M.Ed. (Computer-Based Education) / Please refer to full text to view abstract

The entire diploma thesis analyses causes, consequences and repercussions of an electricity grid network blackout and its impact to the respective consumers. Remarkable blackouts recorded since 1965 are briefly described and basic available information is considered. The grid standard fixing measures and electricity delivery priorities are characterized. The thesis also pays attention to entire Czech Republic grid availability and its blackout endurance as well as to its robustness within last several years. Indirect Fukushima event influence to the Czech Republic electricity system is mentioned. The main part of the thesis comprises of four big European grid blackouts causes and consequences, their comparison to each other and to the Dukovany nuclear power plant grid blackout drill scenario. The preventive and standard corrective measures against blackouts are pointed out.

Thesis is submitted in partial fulfilment for the degree of Master of Science in Building (Property Development and Management) to the Faculty of Engineering and the Built Environment, School of Construction Economics and Management at the University of the Witwatersrand, Johannesburg, 2017 / South Africa’s electricity demand, over exceeds its’ supply capability; this in-turn affects a myriad of developmental factors namely: economic growth, business growth prospects, property development, the environment, as well as society as a whole. The traditional (fossil fuel generated) centralized electricity production model, has proven to be insufficient in terms of production capability as well as infrastructure expansion. This has in-turn presented an opportunity for real estate (more specifically listed regional and super-regional retail real estate) to capture a niche gap in the electricity generation market, that of becoming: decentralized renewable electricity generating production plants, that can become self-sufficient and sustainable, while plugging excess electricity back into the national electricity grid; these would in-turn form a network of individual power plants, that can contribute towards the national electricity grid through a smart-grid system, regulated by Nersa and monitored by Eskom. Structured interviews with industry professionals were captured through audio-recordings; the conversations were then author transcribed through pattern emergence as an interpretation tool, analyzed, and the findings documented in this research report. The major findings illustrated that: there were sufficient incentives from the government that promoted electricity generating real estate; feed-in tariffs were being explored within certain municipalities; within the listed property sector, portfolio greenness was becoming more and more important in commercial property development as well as portfolio sustainability; and technological price-parity had been reached within South Africa (meaning that the justification for utilizing the conventional electricity extractive development strategy, rather than the renewable electricity generating strategy, could no-longer be used as an excuse, due to both methods working out to relatively the same costs overall). Key recommendations where that: the self-sufficiency and electricity generation drive should come mainly from tenants, who could then place pressure on the landlords, who would then begin developing in a generation focused way rather than a cost-saving and low cost method; municipalities needed to look at other revenue generating schemes, as an intervention such as this one would see a possible loss of revenue due to a smart-grid system; and developers needed to begin thinking outside of the box, and creating wealth not only in monetary terms, but also in sustainability terms. It was concluded that, as much as this intervention could work in the long-run, it would face a few immediate challenges in the short to medium run, namely: grid connection approval, IPP (Independent power producer) approval, the challenges of shopping mall design with a huge dependence on HVAC / mechanical ventilation which uses tremendous amounts of electricity, as well as the electricity consumption of a regional & super regional retail centre almost being on par with the potential electricity that could be produced. With all that having been mentioned, this intervention would be a five to ten year development strategy that could be worked towards, and would create a new benchmark for listed commercial regional & super-regional retail developments within Gauteng. / MT2018

abstract: Energy poverty is pervasive in sub-Saharan Africa. Nigeria, located in sub-Saharan West Africa, is the world's seventh largest oil exporting country and is a resource-rich nation. It however experiences the same levels of energy poverty as most of its neighboring countries. Attributing this paradox only to corruption or the "Dutch Disease", where one sector booms at the expense of other sectors of the economy, is simplistic and enervates attempts at reform. In addition, data on energy consumption is aggregated at the national level via estimates, disaggregated data is virtually non-existent. Finally, the wave of decentralization of vertically integrated national utilities sweeping the developing world has caught on in sub-Saharan Africa. However, little is known of the economic and social implications of these transitions within the unique socio-technical system of the region's electricity sector, especially as it applies to energy poverty. This dissertation proposes a complex systems approach to measuring and mitigating energy poverty in Nigeria due to its multi-dimensional nature. This is done via a three-fold approach: the first section of the study delves into causation by examining the governance institutions that create and perpetuate energy poverty; the next section proposes a context-specific minimum energy poverty line based on field data collected on energy consumption; and the paper concludes with an indicator-based transition management framework encompassing institutional, economic, social, and environmental themes of sustainable transition within the electricity sector. This work contributes to intellectual discourse on systems-based mitigation strategies for energy poverty that are widely applicable within the sub-Saharan region, as well as adds to the knowledge-base of decision-support tools for addressing energy poverty in its complexity. / Dissertation/Thesis / Doctoral Dissertation Sustainability 2015

Electrical power system is an essential technical system intended to power supply. The power drain is still increasing and it is possible to suppose rising trend in the future. Because of this fact there are installed new power sources into the system, so it is important to know manners and parameters of the electricity supply system as well as the new power sources which we are connecting to the grid. Due to these reasons, the electricity supply system is being simplified and described as the steady state operation with different numerical methods. To dimension a connection of the new power source to the grid, it has to be determined short-circuit conditions too.

