Economic Feasibility of Floating Offshore Wind Farms Considering Near Future Wind Resources: Case Study of Iberian Coast and Bay of Biscay

[Abstract] Wind energy resources are subject to changes in climate, so the use of wind energy density projections in the near future is essential to determine the viability and profitability of wind farms at particular locations. Thus, a step forward in determining the economic assessment of floating offshore wind farms was taken by considering current and near-future wind energy resources in assessing the main parameters that determine the economic viability (net present value, internal rate of return, and levelized cost of energy) of wind farms. This study was carried out along the Atlantic coast from Brest to Cape St. Vincent. Results show that the future reduction in wind energy density (2%–6%) mainly affects the net present value (NPV) of the farm and has little influence on the levelized cost of energy (LCOE). This study provides a good estimate of the economic viability of OWFs (Offshore Wind Farms) by taking into account how wind resources can vary due to climate change over the lifetime of the farm.Ministerio de Ciencia e Innovación; 10.13039/501100011033.Xunta de Galicia; ED431C 2017/6

Aprovechamiento de la energía undimotriz a lo largo de la costa gallega

Ponencia presentada en: XII Congreso de la Asociación Española de Climatología celebrado en Santiago de Compostela entre el 19 y el 21 de octubre de 2022.[ES]Se ha calculado el recurso undimotriz a lo largo de la costa gallega (noroeste de España) durante el periodo 2014-2021 usando datos horarios de alta resolución espacial procedentes del modelo Simulating WAves Nearshore (SWAN). Además, se analizó la potencia eléctrica (PE) y el rendimiento que puede obtenerse del conversor de energía undimotriz (WEC) Wave Dragon. El rendimiento del Wave Dragon se calculó atendiendo a dos parámetros: el factor de carga de potencia (ε) y el ancho de captura normalizado respecto a la geometría del WEC (eficiencia). Los resultados muestran que el recurso undimotriz es menor que 10 kWm-1 cerca de la costa, pero aumenta hasta 55 kWm-1 en mar abierto. Wave Dragon presenta valores de PE menores a 500 kW en el interior de las rías y ~2200 kW en mar abierto. Además, alcanza valores de 25−30% en la costa noroeste y la eficiencia alcanza hasta el 40% en la costa oeste. Debido a su profundidad óptima de operación y a los resultados obtenidos, Wave Dragon parece ser una buena opción para aprovechar la energía undimotriz en la costa gallega.[EN]The wave power resource (WP) has been calculated along the Galician coast (NW Spain) over the period 2014-2021 using high spatial resolution hourly data from the Simulating Waves Nearshore (SWAN) model. In addition, the electrical power energy (PE) that can be extracted for the Wave Dragon wave energy converter (WEC) was analyzed. The performance of Wave Dragon has also been calculated attending to two parameters: the power load factor (ε) and the normalized capture width with respect to the WEC’s geometry (efficiency). Results show that the WP resource is lower than 10 kWm-1 onshore but it increases to about 55 kWm-1 offshore. Wave Dragon presents PE values less than 500 kW inside the estuaries and ~2200 kW offshore. Additionally, ε reaches values of 25−30% on the Northwest Coast and the efficiency reaches up to 40% on the West Coast. Due to its optimum operating depth and the results obtained, Wave Dragon seems to be a good option to implement wave energy on the Galician coast

Development of Offshore Wind Power: Contrasting Optimal Wind Sites with Legal Restrictions in Galicia, Spain

The region of Galicia, in the northwest of the Iberian Peninsula, has a high wind potential for the installation of offshore wind farms (OWFs) in many areas of its surrounding marine waters. However, legal restrictions derived from the protection of other interests that converge in the marine environment (such as fishing, navigation, and biodiversity conservation) must be considered, along with technical limitations resulting from water depth. This study is aimed at analysing legal restrictions on the installation of OWFs in Galician waters and at identifying those zones of less conflict where the wind power density (WPD) is greater and the depths and distances from the coast are technically feasible given the current status of technology in Europe. To do this, a legal study was performed of both the strategic environmental assessment of the Spanish coast and the regulations of the different marine sectors at European, international, national, and regional levels. In addition, the WPD along the north-western area of the Iberian Peninsula and Europe was calculated, and an analysis of maximum and average depths and distances from the coast of planned and installed OWFs in Europe was made. Two main zones without legal and technical restrictions were identified in the north-eastern corner of Galicia and in the south of the Vigo estuary. The greatest WPD was identified in the north-western zone, from Cape Finisterre to Cape Ortegal, where there are small sites without legal or technical restrictions that are near several protected zones (such as a marine reserve, a special protected area, and a wetland and its buffer zone), making necessary a deeper analysis of the specific impacts of each OWF project in the Environmental Impact Assessment

