Evaluating the Robustness of Resource Allocations Obtained through Performance Modeling with Stochastic Process Algebra

Recent developments in the field of parallel and distributed computing has led to a proliferation of solving large and computationally intensive mathematical, science, or engineering problems, that consist of several parallelizable parts and several non-parallelizable (sequential) parts. In a parallel and distributed computing environment, the performance goal is to optimize the execution of parallelizable parts of an application on concurrent processors. This requires efficient application scheduling and resource allocation for mapping applications to a set of suitable parallel processors such that the overall performance goal is achieved. However, such computational environments are often prone to unpredictable variations in application (problem and algorithm) and system characteristics. Therefore, a robustness study is required to guarantee a desired level of performance. Given an initial workload, a mapping of applications to resources is considered to be robust if that mapping optimizes execution performance and guarantees a desired level of performance in the presence of unpredictable perturbations at runtime. In this research, a stochastic process algebra, Performance Evaluation Process Algebra (PEPA), is used for obtaining resource allocations via a numerical analysis of performance modeling of the parallel execution of applications on parallel computing resources. The PEPA performance model is translated into an underlying mathematical Markov chain model for obtaining performance measures. Further, a robustness analysis of the allocation techniques is performed for finding a robustmapping from a set of initial mapping schemes. The numerical analysis of the performance models have confirmed similarity with the simulation results of earlier research available in existing literature. When compared to direct experiments and simulations, numerical models and the corresponding analyses are easier to reproduce, do not incur any setup or installation costs, do not impose any prerequisites for learning a simulation framework, and are not limited by the complexity of the underlying infrastructure or simulation libraries

Improvements to transmission expansion planning and implementation :treating uncertainty in commercial operation dates and increasing aunction efficiency

Three proposals contributing to the electricity transmission expansion planning and implementation process are presented in this thesis. The first proposal refers to the use of combinatorial and simultaneous descending auctions to treat the exposure problem and increase the efficiency of multi-item transmission auctions. A simulation framework to quantify potential benefits of using these auctions protocols, for transmission companies and grid users, is proposed. The second proposal refers to an expansion planning methodology that explicitly accounts for uncertainties in facility implementation times while determining the capacity additions and their optimal implementation schedule. In the third proposal, principal-agent theoretic concepts are applied to develop a methodology for the optimal design of winner-selection and risksharing mechanisms, with the goal of managing uncertainties in implementation times of transmission facilities, when competitive processes are used to select the agents to which concessions to implement and operate these facilities are awarded. Classical optimization approaches, notably mixed-integer linear programming, are used in the mathematical formulations that underlie the simulation and analyses carried out for all three proposals; and qualitative conclusions aiming at aiding planners and regulators are drawn from the quantitative results of case studies.Esta tese apresenta três contribuições ao planejamento e implantação da expansão da transmissão. Primeiro, propõe-se usar leilões combinatórios e leilões descendentes simultâneos para tratar o problema da exposição em leilões multi-itens de concessões de transmissão, aumentando a eficiência destes leilões, e apresenta-se um arcabouço de simulação para quantificar os benefícios potencias do uso de tais protocolos. Segundo, propõe-se uma metodologia de planejamento da expansão que considera explicitamente incertezas em tempos de implantação de instalações da transmissão ao determinar as adições de capacidade e as datas de início de implantação de ativos. Terceiro, aplica-se conceitos da teoria do agente-principal para propor uma abordagem para otimizar o desenho de mecanismos de seleção do vencedor e de partilha de riscos, de modo a gerir incertezas em tempos de implantação de ativos, no contexto em que mecanismos competitivos são utilizados para selecionar os agentes a que contratos de transmissão implantação são concedidos. Para todas as três propostas, utiliza-se abordagens de otimização clássica, notadamente programação inteira linear mista, para a formulação matemática que subsidia simulações e análises; e retira-se dos resultados numéricos de estudos de casos conclusões qualitativas que subsidiem planejadores e reguladores