Electricity is the most preferred source of energy, because of its quality and convenience of usage. It is probably one of the most vital infrastructural inputs for economic development of a country. Indeed it is the fulcrum which can leverage the future pace of growth and development. These reasons have made the electric power industry one of the fastest growing sectors in most developing countries and particularly in India. Therefore it is not surprising to observe the economic growth of a country being related to the increase in electricity consumption. In India, the growth rate of demand for power is generally higher than that of Gross Domestic Product (GDP). However, to achieve this kind of growth in electricity supply, the capital investments required are very huge. Even though the electricity sector generally gels a major share in the budgetary allocations in India, this is inadequate to add the required quantum of new generation capacity to keep pace with the increase in demand for electricity. Additional constraints like capital scarcity in the public sector, lack of enthusiasm among the private and foreign investors, and strong opposition from the environmentalists have further contributed to this slow pace of new generating capacity addition. This has resulted in severely constrained systems in India. The main focus of the present research work is on the development of an integrated approach for electricity planning using a mathematical modeling framework in (he context of resource constrained systems. There are very few attempts in the literature to integrate short, medium and long term issues in electricity planning. This is understandable from the point of view of unconstrained electricity systems where this type of integration is unnecessary since such systems have a luxury of surplus capacity to meet the current demand and capacity additions are required only for meeting predicted future increase in demand. However, in the case of constrained electricity systems, which are characterized by shortages, this kind of integration is very essential. These systems have to manage with inadequate capacity in the present, plan capacity additions to bridge the existing gap and to meet future increase in demand, and always explore the possibility of adding capacity with short gestation period. The integrated approach is expected to achieve effective supply-demand matching on a continuous basis encompassing both the short term and long term horizons. To achieve this, we have considered three alternatives- existing supply, new supply and non-supply (rationing) of electricity. The electricity system of the state of Karnataka, which is severely constrained by both limited capital and energy resources, has been selected for this purpose. As a first step, the supply and demand situation has been studied in the context of resource constraints. In terms of supply, both existing and future additions are studied in detail with respect to the potential created, generation types, import potential, technical constraints, energy and power shortages, planned and proposed capacity additions by both public and private sectors, etc. The demand patterns have been studied by introducing a new concept of "Representative Load Curves (RLCs)". These RLCs are used to model the temporal and structural variations in demand for electricity. Also, appropriate non-supply options (rationing measures) for effective management of shortages are identified. Incorporating this information, an integrated mathematical model, which is expected to generate a target plan for a detailed generation scheduling exercises and a requirement plan for a regular generation expansion planning, has been developed. The other important alternative "Demand-Side-Management (DSM)", which could be considered as an effective option to achieve efficient supply-demand matching has not been included in the present research work. The major reason for not including the DSM alternatives is due to the difficulty in integrating these in the modelling approach adopted here. In the present approach we have used typical daily load curves (RLCs) to represent the demand for electricity. These are aggregate load curves and do not contain any sector-wise or end-use-wisc details. On the other hand, DSM alternatives are end-use focused. To incorporate DSM alternatives, we should have information on end-usc-wisc power demand (kW or MW), savings potential, time-of-use, etc. For this purpose it may be required to have end-use-wisc daily load curves. This information is not available and a separate detailed survey may be required to generate these load curves. This, we felt, is out of the scope of this present research work and a separate study may be required to do this. Therefore, we restricted our focus to supply planning alone. A detailed literature review is conducted to understand different types of modeling approaches to electricity planning. For the present study, however, the review of literature has been restricted to the methods of generation expansion planning and scheduling. In doing so, we attempted to bring out the differences in various approaches in terms of solution methods adopted, alternatives included and modifications suggested. Also, we briefly reviewed the literature on models for power and energy rationing, because management of shortages is an important aspect of the present study. Subsequently, a separate section is devoted to present an overview of the non-supply of electricity and its economic impacts on the consumers. We found that the low reliability of the electrical system is an indicator of the existence of severe shortages of power and energy, which cause non-supply of electricity to the consumers. The overview also presented a discussion on reasons for non-supply of electricity, and the types of non-supply options the utilities adopt to over come these shortages. We also attempted to