1,720,971 research outputs found
Using the experience curve to analyze the cost development of the combined cycle gas turbine
No full textAnalyzing technological change using experience curves - a study of the combined cycle gas turbine
No full textThe aim of this thesis was to analyze and discuss the use of experience curves as a possible instrument for assessing future developments of a specific energy technology: the combined cycle gas turbine (CCGT). The CCGT technology is expected to figure prominently in future energy systems. In addition, assessing the future price developments of the CCGT technology provides an indication of the price levels that emerging technologies, e.g. renewable energy technologies, will have to reach in order to compete with it.Experience curves describe the observed phenomenon that the cost of a product decreases and/or performance increases by a certain percentage every time cumulative experience doubles. Cost is seldom publicly available and price is often used as a proxy for cost. Doing so introduces market behavior into the experience curve, which can — unless it is possible to screen for — mask the actual experience effect.The major determinants of future electricity-generation costs for the CCGT technology — specific investment price, thermal efficiency and natural-gas price — were investigated using experience curves. It was concluded that experience curves were efficient for analyzing the developments of specific investment price and thermal efficiency. The experience curve did not prove to be a feasible method for projecting future natural-gas prices since no correlation between price and experience could be established. The implications of the expected developments for the future costs of generating electricity from CCGT plants were also discussed
Using the experience curve to analyze the cost development of the combined cycle gas turbine
No full textAnalyzing technological change in low carbon power generation
No full textIn order to mitigate climate change while satisfying the growing global electricity demand, technological change within the power generating system is crucial. New low carbon technologies need to replace the current more carbon-intensive options. Promoting this change – at the necessary pace – requires policy instruments; creating efficient policy instruments requires a comprehensive understanding of the dynamics of technological change and current trends.
This four-paper thesis addresses the development, deployment, and diffusion of low carbon power generating technologies. The purpose is to better understand the drivers behind technological change, to explore current trends and assess future developments, and to consider the range of impacts of policy instruments in this context. Paper I uses experience curves to analyze the historical development of a technology expected to play a prominent role in future power generating systems, the combined cycle gas turbine. The results indicate that the rapid price decrease observed at the time rather reflected a temporary market behavior than an underlying production cost decrease. Analysis of other factors, e.g., technical performance improvements is an important complement to economic improvement analysis. Paper II investigates the deployment and diffusion of CO2-efficient power generating technologies in developed and developing countries. The results demonstrate that historical CO2-efficiencies tend to converge globally toward more efficient technologies. This suggests that if developments of new low carbon technologies are induced by, e.g., imposing stringent CO2 constraints on developed countries, these technologies will likely diffuse to regions with less stringent climate policies, e.g., developing countries, leading to additional CO2 reductions. Paper III explores the implications of international carbon emission trading for the development and deployment of advanced power generating technologies. A cost-optimization energy system model is applied using experience curves to endogenously model technological change. The results indicate that in general inter-regional trading provides stronger incentives for improvements in fossil-based technologies than for deploying advanced renewable technologies. However, technological change is mainly influenced by the level of future emission limits and by whether these levels are known well in advance. The results also stress the importance of early markets for new technologies, as early investments may significantly influence future technology trajectories. Paper IV analyzes a potential early market for the emerging renewable energy technology, biomass integrated gasification combined cycle (BIGCC). Data from a plausible reference market, the Indian sugarcane industry, is used in the analysis applying experience curves in future cost development modeling. The results indicate a large potential for cost reductions, if learning opportunities are provided, but additional financial support is required to make the technology commercially viable. The Clean Development Mechanism (CDM), using a project-by-project approach and at current carbon price levels, is likely to be sufficient to induce investments in the BIGCC technology to promote deployment and diffusion only once other measures have provided the initial support to create markets
Analyzing technological change using experience curves - a study of the combined cycle gas turbine
No full textThe aim of this thesis was to analyze and discuss the use of experience curves as a possible instrument for assessing future developments of a specific energy technology: the combined cycle gas turbine (CCGT). The CCGT technology is expected to figure prominently in future energy systems. In addition, assessing the future price developments of the CCGT technology provides an indication of the price levels that emerging technologies, e.g. renewable energy technologies, will have to reach in order to compete with it.Experience curves describe the observed phenomenon that the cost of a product decreases and/or performance increases by a certain percentage every time cumulative experience doubles. Cost is seldom publicly available and price is often used as a proxy for cost. Doing so introduces market behavior into the experience curve, which can — unless it is possible to screen for — mask the actual experience effect.The major determinants of future electricity-generation costs for the CCGT technology — specific investment price, thermal efficiency and natural-gas price — were investigated using experience curves. It was concluded that experience curves were efficient for analyzing the developments of specific investment price and thermal efficiency. The experience curve did not prove to be a feasible method for projecting future natural-gas prices since no correlation between price and experience could be established. The implications of the expected developments for the future costs of generating electricity from CCGT plants were also discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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