scholarly journals Composing Vessel Fleets for Maintenance at Offshore Wind Farms by Solving a Dual-Level Stochastic Programming Problem Using GRASP

Logistics ◽  
2022 ◽  
Vol 6 (1) ◽  
pp. 6
Author(s):  
Kamilla Hamre Bolstad ◽  
Manu Joshi ◽  
Lars Magnus Hvattum ◽  
Magnus Stålhane
Keyword(s):  
Stochastic Programming ◽  
Optimal Solution ◽  
Wind Farms ◽  
Offshore Wind ◽  
Operational Planning ◽  
Optimal Solutions ◽  
Exact Methods ◽  
Heuristic Solution ◽  
Offshore Wind Farms ◽  
Fleet Deployment

Background: Dual-level stochastic programming is a technique that allows modelling uncertainty at two different levels, even when the time granularity differs vastly between the levels. In this paper we study the problem of determining the optimal fleet size and mix of vessels performing maintenance operations at offshore wind farms. In this problem the strategic planning spans decades, while operational planning is performed on a day-to-day basis. Since the operational planning level must somehow be taken into account when making strategic plans, and since uncertainty is present at both levels, dual-level stochastic programming is suitable. Methods: We present a heuristic solution method for the problem based on the greedy randomized adaptive search procedure (GRASP). To evaluate the operational costs of a given fleet, a novel fleet deployment heuristic (FDH) is embedded into the GRASP. Results: Computational experiments show that the FDH produces near optimal solutions to the operational day-to-day fleet deployment problem. Comparing the GRASP to exact methods, it produces near optimal solutions for small instances, while significantly improving the primal solutions for larger instances, where the exact methods do not converge. Conclusions: The proposed heuristic is suitable for solving realistic instances, and produces near optimal solution in less than 2 h.

Scheduling and Routing Optimization of Maintenance Fleet for Offshore Wind Farms Using Duo-ACO

2014 ◽  
Vol 1039 ◽  
pp. 294-301 ◽  
Author(s):  
Zhen You Zhang
Keyword(s):  
Wind Farm ◽  
Optimal Solution ◽  
Wind Farms ◽  
Daily Basis ◽  
Offshore Wind ◽  
Offshore Wind Farms ◽  
Routing Optimization ◽  
Renewable Power ◽  
Operation And Maintenance ◽  
The Cost

Wind energy is one of the fast growing sources of renewable power production currently and there is a great demand to reduce the cost of operation and maintenance to achieve competitive energy price in the market especially for offshore wind farms. An offshore wind farm usually comprises a large number of turbines and thus needs a number of service vessels for maintenance. It is already a complicated task to plan the schedule and route for each of the vessels on a daily basis, dealing with several constraints, such as weather window and maintenance demand, at the same time. Even more challenging is to find an optimal solution. This paper propose a method, i.e. Duo Ant Colony Optimization (Duo-ACO), to improve the utilization of the maintenance resources, specifically the efficient scheduling and routing of the maintenance fleet and thus reduce the operation and maintenance (O&M) cost. The proposed metaheuristic method can help operator to avoid a time-consuming process of manually planning the scheduling and routing.

scholarly journals Realistic Optimization of Parallelogram-Shaped Offshore Wind Farms Considering Continuously Distributed Wind Resources

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2895
Author(s):  
Angel G. Gonzalez-Rodriguez ◽  
Javier Serrano-González ◽  
Manuel Burgos-Payán ◽  
Jesús Manuel Riquelme-Santos
Keyword(s):  
Power Plants ◽  
Wind Farm ◽  
Continuous Distribution ◽  
Optimal Solution ◽  
Wind Farms ◽  
Offshore Wind ◽  
Optimization Approach ◽  
Offshore Wind Farm ◽  
Wind Rose ◽  
Offshore Wind Farms

Offshore wind power plants are becoming a realistic option for the renewable production of electricity. As an improvement tool to the profitability of OWFs, this work presents the first complete non-genetic (and non-binary) evolutionary algorithm to optimize the location, size and layout of a parallelogram-shaped offshore wind farm, as the arrangement that is becoming an standard for offshore wind farms. It has been tested in the HR-I site. Most relevant economic data influencing the investment profitability have been taken into account. In addition, the paper introduces a new approach to offshore wind farm optimization based on a continuous behaviour of varying wind conditions, which allows a more realistic estimation of the energy produced. The proposed optimization approach has been tested based on the available information from HR-I. Obtained solutions present similar values to the actual offshore wind farm in terms of investment and annual energy produced, but differs with respect to the optimal orientation and profitability. The contributions of this paper are: it details the first method to interpolate a continuous distribution of wind rose and Weibull parameters; it presents the first algorithm to obtain a realistic optimal solution to the location+sizing+micro-siting problem for regular arrangements; it is prepared to work with the most complete set of economic, bathymetric, and wind data.

