa affect power demand, and how might this demand be met? ● How could the changes in water availability for hydropower (i.e. due to climate change and development) affect regional electricity expansion plans, generation costs and greenhouse gas emissions? The methodological tool used to address the first research question is the Water Evaluation and Planning (WEAP) scenario modelling system, developed by Stockholm Environment Institute. WEAP is a combined hydrological and water allocation model that is widely used internationally. The modelling demonstrates that the change in future climate is the overwhelming driver of future production at almost all hydropower plants in the ZRB over the study period of 2010-2070. The difference in mean generation under wetting and drying climates (i.e. difference between the values under wet and dry scenarios) is 12-16% for individual existing plants. This difference is as much as 30% for individual new plants, with all plants other than Batoka showing variation in mean annual generation of more than 13%. The impact of irrigation, on the other hand, is mainly an issue for plants downstream from Kariba, and even then the magnitude is typically less than a third of the impact of the alternative climates. The water modelling results therefore do not vary significantly across alternative development futures, because the accelerated irrigation development is still not large enough to dramatically impact hydropower. The second research question is analysed using Stockholm Environment Institute's Long- Range Energy Alternatives Planning (LEAP) model to trace the impacts of socio-economic development on electricity supply and demand. The analysis combines a simulation of current utility plans with a least cost optimisation to meet the remainder of supply needed over the long term. The analysis shows that the underlying socio-economic drivers of demand lead to both a dramatic increase in total electricity demand and a shift across sectors and countries within the region. Total electricity demand for the Southern African Power Pool (SAPP) region increases by 8-14 times over period from 2010 to 2070, with the combined demand from the rapidly growing countries of Democratic Republic of Congo (DRC), Mozambique and Zambia becoming larger than South African demand by 2070. At the sectoral level, the share of total demand from the extractive and manufacturing sectors increases from 59% in 2010 to 70% in 2070 under the most optimistic development scenario, based on a compound annual growth rate of consumption in excess of 5%. Activity level growth is the main driver of demand growth. Comparison with other studies in the region show that the mid-term demand estimates (e.g. 2025-2030) in this study are generally within the range of other research, with somewhat higher demand estimates from the most optimistic development scenario. Total electricity supply required over the longer term is met through the addition of 400-1400 GW of new capacity, or 8-20 times the current capacity of the region. More strikingly, the power mix shifts from almost 80% coal-fired power to 24-44% coal by 2070, with the balance being supplied mainly by solar, wind, hydropower and nuclear generation. The regional shift is no less dramatic, with South Africa's share of total generation declining from 84% to only a third, based on the higher growth rates in countries such as DRC, Mozambique and Zambia. The third research question is the most important in terms of the original contribution of this PhD thesis. Applying the WEAP and LEAP tools to an integrated multi-country system is a methodological advance pioneered in this thesis, showing that the integrated methodology can provide information to address not only the immediate questions about generation choices under an uncertain future climate, but also system costs and GHG emissions. The analysis shows that the reduction in hydropower generation under a drying climate leads to a shift in both capacity expansion choices and the operation of the regional power system, while the increases in hydropower output under a wetting climate are smaller. In other words, the "downside" of future climate changes is larger than the potential "upside". At an aggregate level, the increases in generation costs are a small share of total generation costs (i.e. less than 1% over the full study period compared to the baseline climate). However, the impact on generation costs for hydro-dependent countries such as Mozambique, Zambia and Zimbabwe is considerably larger, and these countries also gain more under a wetting climate. Finally, because some hydropower could be displaced by coal, regional GHG emissions could increase by more than 6 MtCO2 per year in the medium term, or the equivalent of a large coalfired power station. This research has important policy implications for the water and electricity sector in the region. The potential transformation of the electricity supply sector would require a fundamental shift in resource use, grid management and infrastructure development in the region. The shift in the resource base for electricity generation will pose challenges for grid integration and balancing supply and demand across countries and load centres. Historically, the development of transmission capacity, and the resulting trade in electricity, has been constrained by the political and economic realities of the region. There are signs that the politics could be shifting, however, for political, economic and environmental reasons. In addition, the relatively low consumption of water in the Zambezi River Basin in the past meant that explicit trade-offs across sectors and across countries posed less of a challenge for the basin overall. This is very likely to change in the future, as increased demand from all sectors, and major potential changes in climate will require more explicit agreements across both countries and user groups on how best to utilise a limited resource. This research demonstrates the tools that could be used to integrate both climate change and upstream development demands into the feasibility studies before investment decisions are made. The research also illustrates the first steps toward integrating climate change and upstream development considerations into national and regional electricity planning. The electricity and water sectors are important contributors to the development of the Southern Africa, and hydropower in the ZRB lies at the intersection of these fields. Climate change, however, has the potential to add increased stress on these sectors, both directly and indirectly, and yet is not being considered in many individual hydropower power investments, or in national or regional electricity planning. The integrated scenario analysis approach in this thesis demonstrates how the impacts of climate change, as well as increased irrigation demand for water, could be assessed not only for specific hydropower plants and for the entire sector power sector. Preparing for this possible range of future climates can increase the resilience of the sector and reduce the risk of stranded assets in the power sector

