Uncertainty handling in fault tree based risk assessment: State of the art and future perspectives

YesRisk assessment methods have been widely used in various industries, and they play a significant role in improving the safety performance of systems. However, the outcomes of risk assessment approaches are subject to uncertainty and ambiguity due to the complexity and variability of system behaviour, scarcity of quantitative data about different system parameters, and human involvement in the analysis, operation, and decision-making processes. The implications for improving system safety are slowly being recognised; however, research on uncertainty handling during both qualitative and quantitative risk assessment procedures is a growing field. This paper presents a review of the state of the art in this field, focusing on uncertainty handling in fault tree analysis (FTA) based risk assessment. Theoretical contributions, aleatory uncertainty, epistemic uncertainty, and integration of both epistemic and aleatory uncertainty handling in the scientific and technical literature are carefully reviewed. The emphasis is on highlighting how assessors can handle uncertainty based on the available evidence as an input to FTA

Integration of the environmental management aspect in the optimization of the design and planning of energy systems

The increasing concerns regarding the environmental pollution derived from anthropogenic activities, such as the use of fossil fuels for power generation, has driven many interested parties to seek different alternatives, e.g. use of renewable energy sources, use of “cleaner” fuels and use of more effective technologies, in order to minimize and control the quantity of emissions that are produced during the life cycle of conventional energy sources. In addition to these alternatives, the use of an integrated procedure in which the environmental aspect will be taken into account during the design and planning of energy systems could provide a basis on which emissions reduction will be dealt with a life cycle approach. The work presented in this paper focuses on the examination of the possibilities of integrating the environmental aspects in the preliminary phase of the conventional design and planning of energy systems in conjunction with other parameters, such as financial cost, availability, capacity, location, etc. The integration of the environmental parameter to the design is carried out within a context where Eco-design concepts are applied. Due to the multi-parameter nature of the design procedure, the tools that are used are Life Cycle Analysis and Multi-criteria Analysis. The proposed optimization model examines and identifies optimum available options of the use of different energy sources and technologies for the production of electricity and/or heat by minimizing both the financial cost and the environmental impacts, with regard to a multiple objective optimization subject to a set of specific constraints. Implementation of the proposed model in the form of a case study for the island of Rhodes in Greece revealed that an optimized solution both cost and environmental-wise, would be an almost balanced participation of renewables and non-renewable energy sources in the energy mix

Perspectives on hydropower’s role to balance non-regulated renewable power production in Northern EuropeReport on the CEDREN workshop, Düsseldorf, 15-16 December 2010

This report summarizes the discussions during the CEDREN workshop ‘Perspectives on hydropower’s role to balance non-regulated renewable power production in Northern Europe’. The workshop was hosted by Statkraft Markets GmbH in Düsseldorf, Germany, 15-16 December 2010. The purpose of the workshop was to discuss opportunities and challenges in the development of new hydropower capacities in Norway, for balancing non-regulated renewable power production in Northern Europe. The workshop provided a meeting and discussion arena for important actors that are and will be involved in the future decision making process in Norway and Germany: power generation and grid companies, authorities and research communities. The discussions and reference studies presented during the workshop will be used as basis for future scenario work in CEDREN. Workshop participants: Statkraft Markets GmbH , EnBW AG, 50Hertz Transmission , Statnett SF, THEMA Consulting Group , Fraunhofer IWES , University of Flensburg , Energy Norway, NTNU, SINTEF Energy ResearchpublishedVersio

Decision Aid for Planning Local Energy Systems : Application of Multi-Criteria Decision Analysis

Planning is what sustains an energy system. It is a process of analysis and ongoing decision making about what resources and energy technologies to use when supplying energy to society. This research focuses on integrated energy systems, i.e. systems that are comprised of several energy carriers – electricity, gas, hot water - and energy distribution networks. The planning of these kinds of systems is a complex process, influenced by many factors, among which the most important are the availability of energy resources and the competition between different energy carriers in satisfying energy demand. During the last 10-20 years significant changes have taken place on the world energy scene, which have important implications for energy planning. Two main factors have triggered these changes. The first factor is the immediate need to address environmental changes or more generally, to take measures that are sustainable in the long run. Sustainability can be defined in many ways and in relation to different issues such as economic and ecologic development, reduction of greenhouse gases, responsible use of natural resources, social equity, etc. In recent years, an increased awareness of these issues has been observed at all levels of the society. The second factor is the deregulation of national energy sectors in more than 50 countries. This process brought changes in the ownership of different parts of the formerly integrated energy systems. New business opportunities were created in power generation, wholesale power/gas trading and energy retailing, while the energy infrastructures remained state owned or/and under regulatory control. The newly created energy markets (many of them international) have attracted both new players (power, oil and gas companies and financial institutions) together with the old ones (integrated utilities). In parallel with this vertical separation of national energy sectors, recent studies have shown a tendency for horizontal integration at the regional/company level. For instance, in order to reduce their overall business risk, companies prefer to participate in several segments of the energy value chain (in both regulated and non-regulated activities), and often across more than one fuel commodity, such as gas and electricity or district heating. In this context, the competition between different energy carriers in satisfying the end-use energy demand became obvious in economic as well as in technological and environmental terms. Traditionally, in integrated planning, this competition did not play a big role, since the same state entity made decisions at both national and regional levels. However, in the post-deregulation era it is no longer obvious who the planner is. In many cases, planning decision at local levels involve at least three main interest groups: energy companies (and/or other investors), the state and the local community. This thesis is motivated by the need to help planners to cope with the changes in concepts and values concerning the planning of local energy supply systems. This thesis has two aims. The first aim is to improve the understanding of what planning of local systems implies and how such a process can be structured. The second aim is to contribute to the development of decision support methodologies and tools that can cope with the needs in planning. For this purpose, the use of energy modelling and Multi- Criteria Decision Analysis has been studied

Task 16.2.2 Hydro Potential and Barriers

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Reinvestment strategy making for distribution networks

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OVERALL CHALLENGES AND RECOMMENDATIONS CONCERNING THE INTEGRATION OF SMALL SCALE HYDRO IN MV DISTRIBUTION NETWORKS

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R RI IS SK K--B BA AS SE

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Application of Bayesian Networks in Distribution System Risk Management

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Risk Based Decision for Reinvestments in Distribution Systems

This paper illustrates the challenges associated with risk assessment for reinvestments decisions. A holistic framework for risk assessment in electricity distribution systems will be described first and then used to structure the analysis and decision making in a case study concerning cable reinvestment. These decisions are generally multi criteria decisions, including risks related to e.g.; economy, environment, reputation, safety and quality of supply. The paper describes the use of different types of decision support tools used to aid reinvestment decision making in electricity distribution systems, with emphasis on multi criteria decision analysis (MCDA).acceptedVersio