explain what we mean by non-supply of electricity, what are its cost implications, and the methods available in the literature to estimate these costs. The first objective of the research pertains to the development of a new approach to model the varying demand for electricity. Using the concept of Representative Load Curves (RLCs) we model the hourly demand for a period of four years, 1993-94, 1994-95, 1995-96 and 1996-97, to understand the demand patterns of both unconstrained and constrained years. Multiple discriminant analysis has been used to cluster the 365 load curves into nine RLCs for each of the four years. The results show that these RLCs adequately model the variations in demand and bring out the distinctions in the demand patterns existed during the unconstrained and constrained years. The demand analysis using RLCs helped to study the differences in demand patterns with and without constraints, impacts of constraints on preferred pattern of electricity consumption, success of non-supply options in both reducing the demand levels and greatly disturbing the electricity usage patterns. Multifactor ANOVA analyses are performed to quantify the statistical significance of the ability of the logically obtained factors in explaining the overall variations in demand. The results of the ANOVA analysis clearly showed that the considered factors accounted for maximum variations in demand at very high significance levels. It also brought out the significant influence of rationing measures in explaining the variations in demand during the constrained years. Concerning the second objective, we explained in detail, the development of an integrated mixed integer-programming model, which we felt is appropriate for planning in the case of resource constrained electricity systems. Two types of integrations are attempted (i) existing supply, non-supply and new supply options for dynamically matching supply and demand, (ii) operational and strategic planning in terms of providing target plans for the former and requirement plans for the latter. Broadly, the approach addresses the effective management of existing capacity, optimal rationing plan to effectively manage shortages and rationally decide on the new capacity additions both to bridge the existing gap between supply and demand, and to meet the future increases in demand. There is also an attempt to arrive at an optimal mix of public and private capacity additions for a given situation. Finally, it has been attempted to verify the possibility of integration of captive generation capacity with the grid. Further, we discussed in detail about the data required for the model implementation. The model is validated through the development of a number of scenarios for the state of Karnataka. The base case scenario analyses are carried out for both the unconstrained and constrained years to compare the optimal allocations with actual allocations that were observed, and to find out how sensitive are the results for any change in the values of various parameters. For the constrained years, a few more scenarios are used to compare the optimal practice of managing shortages with to what has been actually followed by the utility. The optimal allocations of the predicted demand to various existing supply and non-supply options clearly showed that the actual practice, reflected by the actual RLCs, are highly ad hoc and sub-optimal. The unit cost comparisons among different scenarios show that the least cost choice of options by the utility does not necessarily lead to good choices from the consumers’ perspective. Further, a number of future scenarios are developed to verify the ability of the model to achieve the overall objective of supply-demand matching both in the short and long term. For this purpose both the short horizon annual scenarios (1997-98 to 2000-01) and long horizon terminal year scenarios (2005-06 and 2010-11) are developed assuming capacity additions from only public sector. Overall, the results indicated that with marginal contributions from non-supply options and if the public sector generates enough resources to add the required capacity, optimal matching of supply and demand could be achieved. The scenario analyses also showed that it is more economical to have some level of planned rationing compared to having a more reliable system. The quantum of new capacity additions required and the level of investments associated with it clearly indicated the urgent need of private sector participation in capacity additions. Finally, we made an attempt to verify the applicability of the integrated model to analyse the implications of private sector participation in capacity additions. First, a number of scenarios are developed to study the optimal allocations of predicted hourly demand to private capacity under different situations. Secondly, the impacts of privatisation on the public utility and consumers are analysed. Both short term and long term scenarios are developed for this purpose. The results showed the advantage of marginal non-supply of electricity both in terms of achieving overall effective supply-demand matching and economic benefits that could be generated through cost savings. The results also showed the negative impacts of high guarantees offered to the private sector in terms of the opportunity costs of reduced utilization of both the existing and new public capacity. The estimates of unit cost of supply and effective cost of supply facilitated the relative comparison among various scenarios as well as finding out the merits and demerits of guarantees to private sector and non-supply of electricity. The unit cost estimates are also found to be useful in studying the relative increase in electricity prices for consumers on account of privatization, guarantees and reliable supply of electricity. Using the results of scenario analyses, likely generation expansion plans till the year 