    Financial protocol for South Africa's climate change mitigation assessment

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    Suppressed demand in the clean development mechanism: conceptual and practical issues

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    One of the challenges of applying greenhouse gas emission accounting approaches in poor communities is that the current consumption of many household services (e.g. heating and cooking, lighting and potable water) may not reflect the real demand for those services. This could be the result of lack of infrastructure, lack of natural resources or poverty, particularly the high costs of these services relative to household incomes. The situation of ‘suppressed demand’ creates a problem for setting emissions baselines against which to compare project performance, and has negatively affected CDM project development in Africa, Least Developed Countries and other regions with very few CDM projects. Ironically, although new large-scale power plants do not have to show that they actually displace other plants (existing or new), many small-scale energy projects can only claim credit for displacing historical (very low level) emissions from households. While the CDM rules are evolving to consider suppressed demand, much more can be done to catalyse investment in these types of climate change mitigation projects in poor communities. Furthermore, making progress will require significant expert and stakeholder input to ensure that simplification is balanced with maintaining overall environmental integrity

    Suppressed demand in the clean development mechanism: conceptual and practical issues

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    One of the challenges of applying greenhouse gas emission accounting approaches in poor communities is that the current consumption of many household services (e.g. heating and cooking, lighting and potable water) may not reflect the real demand for those services. This could be the result of lack of infrastructure, lack of natural resources or poverty, particularly the high costs of these services relative to household incomes. The situation of ‘suppressed demand’ creates a problem for setting emissions baselines against which to compare project performance, and has negatively affected CDM project development in Africa, Least Developed Countries and other regions with very few CDM projects. Ironically, although new large-scale power plants do not have to show that they actually displace other plants (existing or new), many small-scale energy projects can only claim credit for displacing historical (very low level) emissions from households. While the CDM rules are evolving to consider suppressed demand, much more can be done to catalyse investment in these types of climate change mitigation projects in poor communities. Furthermore, making progress will require significant expert and stakeholder input to ensure that simplification is balanced with maintaining overall environmental integrity

    External cost of electricity generation: contribution to the Integrated Resource Plan 2 for Electricity

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    The international studies on energy externalities and the local studies in South Africa suggest that the high impact areas for power generation are impacts of climate change and health impacts of outdoor air pollution. Climate change impacts are by far the greatest. The health costs due to outdoor air pollution are considered quite low based on national studies, though these may be underestimated. Damage cost from acid mine drainage is also thought to be significant, and could be substantially higher than reported here. External costs of electricity generation are a necessary factor in modelling the IRP 2. To be consistent, external costs must be added to the modeller’s reference case and to all policy cases or scenarios. In the multiple criteria decision-making process, the external costs should be reported as a distinct criterion. The weighting of this criterion relative to others (cost, carbon, and access) should be discussed with stakeholders. Although the external cost presented here are appropriate for input into the IRP 2, an extensive national review must be completed for future IRPs. Furthermore, the Integrated Energy Plan (IEP) should take additional factors into account: health impacts of indoor air pollution (important in poor households, as well as industry); noise from transport, and other poverty-related issues such as wealth impacts of paraffin fires and burns, and social costs of fuel wood scarcity