Assessment of hybrid wind-wave energy resource for the NW coast of Iberian Peninsula in a climate change context

Offshore renewable energy has a high potential for ensuring the successful implementation of the European decarbonization agenda planned for the near future. Hybrid wind-wave farms can reduce installation and maintenance costs, and increase the renewable energy availability of a location by compensating for the wind’s intermittent nature with good wave conditions. In addition, wave farms can provide protection to wind farms, and the combined wind/wave farm can provide coastal protection. This work aims to assess the future hybrid wind-wave energy resource for the northwest coast of Iberian Peninsula for the near future (2026–2045), under the RCP 8.5 greenhouse gas emission scenario. This assessment was accomplished by applying a Delphi classification method to define four categories, aiming to evaluate the richness (wind and wave energy availability, downtime), the variability (temporal variation), the environmental risk (extreme events), and cost parameters (water depth and distance to coast) of the wind and wave resources. The combined index (CI), which classifies the hybrid wind-wave resource, shows that most of the NW Iberian Peninsula presents good conditions (CI > 0.6) for exploiting energy from wind and wave resources simultaneously. Additionally, there are some particularly optimal areas (CI > 0.7), such as the region near Cape Roca, and the Galician coast.Fundación Portuguesa de Ciencias (FCT) | Ref. (SFRH / BD / 114919/2016)FCT / MCTES | Ref. (UIDB / 50017/2020 + UIDP / 50017/2020)Xunta de Galicia | Ref. proyecto ED431C 2017/64-GRCMinisterio de Economía y Competitividad | Ref. proyecto “WELCOME ENE2016-75074-C2-1-R"FCT/MCTES | Ref. UIDP/50017/2020Ministério da Ciência, Tecnologia e Ensino SuperiorEuropean CommissionEuropean Regional Development FundEuropean Cooperation in Science and Technolog

Correlations between annual maxima and winter anomalies of PLD/TLD calculated from ARGO and SODA databases for the period 2003–2010.

<p>Threshold values of ΔT = 0.5°C and Δσ_θ = 0.125 kg/m³ were used for potential temperature and for potential density, respectively. Statistical significance (p value) is showed in brackets.</p

Comparison between Argo and SODA databases.

<p>(a) Isopycnal layer depth and (b) isothermal layer depth variability using Argo database (blue line) and SODA database (red line). A 1-2-1 filter was used to smooth signals only for visualization.</p

Trends of atmospheric variables.

<p>(a) Air temperature trend (°C dec⁻¹), (b) P-E (precipitation minus evaporation) balance trend (mm dec⁻¹) and (c) wind stress trend (N m⁻²dec⁻¹) calculated for the whole Bay of Biscay over the period 1975–2010. Black dots represent points with a significance level higher than 90%.</p

Trend values of mixed layer depth.

<p>(a) (b) Annual maxima trends and (c) (d) winter anomalies trends (m dec⁻¹) of PLD (left) and TLD (right) in the Bay of Biscay for the period 1975–2010. Black dots represent points with a significance level higher than 90%.</p

Bay of Biscay bathymetry (m).

<p>The isobath corresponds to -1000 m.</p

Left, correlations between points of negative air temperature trends (T_air⁻) and points of positive annual maxima (PLD_m/TLD_m) and winter anomalies (PLD_a/TLD_a) trends.

<p>Right, correlations between points of positive air temperature trends (T_air⁺) and points of negative annual maxima (PLD_m/TLD_m) and winter anomalies (PLD_a/TLD_a) trends. Statistical significance (p value) is showed in brackets.</p