2010-11 are generated. The analyses have been useful in providing insights into fixing the availability and plant load factors for the private sector capacity. Based on the analysis, the recommended range for plant utilization factor is 72.88 - 80.57%. The estimated generation losses and the associated economic impacts of backing down of existing and new public capacity on account of guarantees offered to private sector are found to be significantly high. The analyses also showed that the backing down might take place mainly during nights and low demand periods of monsoon and winter seasons. Other impacts of privatization that studied are in terms of increased number of alternatives for the utility to buy electricity for distribution and the associated increase in its cost of purchase. Regarding the consumers, the major impact could be in terms of significant increase in expected tariffs. The major contributions of this thesis are summarized as follows: i. An integrated approach to electricity planning that is reported here, is unique in the sense that it considers options available under various alternatives, namely, existing supply, non-supply and new supply. This approach is most suited for severely constrained systems having to manage with both energy and capital resource shortages. ii. The integration of operational and strategic planning with coherent target plans for the former and requirement plans for the latter bridges the prevailing gap in electricity planning approaches. iii. The concept of Representative Load Curves (RLCs), which is introduced here, captures the hourly, daily and seasonal variations in demand. Together, all the RLCs developed for a given year are expected to model the hourly demand patterns of that year. These RLCs are useful for planning in resource constrained electricity systems and in situations where it is required to know the time variations in demand (e.g. supply-demand matching, seasonal scheduling of hydro plants and maintenance scheduling). RLCs are also useful in identifying the factors influencing variations in demand. This approach will overcome the limitations of current method of representation in the form of static and aggregate annual load duration curves. iv. A new term, "non-supply of electricity" has been introduced in this thesis. A brief overview of non-supply presented here includes reasons for non-supply, type of non-supply, methods to estimate cost of non-supply and factors influencing these estimates. v. The integrated mixed integer programming model developed in the study has been demonstrated as a planning tool for- • Optimal hourly and seasonal scheduling of various existing supply, non-supply and new supply options • Estimation of supply shortages on a representative hourly basis using the information on resource constraints • Effectively planning non-supply of electricity through appropriate power/energy rationing methods • Estimation of the need for the new capacity additions both to bridge the existing gap and to take care of increase in future demand levels • Optimal filling of gaps between demand and supply on a representative hourly basis through new supply of electricity • Optimally arriving at the judicious mix of public and private capacity additions • Studying the impacts of private capacity on the existing and new public sector capacity, and on the consumers • Optimally verifying the feasibility of integrating the captive generation with the total system vi. The demand analysis using RLCs helped to bring out the differences in demand patterns with and without constraints, impacts of constraints on preferred pattern of electricity consumption, success of non-supply options in both reducing the demand levels and greatly disturbing the electricity usage patterns. Multifactor ANOVA analyses results showed that the logically obtained factors accounted for maximum variations in demand at very high significance levels. vii. A comparison of optimal (represented by optimal predicted RLCs) and actual (reflected by actual RLCs) practices facilitated by the model showed that the actual practice during constrained years is highly ad hoc and sub-optimal. viii. The results of the scenario analyses showed that it is more economical to have some amount of planned rationing compared to having a more reliable system, which does not allow non-supply of electricity. ix. The scenarios, which analysed the impacts of high guarantees offered to the private sector, showed the negative impacts of these in terms of reduced utilization of both the existing and new public capacity. x. Generation expansion plans till the year 2010-11 are developed using the results of various kinds of scenario analyses. Two groups of year-wise generation expansion plans are generated, one with only public sector capacity additions and the other with private sector participation. xi. The impacts of privatization of capacity additions are studied from the point of view of the utility and consumers in terms of expected increase in cost of purchase of electricity and tariffs. xii. The analyses are also made for developing some insights into fixing the availability and plant load factors for the private capacity. Based on the analysis, the recommended range for plant utilization factor is 72.88 - 80.57%. We believe that the integrated approach presented and the results obtained in this thesis would help utilities (both suppliers and distributors of electricity) and governments in making rational choices in the context of resource constrained systems. The results reported here may also be used towards rationalization of Government policies vis-a-vis tariff structures in the supply of electricity, planning new generation capacity additions and effective rationing of electricity. It is also hoped that the fresh approach adopted in this thesis would attract further investigations in future research on resource constrained systems.

