1,721,225 research outputs found
Do British wind generators behave strategically in response to the Western Link interconnector?
Full text linkIn Britain, the key source of renewable generation is wind, most abundant on the west coast of
Scotland, where there is relatively little demand. For this reason, an interconnector, the Western Link,
was built to take electricity closer to demand. When the Link is operating, payments by National Grid
to constrain wind farms not to produce will be lower, we may predict, since fewer or less restrictive
constraints need be imposed. But the Link has not been working consistently. We empirically estimate
the link’s value. Focusing on the three most recent episodes of outage, starting on 4th May 2018 up
to 25th September 2019, our essential approach is to treat these outages as a natural experiment using
hourly data. Our results reveal that the Link had an important role in costs saved and price constrained
and MWh curtailed reductions. We estimate a cost-saving of almost £30m. However, the saving
appears to drop over time, so we investigate wind farms’ behavior. We find that wind farms behave
strategically since the accuracy of wind forecasting depends on the relevant prices impacting their
earnings
Organising Competition for the Market
No full textWe study competition for the market in a setting where incumbents (and, to a lesser extent, neighbouring incumbents) benefit from a cost or information advantage. We first compare the outcome of staggered and synchronous tenders, before drawing the implications for market design. We find the timing of tenders interrelates with the likelihood of monopolisation. For high incumbency advantages and/or discount factors, monopolisation is expected, in which case synchronous tendering is preferable as it strengthens the pressure that entrants exercise on the monopolist. For low incumbency advantages and/or discount factors, other firms remain active, in which case staggered tendering is preferable as it maximises competitive pressure coming from the other firms. We use bus tendering in London to illustrate our insights and draw policy implications
Maintaining competition in recurrent procurement contracts : a case study on the London bus market
Full text linkUnder recurrent procurement, the awarding of a contract to a firm may put it in an advantageous position in future tenders, which may reduce competition over time. The objective of this paper is to study the dynamics of competition for tendered contracts, focusing on factors that may generate incumbent advantage. Particular attention is given to learning economies, sunk costs of entry and switching costs for the procurer. The paper then applies these insights to analyse empirically the evolution of competition in the market for local bus services in London
Analyzing the Potential Economic Value of Energy Storage
Full text linkThis paper examines the commercial opportunities for electrical energy storage, taking market prices as given and determining the extent to which a strategy of arbitrage across the day, buying at the lowest price times at night and selling at the highest price times during the early evening, and relying on price forecasts one day-ahead generates profits in the British context. The paper sets out the potential problems as the market moves to absorb increasing amounts of wind, then char-acterises the nature of prices, which reveals the importance of a strategy in which power is absorbed into store for a relatively few hours of the day and discharged over a relatively few hours. It argues that additional incentives may need to be put into place in order to render storage over relatively longer periods more attractive and to deliver broader social benefits which are unlikely to be generated and captured as a result of purely commercial considerations
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
A vision of the European energy future? : the impact of the German response to the Fukushima earthquake
Full text linkThe German response to the Fukushima nuclear power plant incident was possibly the most significant change of policy towards nuclear power outside Japan, leading to a sudden and very significant shift in the underlying power generation structure in Germany. This provides a very useful natural experiment on the impact of increasing proportions of renewable compared to conventional fuel inputs into power production, helping us to see how changed proportions in future as a result of policy moves in favour of renewables are likely to impact. We find through quasi-experimental exploration of a modified demand-supply framework that despite the swift, unpredicted change, the main impact was a significant increase in prices, partly caused by more frequent situations with unilateral market power. The price impact was also most significant in off-peak hours leading to changed investment incentives. There were no appreciable quantity effects on the market, such as power outages, contrary to some views that the impacts would be significant. Furthermore, we find the sudden and unilateral phase-out decision by the German government has significantly affected electricity prices and thus competitiveness in neighbouring countries
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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