Co-located wave-wind farms: Economic assessment as a function of layout

Energy Conversion and Management

2016

Self Cite

The shadow effect a b s t r a c t Combined energy systems present an opportunity to enhance the competitiveness of renewables and overcome other challenges of these novel renewables by realising the synergies between them. Among the different possibilities for combined systems, this work focuses on wave and wind co-located farms with the aim of assessing their benefits relative to standalone wind farms. To this end we estimate the energy production, investigate the power smoothing and shadow effect, and quantify the reduction in downtime achieved by the co-located farm through a case study off the Danish coast -a promising area for co-located farms based on the available resource and other considerations including technical constraints. The analysis is carried out based on hindcast data and observations extending from 2005 to 2015, and by means of state-of-the-art numerical models of the wind and wave fields -WAsP and SWAN, respectively. It is found that the energy yield per unit area with the combined wave-wind farm increases by 3.4% relative to a standalone wind farm, the downtime periods decrease by 58% and the power output variability reduces by 12.5%. Moreover, the capital and operational expenditures (CAPEX and OPEX, respectively) would also be significantly reduced thanks to the synergies realised through the combination of wind and wave power.

“…Taking this into consideration, reductions of approx. 10% of the O&M cost can be achieved [80], which would correspond to savings of 4 M€/year for the co-located farm here analysed.…”

Section: Co-located Farm Resultsmentioning

confidence: 80%

Section: Co-located Farm Resultsmentioning

confidence: 99%

Section: Co-located Wave and Wind Farm Layoutmentioning

confidence: 99%

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Selecting optimum locations for co-located wave and wind energy farms. Part II: A case study

Astariz

Energy Conversion and Management

2016

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“…(c) Cable costs are mainly estimated on the basis of the exporting cable cost, which is the cable that allows delivering the electricity produced to a land-based electrical substation [38,39]. They are highly sensitive to the cable length, which is directly related to the distance to shoreline (L).…”

Section: Tidal Stream Energy: Economic Potentialmentioning

confidence: 99%

A holistic method for selecting tidal stream energy hotspots under technical, economic and functional constraints

Vazquez

Energy Conversion and Management

2016

Self Cite

Although a number of prospective locations for tidal stream farms have been identified, the development of a unified approach for selecting the optimum site in a region remains a current research topic. The objective of this work is to develop and apply a methodology for determining the most suitable sites for tidal stream farms, i.e. sites whose characteristics maximise power performance, minimise cost and avoid conflicts with competing uses of the marine space. Illustrated through a case study in the Bristol Channel, the method uses a validated hydrodynamics model to identify highly energetic areas and a geospatial Matlab-based program (designed ad hoc) to estimate the energy output that a tidal farm at the site with a given technology would have. This output is then used to obtain the spatial distribution of the levelised cost of energy and, on this basis, to preselect certain areas. Subsequently, potential conflicts with other functions of the marine space (e.g. fishing, shipping) are considered. The result is a selection of areas for tidal stream energy development based on a holistic approach, encompassing the relevant technical, economic and functional aspects. This methodology can lead to a significant improvement in the selection of tidal sites, thereby increasing the possibilities of project acceptance and development.

“…Moreover, the cost of O & M tasks can be reduced in co-located farms since the scheduled maintenance of wave and wind energy can be organised to be done at the same time or in continuous length of time [53]. A recent study [94] achieved cost savings around 25% in the capital costs and up to 14% in the maintenance costs of combined wave and wind energy farms. Moreover, offshore developers pay for leases according to the area occupied, so covering the same area with two sources of electricity generation reduces these costs.…”

Section: Co-located Wind and Wave Energy Farmsmentioning

confidence: 99%

Enhancing Wave Energy Competitiveness through Co-Located Wind and Wave Energy Farms. A Review on the Shadow Effect

Astariz

2015

Energies

Abstract:Wave energy is one of the most promising alternatives to fossil fuels due to the enormous available resource; however, its development may be slowed as it is often regarded as uneconomical. The largest cost reductions are expected to be obtained through economies of scale and technological progress. In this sense, the incorporation of wave energy systems into offshore wind energy farms is an opportunity to foster the development of wave energy. The synergies between both renewables can be realised through these co-located energy farms and, thus, some challenges of offshore wind energy can be met. Among them, this paper focuses on the longer non-operational periods of offshore wind turbines-relative to their onshore counterparts-typically caused by delays in maintenance due to the harsh marine conditions. Co-located wave energy converters would act as a barrier extracting energy from the waves and resulting in a shielding effect over the wind farm. On this basis, the aim of this paper is to analyse wave energy economics in a holistic way, as well as the synergies between wave and offshore wind energy, focusing on the shadow effect and the associated increase in the accessibility to the wind turbines.