This thesis addresses the problems associated with security of the electricity supply in the UK. The British electricity supply industry has experienced a significant structural change. Competition has been brought into the electricity industry and a single wholesale electricity market of Great Britain has been established. The evolution of the British electricity market raises new challenges, such as improving the liquidity of wholesale markets and developing clean energy. The wholesale electricity prices are less transparent and trading arrangements are very complex in the British electricity market. In this thesis a fundamental model, called a stack model, has been developed in order to forecast wholesale electricity prices. The objective of the stack model is to identify the marginal cost of power output based on the fuel prices, carbon prices, and availability of power plants. The stack model provides a reasonable marginal cost curve for the industry which can be used as an indicator for the wholesale electricity price. In addition, the government's targets for climate change and renewable energy bring new opportunities for wind energy. Under the large wind energy penetration scenario the security of the energy supply will be essential. We have modelled the correlations between wind speed data for a set of wind farms. The correlation can be used to measure the portfolio risk of the wind farms. Electricity companies should build their portfolio of wind farms with low or negative correlations in order to hedge the risk from the intermittency of wind. We found that the VAR(1) model is superior to other statistic models for modelling correlations between wind speeds of a wind farm portfolio.

O presente trabalho apresenta, primeiramente, o desenvolvimento e aplicação de uma Ferramenta de Apoio à Decisão (FAD), seguindo os conceitos de Sistemas de Informação (SI), para facilitar o acesso e visualização de informações técnicas estratégicas, e que possa compor um Sistema de Apoio à Decisão (SAD) que englobe o portfólio de informações necessárias para o planejamento da priorização de obras de investimento e expansão das redes de distribuição de energia. A FAD proposta realiza o tratamento de um grupo de dados relativos a incidência de interrupções de energia da rede de distribuição de uma concessionária do setor elétrico, de forma a disponibilizar as informações depuradas para auxílio na tomada assertiva de decisão para aplicação de recursos para execução de ações de manutenção em rede de distribuição. Em seguida, exibe a inclusão de uma função de análise, no aplicativo desenvolvido como Ferramenta de Apoio à Decisão (FAD), baseada na priorização multicriterial AHP (Analytic Hierarchy Process). A aplicação do método AHP indica as estações avançadas da concessionária que possuem prioridade para a aplicação de recursos que visam à execução de ações de manutenção em rede de distribuição para a melhoria nos indicadores de continuidades do fornecimento de energia. / This paper first introduces the development and application of a Decision Support Tool (FAD), following the concepts of Information Systems (IS), to facilitate the availability and visualization of strategic techniques information, and can compose a Decision Support System (DSS) that encompasses the entire portfolio of information needed for planning the prioritization of investment works and expansion of power distribution networks. The proposed FAD performs the treatment of a group of data on the incidence of power outages in the distribution of the electric utility industry network in order to provide information to aid in purified assertive decision making for application of resources for execution maintenance actions in the distribution network. Then displays the inclusion of an analysis function, the application developed as a Tool for Decision Support (FAD), multicriteria prioritization based on AHP (Analytic Hierarchy Process). The application of AHP method indicates the advanced utility stations that have priority for use of funds aimed at the implementation of maintenance actions in the distribution network to improve the indicators of continuity of power supply.