A Practical Approach to Risk Based Assessment and Maintenance Optimisation of Offshore Wind Farms

2007 ◽  
Author(s):  
Ujjwal R. Bharadwaj ◽  
Julian B. Speck ◽  
Chris J. Ablitt
Keyword(s):  
Decision Making ◽  
Risk Analysis ◽  
Wind Farm ◽  
Net Present Value ◽  
Optimal Solution ◽  
Wind Farms ◽  
Offshore Wind ◽  
Life Extension ◽  
Offshore Wind Turbine ◽  
Offshore Wind Farms

Offshore wind farm managers are under increasing pressure to minimise life cycle costs whilst maintaining reliability or availability targets, and to operate within safety regulation. This paper presents a risk based decision-making methodology for undertaking run-repair-replace decisions with the ultimate aim of maximising the Net Present Value (NPV) of the investment in maintenance. The paper presents the methodology developed for the risk based life management of Offshore Wind farms under the remit of the CORLEX (Cost Reduction and Life Extension of Offshore Wind Farms) project funded by DTI (Department of Trade and Industry, UK) Technology Programme on Renewable Energy. Unlike traditional approaches to decision-making that consider either the probability of failure of a component or the consequence of failure in isolation, a risk-based approach considers both these aspects in combination to arrive at an optimal solution. The paper builds a basic Qualitative Risk Analysis methodology to highlight high-risk components that are then investigated further by a Quantitative Risk Analysis. The risk is now quantified in monetary terms and the time of action — replacement or maintenance — indicated by the model is such that the NPV of the action is maximized. The methodology is demonstrated by considering offshore wind turbine tower as the critical component and corrosion as the damage mechanism.

Disturbance of harbour porpoises during construction of the first seven offshore wind farms in Germany

2018 ◽  
Vol 596 ◽  
pp. 213-232 ◽  
Author(s):  
MJ Brandt ◽  
AC Dragon ◽  
A Diederichs ◽  
MA Bellmann ◽  
V Wahl ◽  
...  
Keyword(s):  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farms

Feasibility study for the installation of offshore wind farms in the Canary Islands

2009 ◽  
Vol 1 (07) ◽  
pp. 809-813
Author(s):  
M. Martínez ◽  
A. Pulido ◽  
J. Romero ◽  
N. Angulo ◽  
F. Díaz ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Canary Islands ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farms

scholarly journals Offshore wind farms and the attraction–production hypothesis: insights from a combination of stomach content and stable isotope analyses

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Ninon Mavraki ◽  
Steven Degraer ◽  
Jan Vanaverbeke
Keyword(s):  
Stable Isotope ◽  
Stomach Content ◽  
Wind Farms ◽  
Offshore Wind ◽  
Artificial Reefs ◽  
Dietary Composition ◽  
Trachurus Trachurus ◽  
Offshore Wind Farms ◽  
Scomber Scombrus ◽  
Isotope Analyses

AbstractOffshore wind farms (OWFs) act as artificial reefs, attracting high abundances of fish, which could potentially increase their local production. This study investigates the feeding ecology of fish species that abundantly occur at artificial habitats, such as OWFs, by examining the short- and the long-term dietary composition of five species: the benthopelagic Gadus morhua and Trisopterus luscus, the pelagic Scomber scombrus and Trachurus trachurus, and the benthic Myoxocephalus scorpioides. We conducted combined stomach content and stable isotope analyses to examine the short- and the time-integrated dietary composition, respectively. Our results indicated that benthopelagic and benthic species utilize artificial reefs, such as OWFs, as feeding grounds for a prolonged period, since both analyses indicated that they exploit fouling organisms occurring exclusively on artificial hard substrates. Trachurus trachurus only occasionally uses artificial reefs as oases of highly abundant resources. Scomber scombrus does not feed on fouling fauna and therefore its augmented presence in OWFs is probably related to reasons other than the enhanced food availability. The long-termed feeding preferences of benthic and benthopelagic species contribute to the hypothesis that the artificial reefs of OWFs could potentially increase the fish production in the area. However, this was not supported for the pelagic species.

scholarly journals Does galvanic cathodic protection by aluminum anodes impact marine organisms?

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Anna Maria Bell ◽  
Marcus von der Au ◽  
Julia Regnery ◽  
Matthias Schmid ◽  
Björn Meermann ◽  
...  
Keyword(s):  
Marine Environment ◽  
Cathodic Protection ◽  
Algal Growth ◽  
Wind Farms ◽  
Marine Organisms ◽  
Offshore Wind ◽  
Natural Seawater ◽  
Corophium Volutator ◽  
Offshore Wind Farms ◽  
Ecotoxicological Effects

Abstract Background Cathodic protection by sacrificial anodes composed of aluminum-zinc-indium alloys is often applied to protect offshore support structures of wind turbines from corrosion. Given the considerable growth of renewable energies and thus offshore wind farms in Germany over the last decade, increasing levels of aluminum, indium and zinc are released to the marine environment. Although these metals are ecotoxicologically well-studied, data regarding their impact on marine organisms, especially sediment-dwelling species, as well as possible ecotoxicological effects of galvanic anodes are scarce. To investigate possible ecotoxicological effects to the marine environment, the diatom Phaedactylum tricornutum, the bacterium Aliivibrio fischeri and the amphipod Corophium volutator were exposed to dissolved galvanic anodes and solutions of aluminum and zinc, respectively, in standardized laboratory tests using natural seawater. In addition to acute toxicological effects, the uptake of these elements by C. volutator was investigated. Results The investigated anode material caused no acute toxicity to the tested bacteria and only weak but significant effects on algal growth. In case of the amphipods, the single elements Al and Zn showed significant effects only at the highest tested concentrations. Moreover, an accumulation of Al and In was observed in the crustacea species. Conclusions Overall, the findings of this study indicated no direct environmental impact on the tested marine organisms by the use of galvanic anodes for cathodic protection. However, the accumulation of metals in, e.g., crustaceans might enhance their trophic transfer within the marine food web.

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