Evaluating the Future Efficiency of Wave Energy Converters along the NW Coast of the Iberian Peninsula (original) (raw)

Evaluation of the Wave Energy Conversion Efficiency in Various Coastal Environments

Energies, 2014

The main objective of the present work was to assess and compare the wave power resources in various offshore and nearshore areas. From this perspective, three different groups of coastal environments were considered: the western Iberian nearshore, islands and an enclosed environment with sea waves, respectively. Some of the most representative existent wave converters were evaluated in the analysis and a second objective was to compare their performances at the considered locations, and in this way to determine which is better suited for potential commercial exploitation. In order to estimate the electric power production expected in a certain location, the bivariate distributions of the occurrences corresponding to the sea states, defined by the significant wave height and the energy period, were constructed in each coastal area. The wave data were provided by hindcast studies performed with numerical wave models or based on measurements. The transformation efficiency of the wave energy into electricity is evaluated via the load factor and also through the capture width, defined as the ratio between the electric power estimated to be produced by each specific wave energy converters (WEC) and the expected wave power corresponding to the location considered. Finally, by evaluating these two different indicators, comparisons of the performances of three WEC types (Aqua Buoy, Pelamis and Wave Dragon) in the three different groups of coastal environments considered have been also carried out. The work provides valuable information related to the effectiveness of various technologies for the wave energy extraction that would operate in different coastal environments.

Wave Energy Potential Assessment and Feasibility Analysis of Wave Energy Converters. Case Study: Spanish Coast

Journal of Coastal Research, 2018

Wave energy is one of the marine renewable energy types, essential to achieve a sustainable development. Coastal countries need to know the wave energy potential along their coasts, so its contribution to the future electricity market is estimated. Spain has noticeable variations in its average wave climate, so it is essential to analyse numerous locations. For research purposes, wave energy potential is estimated based on data from the 15 Spanish State Port buoys currently in operation in deep waters. Because these buoys were set up at different times, with some moored around 2005, the sample between 2005 and 2015 is studied with the purpose of comparing results. REDEXT buoys, arranged from highest to lowest wave energy potential, are: Villano-Sisargas (56.84 kW/m), Cabo Silleiro (53.50 kW/m), Estaca de Bares (53.36 kW/m), Cabo de Peñas (39.66 kW/m), Bilbao-Vizcaya (39.09 kW/m), Gran Canaria (23.71 kW/m), Mahón (16.21 kW/m), Cabo de Begur (13.95 kW/m), Golfo de Cádiz (12.70 kW/m), Dragonera (10.16 kW/m), Cabo de Gata (8.43 kW/m), Cabo de Palos (8.17 kW/m), Tenerife Sur (6.93 kW/m), Tarragona (6.14 kW/m) and Valencia (5.42 kW/m). Some buoys were moored in the 1990s allowing an analysis to be made of how the average wave climate has changed over the last years. Furthermore, a study is undertaken analysing the feasibility of different wave energy converters, specifically Pelamis 750 kW, Oyster 300 kW, Aquabuoy 250 kW, and SSG 20,000 kW, in the 15 buoy locations. Energy production and the capacity factor of all devices for the 15 locations are calculated, obtaining as a result that the most suitable device for all the locations studied is Oyster, and the least suitable is SSG. All the results are shown in different comparative tables and figures, with a summary of the most emphasizing information in each buoy.

Assessment of the Wave Energy Conversion Patterns in Various Coastal Environments

The main objective of the present work is to assess the performances of various WEC types that would operate in the nearshore. Three different groups of coastal environments were considered. They are: the western Iberian nearshore, two archipelagos (Canaries Islands and Madeira) and the sea environment. The most representative existent wave converters are evaluated in the analysis. In order to estimate the electric power expected in a certain location, the bivariate distributions of the occurrences corresponding to the sea states, defined by the significant wave height and the energy period, were designed in each coastal area. The wave data were provided by hindcast studies performed with numerical wave models or based on measurements. The transformation efficiency of the wave energy into electricity is evaluated via the load factor and also through an index defined as the ratio between the electric power estimated to be produced by each specific WEC and the expected wave power corresponding to the location considered. The work provides valuable information related to the effectiveness of various technologies for the wave energy extraction that would operate in different coastal environments. Moreover, the results can be extrapolated to other areas.

Influence of the wave climate seasonality on the performance of a wave energy converter: A case study

Energy, 2017

CECO is a novel Wave Energy Converter (WEC) concept, which has shown promising results in previous studies. The present work focuses on assessing the performance of CECO for a 11-year horizon in relation to the characteristics of the wave climate (intra and inter-annual seasonal variations) by means of two performance indicators defined ad hoc: Captured Energy (CE) and Captured Energy Efficiency (CEE f f). For this purpose, the CECO matrix of absorbed wave power was constructed for an operating water depth of 30 m using the panel-based model ANSYS ®-AQWA TM. The Atlantic coast of the Iberian Peninsula, which presents a highly seasonal and energetic wave climate, was used as case study. Overall, it was found that CECO is able to capture large amounts of wave energy, especially for milder wave conditions, with values of CEE f f exceeding 40 %. However, for harsher wave conditions the results of CEE f f decrease considerably ranging from 10% to 20%, which may result from the current design of CECO. In this context, the results obtained offer some valuable insight into the future evolution of CECO with the purpose of addressing the limitations of the current design and to optimise its performance according to the wave conditions for specific locations.

