Do British wind generators behave strategically in response to the Western Link interconnector?

In 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

Scottish wind farms and the monetary incentives to switch off

Increased interconnection to bring the energy produced to more people and industries is important and so is reforming the payments system, write Mario Intini and Michael Waterso

Do British wind generators behave strategically in response to the Western Link interconnector?

In 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

Preliminary fluid-structure investigations on buffeting phenomenon of the Vulcain 2 nozzle

The transonic base-flow buffeting is an unsteady phenomenon during the ascent which produces high structural loads on the launcher propulsion system, especially on the nozzle. This phenomenon is a critical issue in the optimization of the future launch vehicles: in fact the attempts to improve the propulsive performances of the space vehicles are leading to the use of large area-ratio nozzles, which are more sensitive to the buffeting instabilities than the traditional ones. The purpose of this thesis is to perform preliminary investigations on the transonic buffeting of the Vulcain 2 nozzle, focusing in particular on the effects of this base-flow instability on the structure of this component. First of all, the Ariane 5 ECA (i.e. the launch vehicle on which is mounted the analysed nozzle) architecture and the Vulcain 2 engine have been described in Chapter 1. After a brief literature review on buffeting in Chapter 2 (useful also to derive the hypotheses and the data to be used as “references” for the models and the results of this thesis), the main procedures performed to obtain the different models (i.e. the fluid-dynamic and structural ones, carried out through STAR-CCM+® and ABAQUS® software respectively) have been detailed in Chapter 3. This last chapter lists also all the simplified assumptions considered in the realization of the previous models and in the “one-way” coupling process between the fluid-dynamic and the structural solvers. Then the results of the performed fluid-structure analyses have been collected and broadly commented in Chapter 4. Using the data of this chapter, preliminary fatigue and fracture analyses on the structure have been performed in Chapter 5 while in Chapter 6 have been summarized all the obtained conclusions and have been suggested possible improvements and close examinations which could be completed in future works. Finally two appendixes details some aspects only quoted in Chapter 3: in particular Appendix A specifies the turbulence model and the corresponding parameters used in fluid-dynamic analyses while Appendix B suggests a method alternative to the one considered for the performed analyses (through the use of MATLAB® software) to extract the load history for the coupled structural analyses

Spatial competition and efficiency : an investigation in the airport sector

This paper analyses the potential impact of airport competition on technical efficiency by applying the spatial stochastic frontier approach (SSFA) rather than traditional model (SFA). The SSFA allows to isolate the cross-sectional spatial dependence and to evaluate the role of intangible factors in influencing the airport economic performance, through the inclusion of the distance matrix and the shared destinations matrix, calibrated for different distances. By analysing statistical differences between the traditional and the spatial model, it is possible to identify the competition effects. This study includes 206 airports at worldwide level. First, the results show the existence of the spatial component, that could not be otherwise captured by the traditional SFA. Moreover, airport competition is found to affect the efficiency level with either a positive or a negative effect, depending on the distance considered in the spatial model

Pay cycles and fuel price : a quasi experimental approach

This paper studies the daily price fixing behaviour of the Spanish fuel stations. Using a difference-in-differences approach, we show that low-cost and independent operators take advantage of needier consumers. Their prices increase on the day the unemployed workers receive their subsidy from the government, whereas, on the same day, branded companies decrease their prices. Retailers, aware of this, raise the price when they know demand increases. This phenomenon emphasises the effect of pay cycles on consumer choices and their related economic impact. Findings are also relevant for Antitrust authorities which generally focus on the activities of major brands’ stations

Competition among airports at worldwide level: a spatial analysis

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Strategic behaviour by wind generators : an empirical investigation

Renewable generation of electricity is a vital step in reducing dependence on fossil fuels, and wind generation is particularly important in countries such as Britain. A large part of the windfarms are in Scotland but links with England are relatively limited and subject to exogenous failure of an interconnector. As a consequence, for a significant portion of time the system operator imposes constraints on wind generation in Scotland. We investigate the resulting effects on a majority subset of these windfarms operating under a scheme called Renewables Obligation, which involves a subsidy on top of market price. One feature of this scheme is that windfarms each declare a price at which they are willing to be constrained; these prices are used in the selection of windfarms to constrain when necessary. Thus, windfarms are sometimes paid not to produce. We investigate the strategic consequences of this, given that the prices set by windfarms to turn off in practice exceed the opportunity cost, finding significant evidence consistent with windfarm strategic behaviour. Specifically, we observe that in making their final physical declarations of output, the sample windfarms overestimate their final physical notifications of generation, the more so when other circumstances suggest constraints will be required. Following our findings we propose two potential policies to reduce both the extent of over-prediction and the payments made to windfarms to curtail output