Exploring the governance of private finance for the electricity sector in sub-Saharan Africa

My dissertation is a paper style thesis, which contains the following chapters: an introduction; a research design; three chapters, each derived from a different successful peer reviewed policy paper (there were corrections applied to each of the original papers); and a discussion and conclusions section. My thesis aims to answer the following research question: ‘What aspects of governance deter private investors from financing large-scale electricity network infrastructure in sub-Saharan Africa?’ My methodology utilises a Hypothetico-deductive approach: which focuses on the impact of risk surrounding the private financing process, when applied to electricity infrastructure development in the sub-Saharan region. My sources for evidence are mixed and multidisciplinary; and my analysis principally applies a governance lens. This is an important topic, as it is over 20 years since the multilateral development community re-focused its policy surrounding the improvement of electricity access in sub-Saharan Africa (SSA), to one that places private sector financing at the centre of its strategy (which transpired during the leadership of the World Bank by James Wolfensohn in the 1990s). Yet according to a recently published report by the IEA: ‘despite being home to 17% of the world’s population, Africa currently accounts for just 4% of global power supply investment’ – suggesting a significant policy failure for over twenty years. With SSA’s population forecast to double by the UN by 2050, it is imperative that the development community understands why such a policy is gaining so little traction. Affordable and reliable energy access is crucial for the economic growth that such a rapid population increase will require. If it is not delivered, excessive environmental damage will otherwise occur, as the enlarging population will have to continue to rely on unsustainably biofuel sources for its energy needs (mostly wood – causing deforestation); and ever increasing social problems will ensue, due to accelerating competition for scarce resources by this ever-growing population. My first paper has two functions: firstly, to reformulate the relevance of risk within the academic research community as an obstruction to the private financing of new SSA electricity infrastructure development. Secondly, to confirm and classify those risks that can be found in the greater interdisciplinary literature, which would negatively influence a private, financier’s willingness to invest in this type of infrastructure. To do this, I firstly analysed a manageable five-year sample of literature surrounding three African countries with a notable body of academic literature: Kenya, Mozambique, and Tanzania. To create my sample, I systematically interrogated the two principle academic libraries of Scopus and the Web of Science, using key terms. My secondary analysis then digs deeper, by including further interdisciplinary literature not specific to the first sample, drawing from the Project Management, Finance, and Innovation academic disciplines – to identify and classify all relevant and likely risks. My second paper is theoretical and utilises three separate perspectives to deliver a holistic and inclusive governance picture, to answer the following research question: ‘What aspects of governance deter private investors from financing large-scale electricity network infrastructure in sub-Saharan Africa?’ These perspectives comprise: 1) Financial Investment Governance, the private sector investor’s perspective, which focuses on the rules and institutions (or lack of) that directly influence the financial investment environment in SSA. 2) Political Governance, the political economy perspective, which relate to the negative, indirect investment consequences resulting from the way that SSA governments govern; and 3) Technical System Governance, a ‘systems’ perspective, which encompasses how the standard structure and organisation of the wider electricity delivery system in each country in SSA, negatively impacts such investment. My third paper focuses on the impact of governance surrounding large-scale electricity infrastructure development (megaprojects), by empirically analysing six case studies located in South Africa. My guide for my fieldwork was the following research question: ‘What aspects of project governance are important, to prevent time delays and cost overruns, when building large scale electricity infrastructure in South Africa?’ This research question is relevant to my thesis’ primary interrogation theme, as the adherence to schedules and budgets are of central importance to successful private financing of such infrastructure. My discussion and conclusions section commences with an explanation for why the multilateral development community should persevere with their policy of promoting private financing of electricity infrastructure development, in SSA. I do this by first explaining why access to affordable and reliable electricity services in Africa is crucial for promoting the meaningful economic growth in the region. I then discuss why the alternatives to this policy, are less inclusive and more exploitive. I then use this positioning to frame my key findings from my research, which I then clarify. Finally, I discuss policy implications surrounding my findings and possible policy solutions