Institution
Vattenfall
Company•Stockholm, Sweden•
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.
Topics: Wind power, Combustion, Flue gas, Power station, Offshore wind power
Papers published on a yearly basis
Papers
More filters
••
TL;DR: In this paper, the authors systematically review the state-of-the-art of biogas cleaning and upgrading technologies, including product purity and impurities, methane recovery and loss, upgrading efficiency and the investment and operating costs.
Abstract: Biogas is experiencing a period of rapid development and biogas upgrading is attracting increasing attention. Consequently, the market for biogas upgrading is facing significant challenges in terms of energy consumption and operating costs. Selection of upgrading technology is site-specific, case-sensitive and dependent on the biogas utilisation requirements and local circumstances. Therefore, matching the technology selected for use to specific requirements is significantly important. This paper systematically reviews the state-of-the-art of biogas cleaning and upgrading technologies, including product purity and impurities, methane recovery and loss, upgrading efficiency and the investment and operating costs. In addition, the potential utilisation of biogas and the corresponding requirements on gas quality are investigated in depth. Based on the results of comparisons between the technical features of upgrading technologies, the specific requirements for different gas utilizations and the relevant investment and operating costs, recommendations are made regarding appropriate technology.
610 citations
••
TL;DR: In this paper, the authors provide a comprehensive discussion of the market value of variable renewable energy (VRE) and how the inherent variability of wind speeds and solar radiation affects the price that VRE generators receive on the market (market value).
526 citations
••
TL;DR: In this article, the authors present a framework for the assessment of land use impacts in the context of the UNEP-SETAC Life Cycle Impact Assessment (LCIA) framework, which includes the reference for occupation impacts, the impact pathways to be included in the analysis, the units of measure in the impact mechanism (land use interventions to impacts), and bio-geographical differentiation.
Abstract: Background, Aim and Scope
Land use by agriculture, forestry, mining, house-building or industry leads to substantial impacts, particularly on biodiversity and on soil quality as a supplier of life support functions. Unfortunately there is no widely accepted assessment method so far for land use impacts. This paper presents an attempt, within the UNEP-SETAC Life Cycle Initiative, to provide a framework for the Life Cycle Impact Assessment (LCIA) of land use. Materials and Methods: This framework builds from previous documents, particularly the SETAC book on LCIA (Lindeijer et al. 2002), developing essential issues such as the reference for occupation impacts; the impact pathways to be included in the analysis; the units of measure in the impact mechanism (land use interventions to impacts); the ways to deal with impacts in the future; and bio-geographical differentiation. Results: The paper describes the selected impact pathways, linking the land use elementary flows (occupation; transformation) and parameters (intensity) registered in the inventory (LCI) to the midpoint impact indicators and to the relevant damage categories (natural environment and natural resources). An impact occurs when the land properties are modified (transformation) and also when the current man-made properties are maintained (occupation). Discussion: The size of impact is the difference between the effect on land quality from the studied case of land use and a suitable reference land use on the same area (dynamic reference situation). The impact depends not only on the type of land use (including coverage and intensity) but is also heavily influenced by the bio-geographical conditions of the area. The time lag between the land use intervention and the impact may be large; thus land use impacts should be calculated over a reasonable time period after the actual land use finishes, at least until a new steady state in land quality is reached. Conclusions: Guidance is provided on the definition of the dynamic reference situation and on methods and time frame to assess the impacts occurring after the actual land use. Including the occupation impacts acknowledges that humans are not the sole users of land. Recommendations and Perspectives: The main damages affected by land use that should be considered by any method to assess land use impacts in LCIA are: biodiversity (existence value); biotic production potential (including soil fertility and use value of biodiversity); ecological soil quality (including life support functions of soil other than biotic production potential). Bio-geographical differentiation is required for land use impacts, because the same intervention may have different consequences depending on the sensitivity and inherent land quality of the environment where it occurs. For the moment, an indication of how such task could be done and likely bio-geographical parameters to be considered are suggested. The recommendation of indicators for the suggested impact categories is a matter of future research.
484 citations
••
TL;DR: In this paper, the power deficit along rows of wind turbines have been determined for different inflow directions and wind speed intervals, and a method to classify the atmospheric stability based on the Bulk-Ri number has been implemented.
Abstract: The wind turbine operational characteristics, power measurements and meteorological measurements from Horns Rev offshore wind farm have been identified, synchronized, quality screened and stored in a common database as 10 min statistical data. A number of flow cases have been identified to describe the flow inside the wind farm, and the power deficits along rows of wind turbines have been determined for different inflow directions and wind speed intervals. A method to classify the atmospheric stability based on the Bulk-Ri number has been implemented. Long-term stability conditions have been established, which confirms, in line with previous results, that conditions tend towards near neutral as wind speeds increase but that both stable and unstable conditions are present at wind speeds up to 15 m s −1. Moreover, there is a strong stability directional dependence with southerly winds having fewer unstable conditions, whereas northerly winds have fewer observations in the stable classes. Stable conditions also tend to be associated with lower levels of turbulence intensity, and this relationship persists as wind speeds increase. Power deficit is a function of ambient turbulence intensity. The level of power deficit is strongly dependent on the wind turbine spacing; as turbulence intensity increases, the power deficit decreases. The power deficit is determined for four different wind turbine spacing distances and for stability classified as very stable, stable and others (near neutral to very unstable). The more stable the conditions are, the larger the power deficit. Copyright © 2011 John Wiley & Sons, Ltd.
440 citations
••
TL;DR: In this paper, the authors investigate and recommend likely maximum allowable concentrations of impurities in the CO2 for safe transportation in pipelines, including safety and toxicity limits, compression work, hydrate formation, corrosion and free water formation.
409 citations
Authors
Showing all 687 results
Name | H-index | Papers | Citations |
---|---|---|---|
Math Bollen | 59 | 519 | 17496 |
Björn Karlsson | 39 | 230 | 4638 |
Johan Westin | 29 | 78 | 5391 |
Lion Hirth | 29 | 76 | 4941 |
Anders Wörman | 28 | 109 | 3145 |
Ausilio Bauen | 28 | 52 | 3664 |
Jesper Petersson | 24 | 63 | 4359 |
Bernd Meyer | 24 | 208 | 2059 |
Frank Rosillo-Calle | 23 | 47 | 2112 |
Jan Blomgren | 22 | 147 | 1591 |
Melanie Montgomery | 18 | 66 | 926 |
Falko Ueckerdt | 18 | 40 | 2158 |
Shahriar Badiei | 17 | 20 | 626 |
Christian Bernstone | 16 | 39 | 992 |
Tomasz Kozlowski | 16 | 126 | 965 |