    Climate change briefings

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    Developing patient education to enhance recovery after colorectal surgery through action research: a qualitative study

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    Objectives: To understand the role of preoperative education for patients undergoing colorectal surgery by involving patients, carers and staff in: (1) identifying its perceived value and deficits for enhanced recovery; (2) modifying current education practices to address educational deficits; and (3) evaluating these changes for preparing patients to enhance their recovery. Design: Qualitative study of three cycles of action research using mixed methods within a 24-month naturalistic enquiry to identify, implement and evaluate changes through observations, questionnaires, semistructured longitudinal interviews, focus groups and documentation review. Setting: A UK 1200-bed National Health Service (NHS) hospital providing colorectal surgery in a small city in a rural county. Participants: Ninety-sevenpatients having colorectal surgery, 19 carers and 22 clinical staff. Rresults: Themes identified were: (1) knowledge and engagement; (2) situated understanding and confidence building; and (3) partnership and proactive involvement in enhancing recovery. All patients articulated needs to prepare mentally and physically to plan for colorectal surgery and rehabilitation. Patients and carers wanted to counter uncertainty about medical procedures: likely bodily changes, recovery timescales and future. They therefore sought as much personalised, relevant information as possible about their disease, planned surgery and recovery. Staff implemented preoperative education to more specifically inform and respond multimodally to individual needs. Conclusions: Patients wanted to be proactively involved in managing their recovery to re-engage with their everyday lives. Preoperative education supported this through developing patients' situated understanding of hospital and bodily processes related to colorectal surgery. Situated understanding was achieved through educational product to give knowledge and processes promoting engagement. Multimodal, comprehensive and timely preoperative education on the whole patient pathway facilitates active engagement. Situated understanding increased patients' confidence to work in partnership with healthcare professionals and proactively self-manage recovery

    Changing energy profiles and consumption patterns following electrification in five rural villages, South Africa

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    Following the democratic transition in South Africa in the early 1990s the government has implemented a widespread electrification programme, as well as introduced a free basic electricity allowance as a means of poverty alleviation. Yet there are limited longitudinal studies on the impacts of the introduction of electricity on the patterns of household energy use, and even more so in the neglected rural sector. This study reports on the patterns of household energy use in five rural settlements in 1991 and again in 2002. Results indicate a changing pattern of energy use for lighting and powering entertainment appliances, more specifically from dry-cell batteries and paraffin to electricity. Yet for thermal needs, most notably cooking, fuelwood has remained the most widespread fuel, and the amount used per month has not changed, despite increasing scarcity of wood in the local environment. There has been an increase in the proportion of households purchasing fuelwood as opposed to collecting their own. Overall, the mean total number of fuel types used per household has increased, indicating that electricity is simply viewed as an additional energy, rather than an alternative. Yet, electricity accounted for approximately 60% of expenditure on energy sources in 2002, despite the government's policy of a free basic allowance of 5–6 kWh per month. This has implications for energy supply costing, as well as the poverty alleviation dimensions of the whole programme

    Hydropower plans in eastern and southern Africa increase risk of concurrent climate-related electricity supply disruption

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    Hydropower comprises a significant and rapidly expanding proportion of electricity production in eastern and southern Africa. In both regions, hydropower is exposed to high levels of climate variability and regional climate linkages are strong, yet an understanding of spatial interdependences is lacking. Here we consider river basin configuration and define regions of coherent rainfall variability using cluster analysis to illustrate exposure to the risk of hydropower supply disruption of current (2015) and planned (2030) hydropower sites. Assuming completion of the dams planned, hydropower will become increasingly concentrated in the Nile (from 62% to 82% of total regional capacity) and Zambezi (from 73% to 85%) basins. By 2030, 70% and 59% of total hydropower capacity will be located in one cluster of rainfall variability in eastern and southern Africa, respectively, increasing the risk of concurrent climate-related electricity supply disruption in each region. Linking of nascent regional electricity sharing mechanisms could mitigate intraregional risk, although these mechanisms face considerable political and infrastructural challenges
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