Vattenfall

About: Vattenfall is a company organization based out in Stockholm, Sweden. It is known for research contribution in the topics: Wind power & Combustion. The organization has 685 authors who have published 857 publications receiving 18912 citations. The organization is also known as: Vattenfall AB & Kungliga Vattenfallstyrelsen.

Wind direction error in the Lillgrund offshore wind farm

Abstract: The reduction of wake effects and maximisation of wind farm power output are always of interest to wind researchers [2][3]. However, one of the research challenges is to distinguish sensor errors from wake losses and losses due to poor yaw alignment. SCADA data from Lillgrund, the Swedish offshore wind farm, shows significant differences between the wind direction as measured at the met mast and as indicated by the nacelle directions measured at the individual wind turbines. Various possibilities might explain this data, the most likely being poor yaw control at particular wind turbines and/or sensor error. Both of these make power performance assessment and wake analysis problematic. In this paper, animations presented have been proved useful in the initial identification of turbines with potential problems. These anomalous turbines are then subject to a range of analyses designed to distinguish the different potential issues

Trading Volumes in Intraday Markets - Theoretical Reference Model and Empirical Observations in Selected European Markets

Abstract: This paper presents an analytical benchmark model for national intraday adjustment needs under consideration of fundamental drivers, market concentration and portfolio internal netting. The benchmark model is used to calculate the intraday market outcomes if (i) large and small players as well as transmissions operators trade and (ii) only large players and transmission system operators trade. Transaction costs may prevent the competitive fringe from intraday market participation. The theoretical national intraday trading volumes are calculated with market data from three European countries with auction-based intraday markets (Italy, Portugal, Spain) and four countries with continuous intraday markets (Denmark, France, Germany, United Kingdom). The model results allow two main conclusions: The competitive fringe is not trading on exchanges in Denmark and France but in Germany. The second conclusion is that the high observed volumes in auction-based intraday markets cannot be explained by fundamentals or the auction-based design but are mainly caused by market peculiarities. The same result applies to the UK.