Wake losses optimization of offshore wind farms with moveable floating wind turbines

Abstract

a b s t r a c tIn the future, floating wind turbines could be used to harvest energy in deep offshore areas where higher wind mean speeds are observed. Currently, several floating turbine concepts are being designed and tested in small scale projects; in particular, one concept allows the turbine to move after installation. This article presents a novel layout optimization framework for wind farms composed of moveable floating turbines. The proposed framework uses an evolutionary optimization strategy in a nested configuration which simultaneously optimizes the anchoring locations and the wind turbine position within the mooring lines for each individual wind direction. The results show that maximum energy production is obtained when moveable wind turbines are deployed in an optimized layout. In conclusion, the framework represents a new design optimization tool for future offshore wind farms composed of moveable floating turbines.

Optimal Micro-Siting of Weathervaning Floating Wind Turbines

“…where u' is the resulting wind speed, u stands for the free-flow speed, D is the rotor diameter, C T (u 0 ) is the thrust coefficient (whose dependence on wind speed is provided by the wind turbine manufacturer), d is the downwind distance and k is the wake decay constant (a reference value of k = 0.05 is usually employed in case of offshore wind farms). It is worth noting that this wake model has also been used by the only previous work that (according to the authors' knowledge) addresses the optimization of floating wind farms [41]. Finally, the annual energy production is computed by considering the wind speed-power production characteristic of the wind turbine model, P WT (u), taking into account the actual wind speed, u', at the position of each FOWT and the occurrence probability, p(u' ij ), for a certain wind speed, as obtained by Equation 4:…”

“…However, the objective of the work is the validation of the proposed model so the work does not undertake the optimization of the problem. Rodrigues et al [41] presented a novel layout optimization framework for wind farms composed of moveable floating turbines to reduce overall losses due to wake effect. The objective was to determine the anchoring positions, as well as the positions that FOWTs can take, assuming that they can be moved in a controlled manner within a given area of movement around the anchoring location.…”

Sensitivity analysis of floating offshore wind farms

“…E: offshore wind energy produced (kW h) [44]. Finally, the cost of power (C power ) is calculated considering the total cost previously taken into account and the total power installed in MW, as Eq.…”

Wind Turbines Offshore Foundations and Connections to Grid

“…From a cost point of view, due to the investment effort required to move from currently floating "demonstration" projects to commercial ones, it is not only private investment that would be required but also and mainly government support, at least for the early phases of this transition. On the other hand, due to the technology itself of the floating structures, the installation and open costs are lower rather than for fixed structures, since most of the whole structure could be assembled directly at the dock, avoiding the huge costs coming from the installation vessels (limited due to their current availability as well as weather downtime due to bad weather conditions) [79,80].…”