Evaluation of Various Technologies for Wave Energy Conversion in the Portuguese Nearshore

The objective of the present work is to perform an evaluation of the performance provided by various technologies for wave energy conversion in the Portuguese continental coastal environment. The wave climate in the target area is first analyzed using the results from three years of simulations with a wave prediction system based on numerical models. Based on the above data, diagrams for the bivariate distributions of the sea states occurrences, defined by the significant wave height and the energy period, are designed for both winters and whole years. On this basis, the output of five different technologies for the conversion of wave energy is assessed in some relevant locations from the Portuguese nearshore. According to the results obtained, the Portuguese continental coastal environment appears to be appropriate for the wave energy extraction. At the same time, the present work shows that the output of the wave energy conversion devices does not depend only on the average wave energy but is also dependent on the distribution of the wave energy among the sea states of different periods. For this reason, a good agreement between the characteristics of the power matrices of the wave energy converters operating in a certain place and the diagrams for the bivariate distributions of the sea states occurrences corresponding to the considered location represents a key issue in selecting the most appropriate technology for wave energy conversion.

Assessment of Hybrid Wind-Wave Energy Resource for the NW Coast of Iberian Peninsula in a Climate Change Context

Applied Sciences, 2020

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 distanc...

Wave Energy Assessment and Performance Estimation of State of the Art Wave Energy Converters in Italian Hotspots

Sustainability

This paper presents an assessment of offshore wave energy potential at the scale of the whole Mediterranean Sea. The offshore wave data were propagated, by means of numerical modeling, toward four Italian coastal areas, namely stretches of coast of Tuscany, Liguria, Sardinia and Sicily. For each area, the wave power and the monthly, seasonal and annual variability at water depths of 50 m and 15 m were analyzed and hotspots were located. The results show strong variability of the wave energy potential from point to point of the same area thus highlighting the need for spatially detailed analysis. The higher values of wave energy potential are located in the hotspots of Sardinia and Sicily, at 11.4 kW/m and 9.1 kW/m, respectively. The Tuscany and the Liguria hotspots are characterized, respectively, by 4.7 kW/m and 2.0 kW/m. In order to point out which state of the art WEC is best suited for the Italian areas, the performances of six different state of the art Wave Energy Converters (WECs) were evaluated. Finally, a comparison of the performances of each WEC in the selected Italian sites and in some European (EU) oceanic sites was conducted. The energy potential in the most energetic EU oceanic site, among those here investigated, is up to 38-times greater than the potentials in the studied Italian areas but the power output, of the best WEC technology, is no more than nine times greater.

About the Use of 3 rd-Generation Wave Prediction Models for Estimating the Performance of Wave Energy Converters in Coastal Regions

This paper addresses the common uncertainties introduced into the long-term performance estimation of wave energy converters in coastal regions by using 3 rd -generation model wave data as input of the simulator. Indeed, the variability observed in hindcast results induces variability in the energy converted by devices, with implications on the long-term power figures. A comparison with estimates based on three different wave model data sources (produced from the WAM, Wave Watch III and SWAN wind-wave models) and buoy measurement data in the nearshore region of the French marine energy test site SEM-REV is made. The paper raises the fact that, in general, a non-negligible error is obtained -even when the wind-wave model has been appropriately designed to the local wave physics -with respect to real converted power values, which in turn results in significantly biased long-term averaged power numbers.

Planning and Development of Ocean Wave Energy Conversion

At the beginning of the 21st century, global environmental problems, including global warming, were attracting attention worldwide. In these circumstances, momentum is building across the world for the effective utilization of clean and renewable natural energy sources. The ocean is the world's largest collector and storage medium for solar energy. At the same time, it produces various forms of energy while interacting with the atmosphere. Wave energy is an indirect and condensed form of solar energy. Wave gathers their energy from the wind. Wave gather, store and transmit this energy thousands of kilometers with little loss. As long as sun shines, wave energy will never be depleted. It varies in intensity, but it is available throughout the day and year.

Efficiency assessment for different WEC types operating in the Portuguese coastal environment

IMAM 2013, 2013

The performance of various WEC types that would operate in the Portuguese continental nearshore is assessed in this work. Four devices are considered for the wave energy conversion. These are Pelamis, Archimedes Wave Swing, Aqua Buoy and Wave Dragon. Based on three years of wave model simulations, an analysis of the wave climate has been performed in the northern and the central parts of the Portuguese continental coastal environment. The transformation efficiency of the wave energy in electricity was evaluated via an index defined as the ratio between the electric power estimated to be produced by each specific WEC and the wave power corresponding to the location considered. From this perspective, the present work provides valuable information related to the effectiveness of various technologies for the wave energy extraction that would operate along the Portuguese nearshore. Moreover, the results can be easily extrapolated to some other coastal environments. based on WAM (WAve Model, WAMDI Group 1988) for wave generation and SWAN (Simulating WAves Nearshore, Booij et al. 1999) for coastal transformation was considered for various evaluations of the wave patterns in the Portuguese continental coastal environment, especially as regards the wave energy spatial distribution, as presented in Rusu & Guedes Soares (2008 and 2009), Guedes Soares et al. (2011). Considering the same approach the wave conditions and energy in the Portuguese Archipelagos Madeira and Azores, were analysed in Rusu & Guedes Soares (2012a and 2012b). Starting from the observation that various technologies for wave energy extraction can provide different efficiency in the same coastal environment, Silva et al. (2013) performed evaluations of the performances in the Portuguese continental nearshore of some different technologies for the wave energy extraction. The evaluations of the wave conditions were based this time on medium term simulations with a different wave prediction system that uses WW3 (Tolman 1991) for wave generation at the scale of the entire North Atlantic Ocean and SWAN for the coastal wave transformation. The results provided by this system were evaluated against measurements coming from two directional buoys, denoted as B1 (41.2033ºN, 9.0883ºW) and B2 (37.9211ºN, 8.9289ºW). The first one is located in the north of the Portuguese continental coast, close to the port of Leixões and operates at about 83 m water depth, and the second is located in the central part, close to the port of Sines at about 97 m.