O presente trabalho apresenta, primeiramente, o desenvolvimento e aplicação de uma Ferramenta de Apoio à Decisão (FAD), seguindo os conceitos de Sistemas de Informação (SI), para facilitar o acesso e visualização de informações técnicas estratégicas, e que possa compor um Sistema de Apoio à Decisão (SAD) que englobe o portfólio de informações necessárias para o planejamento da priorização de obras de investimento e expansão das redes de distribuição de energia. A FAD proposta realiza o tratamento de um grupo de dados relativos a incidência de interrupções de energia da rede de distribuição de uma concessionária do setor elétrico, de forma a disponibilizar as informações depuradas para auxílio na tomada assertiva de decisão para aplicação de recursos para execução de ações de manutenção em rede de distribuição. Em seguida, exibe a inclusão de uma função de análise, no aplicativo desenvolvido como Ferramenta de Apoio à Decisão (FAD), baseada na priorização multicriterial AHP (Analytic Hierarchy Process). A aplicação do método AHP indica as estações avançadas da concessionária que possuem prioridade para a aplicação de recursos que visam à execução de ações de manutenção em rede de distribuição para a melhoria nos indicadores de continuidades do fornecimento de energia. / This paper first introduces the development and application of a Decision Support Tool (FAD), following the concepts of Information Systems (IS), to facilitate the availability and visualization of strategic techniques information, and can compose a Decision Support System (DSS) that encompasses the entire portfolio of information needed for planning the prioritization of investment works and expansion of power distribution networks. The proposed FAD performs the treatment of a group of data on the incidence of power outages in the distribution of the electric utility industry network in order to provide information to aid in purified assertive decision making for application of resources for execution maintenance actions in the distribution network. Then displays the inclusion of an analysis function, the application developed as a Tool for Decision Support (FAD), multicriteria prioritization based on AHP (Analytic Hierarchy Process). The application of AHP method indicates the advanced utility stations that have priority for use of funds aimed at the implementation of maintenance actions in the distribution network to improve the indicators of continuity of power supply.

Orientador: Jose Carlos de Souza Braga / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Economia / Made available in DSpace on 2018-08-09T20:22:52Z (GMT). No. of bitstreams: 1 AmaralFilho_JoseBonifaciodeSouza_D.pdf: 2626394 bytes, checksum: c6e3bbfd2e9421ef9fc7a39011ad2072 (MD5) Previous issue date: 2007 / Resumo: Este trabalho apresenta uma visão geral da reforma e evolução recente do setor elétrico brasileiro e mostra que, não obstante as mudanças já promovidas, alguns problemas não resolvidos e limitações estruturais apontam para dificuldades de suprimento e custos crescentes da energia elétrica. O trabalho mostra que o setor elétrico brasileiro passou por importantes transformações, após a crise financeira vivida pelas concessionárias estatais nos anos 80 e 90: a regulação setorial foi profundamente alterada desde 1993, uma grande parte das empresas estatais foi transferida para controle privado desde 1995, e uma consultoria internacional iniciou em 1996 um trabalho de apoio à re-estruturação setorial e desenho de um novo modelo a ser implementado, o que foi concluído em 1998. Em 2001 a reforma setorial ainda não havia sido completada quando a crise de oferta de eletricidade levou ao racionamento do consumo e à necessidade de revisão do modelo proposto. Em 2003, a nova administração federal reabriu as discussões sobre o modelo e novas mudanças foram implantadas em 2004, visando a segurança do abastecimento e a modicidade tarifária. Entretanto, a nova sistemática de expansão da geração ainda não está satisfatoriamente equacionada, especialmente no segmento livre do mercado, e o segmento regulado poderá ser afetado pela disputa pela energia existente, a par de uma tendência de elevação de preços do novo suprimento de energia / Abstract: This work presents an overview of reform and recent evolution of the Brazilian electric sector and shows that, in spite of the changes that have been already carried out, some problems still remain and structural limitations point to difficulties in supply and growing costs of electricity. The work shows that Brazilian electric sector experienced important changes, after the financial crisis that involved state owned utilities in the 80¿s and beginning of the 90¿s: regulation was deeply modified since 1993, a great number of state owned utilities was privatized since 1995, and international consultants initiated in 1996 a work to support the electric sector restructuring and the design of a new model to be implemented, which was concluded in 1998. In 2001, the reform had not yet been completed when electricity supply crisis irrupted and provoked rationing of consumption and the need to review the proposed model. A new federal administration reopened discussions in 2003 regarding the model and new changes were implemented in 2004, aiming at to secure the expansion of supply combined with tariff moderateness. The new systematic of expansion of electricity supply is not satisfactorily established yet, in special in the ¿free market¿ segment, and the ¿regulated market¿ segment can be affected by the dispute for existing energy, along with a tendency of prices of new supply to increase / Doutorado / Teoria Economica / Doutor em Ciências Econômicas