Energy production and distribution Quantification and modelling of epistemic uncertainties for availability risk of future offshore wind farms using expert judgment

Abstract Levelized cost of energy (LCoE) is the most common metric used in renewable energy assessments. However, this can be a very complex calculation with numerous methodologies depending on the perspective taken. Inputs including costs, energy production are generally forecasts and predictions based on publicly available information; therefore, they are key areas of uncertainty. Elements of the calculation are site or region specific such as the tax rate or inclusion of grid connection costs. The business case and financial assumptions applied will be very project specific, e.g., the discount rate applied. These numerous variables and uncertainties must be fully understood in order to effectively apply the metric or review and compare LCoEs. Therefore, this paper provides a comprehensive set of LCoE methodologies that provide a reference basis for researchers. A case study demonstrates the application of these methods and the variation in results illustrates the importance of correctly selecting the discount rate and cash flow based on the perspective and motivation of the user. Sensitivity studies further investigates the potential impact of key variables and areas of uncertainty on results. Analysis indicates that the energy production and discount rate applied will have the most significant impact on LCoE, followed by Capital Expenditure (CAPEX) costs. While the key areas of uncertainties cannot necessarily be solved, this paper promotes consistency in the application and understanding of the metric, which can help overcome its limitations.

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A Minimalistic Prediction Model to Determine Energy Production and Costs of Offshore Wind Farms

Energies ◽

10.3390/en14020448 ◽

2021 ◽

Vol 14 (2) ◽

pp. 448

Author(s):

Jens Nørkær Sørensen ◽

Gunner Christian Larsen

Keyword(s):

Prediction Model ◽

Wind Turbines ◽

Water Depth ◽

Energy Production ◽

Wind Farm ◽

Cost Model ◽

Wind Farms ◽

Offshore Wind ◽

Offshore Wind Farms ◽

The Cost

A numerical framework for determining the available wind power and associated costs related to the development of large-scale offshore wind farms is presented. The idea is to develop a fast and robust minimal prediction model, which with a limited number of easy accessible input variables can determine the annual energy output and associated costs for a specified offshore wind farm. The utilized approach combines an energy production model for offshore-located wind farms with an associated cost model that only demands global input parameters, such as wind turbine rotor diameter, nameplate capacity, area of the wind farm, number of turbines, water depth, and mean wind speed Weibull parameters for the site. The cost model includes expressions for the most essential wind farm cost elements—such as costs of wind turbines, support structures, cables and electrical substations, as well as costs of operation and maintenance—as function of rotor size, interspatial distance between the wind turbines, and water depth. The numbers used in the cost model are based on previous but updatable experiences from offshore wind farms, and are therefore, in general, moderately conservative. The model is validated against data from existing wind farms, and shows generally a very good agreement with actual performance and cost results for a series of well-documented wind farms.

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Use of Markov Decision Processes in the Evaluation of Corrective Maintenance Scheduling Policies for Offshore Wind Farms

Energies ◽

10.3390/en12152993 ◽

2019 ◽

Vol 12 (15) ◽

pp. 2993 ◽

Cited By ~ 1

Author(s):

Helene Seyr ◽

Michael Muskulus

Keyword(s):

Energy Production ◽

Wind Farms ◽

Offshore Wind ◽

Offshore Wind Farms ◽

Corrective Maintenance ◽

Current State ◽

Markov Decision ◽

Maintenance Policies ◽

Cost Efficient

Optimization of the maintenance policies for offshore wind parks is an important step in lowering the costs of energy production from wind. The yield from wind energy production is expected to fall, which will increase the need to be cost efficient. In this article, the Markov decision process is presented and how it can be applied to evaluate different policies for corrective maintenance planning. In the case study, we show an alternative to the current state-of-the-art policy for corrective maintenance that will achieve a cost-reduction when energy production prices drop below the current levels. The presented method can be extended and applied to evaluate additional policies, with some examples provided.

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Perspectives on offshore wind farms development in chosen countries of European Union

Journal of Water and Land Development ◽

10.2478/jwld-2018-0039 ◽

2018 ◽

Vol 38 (1) ◽

pp. 27-34

Author(s):

Leszek Dawid

Keyword(s):

European Union ◽

Wind Energy ◽

Energy Production ◽

Wind Farm ◽

Wind Farms ◽

Offshore Wind ◽

Offshore Wind Energy ◽

The European Union ◽

Offshore Wind Farms ◽

Under Construction

AbstractAt the end of 2016 there were 84 wind farms under construction in 11 European countries. Investments in this sector are enormous. The average cost of a wind farm construction amounts to approx. 4 mln EUR per 1 MW of installed power. Offshore wind energy production also plays a significant role in the process of ensuring energy security in Europe, and in reduction of greenhouse gases. The objective of this paper is to present prospects of offshore wind energy farms development in the leading member states of the European Union as regards this problem. In this paper offshore wind farms in Germany and Denmark have been studied. In the paper the power of wind farms, the support systems as well as criteria related to location of wind farm offshore have been analysed. German and Danish sectors of offshore wind energy are strongly supported by respective governments. Both countries aim at yearly increase of wind energy share in total energy production. The research has been conducted based on the analysis of acts, regulations, the subject’s literature and information from websites.

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Velocity Deficit and Swirl in the Turbulent Wake of a Wind Turbine

Marine Technology Society Journal ◽

10.4031/mtsj.47.4.20 ◽

2013 ◽

Vol 47 (4) ◽

pp. 193-205 ◽

Cited By ~ 19

Author(s):

Nathaniel P. Dufresne ◽

Martin Wosnik

Keyword(s):

Velocity Field ◽

Wind Turbine ◽

Energy Production ◽

Similarity Theory ◽

Wind Farms ◽

Field Measurements ◽

Azimuthal Velocity ◽

Offshore Wind ◽

Offshore Wind Farms ◽

Blade Tip

AbstractEnergy production data from several of the existing large offshore wind farms indicate that turbine arrays can suffer from a significant overall energy production shortfall, due to wakes generated by turbines upstream interacting with turbines downstream. An experimental investigation of the axial and azimuthal (swirl) velocity field in the wake of a single three-bladed wind turbine with rotor diameter of 0.91 m was conducted. The turbine was positioned in the free stream, near the entrance of the 6 m×2.7 m cross section of the UNH Flow Physics Facility, a 72-m-long boundary layer wind tunnel. The turbine model was tested at various rotor loading conditions with blade tip-speed ratios up to 2.8. A Pitot-static tube and constant temperature hot-wire anemometry with a multiwire sensor were used to obtain velocity field measurements in the wake of the model turbine up to 20 diameters downstream. The results of an equilibrium similarity theory for the axisymmetric wake with rotation are presented. The measurements obtained were used to examine the validity of the derived scaling functions for streamwise and azimuthal velocity, wake growth, and turbulence.

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