Combining offshore wind and solar photovoltaic energy to stabilize energy supply under climate change scenarios: A case study on the western Iberian Peninsula

La expansión de la energía renovable marina es una importante alternativa para la reducción de las emisiones de gases de efecto invernadero. Sin embargo, en Europa, la alta penetración de la energía eólica marina introduce intermitencia y variabilidad de energía en la red eléctrica existente. La energía solar fotovoltaica marina es otra alternativa tecnológica en consideración en los planes de descarbonización. Sin embargo, las futuras variaciones en el viento, la temperatura del aire o la radiación solar debido al cambio climático tendrán un gran impacto en los recursos de energía renovable. En este contexto, este estudio se centra en la evaluación de la energía marina en la costa de la Península Ibérica occidental, una región europea que abarca Portugal y la parte noroccidental de España. Utilizando una amplia fuente de datos de 35 simulaciones de un proyecto de investigación llamado CORDEX, este estudio investiga la complementariedad de las fuentes de energía eólica y solar marina con el objetivo de mejorar la estabilidad del suministro de energía de esta región hasta 2040. Aunque se ha demostrado que el recurso de energía eólica marina es mayor que el recurso fotovoltaico solar a escala anual, ambos recursos renovables mostraron una variabilidad significativa en energía a lo largo de la Península Ibérica occidental. Cuando se combinan ambas fuentes renovables, la estabilidad del recurso energético aumenta considerablemente a lo largo del año. El esquema propuesto de combinación de energía eólica y solar se evalúa mediante un método de clasificación de rendimiento llamado Delphi, teniendo en cuenta la estabilidad, el recurso, el riesgo y los factores económicos. El índice de clasificación total aumenta cuando la estabilidad del recurso se mejora mediante la consideración de la producción híbrida de energía eólica-fotovoltaica solar, especialmente a lo largo de las aguas cercanas a la costa.The expansion of marine renewable power is a major alternative for the reduction of greenhouse gases emissions. In Europe, however, the high penetration of offshore wind brings intermittency and power variability into the existing power grid. Offshore solar photovoltaic power is another technological alternative under consideration in the plans for decarbonization. However, future variations in wind, air temperature or solar radiation due to climate change will have a great impact on both renewable energy resources. In this context, this study focusses on the offshore energy assessment off the coast of Western Iberia, a European region encompassing Portugal and the Northwestern part of Spain. Making use of a vast source of data from 35 simulations of a research project called CORDEX, this study investigates the complementarity of offshore wind and solar energy sources with the aim of improving the energy supply stability of this region up to 2040. Although the offshore wind energy resource has proven to be higher than solar photovoltaic resource at annual scale, both renewable resources showed significant spatiotemporal energy variability throughout the western Iberian Peninsula. When both renewable resources are combined, the stability of the energy resource increased considerably throughout the year. The proposed wind and solar combination scheme is assessed by a performance classification method called Delphi, considering stability, resource, risk, and economic factors. The total index classification increases when resource stability is improved by considering hybrid offshore wind-photovoltaic solar energy production, especially along the nearshore waters.Ministerio de Economía, Industria y Competitividad | Ref. FJCI-2017-32577Agencia Estatal de Investigación | Ref. PID2020-113245RB-I00Fundação para a Ciência e a Tecnologia | Ref. UIDB/50017/2020Fundação para a Ciência e a Tecnologia | Ref. UIDP/50017/2020Xunta de Galicia | Ref. ED431C 2021/4

Suitability of wave energy converters in northwestern Spain under the near future winter wave climate

Marine renewable energies can play a key role by reducing the dependency on fossil fuels and, therefore, mitigating climate change. Among them, it is expected that wave energy will experience rapid growth in the upcoming decades. Thus, it is important to know how wave climate will change and how suitable the wave energy converters (WECs) will be to the new wave conditions. This paper aims to evaluate the capability of four different WECs—a WaveRoller type device (WRTD), Atargis, AquaBuoy and RM5—to extract wave energy on the Northwest coast of Spain (NWCS). The analysis was performed using the high-resolution wave data obtained from the Simulating Waves Nearshore (SWAN) model over the near future winters (2026–2045). The energy output (PE), the power load factor (ε), the normalized capture width (NCw) and the operational time (OT) were analyzed. According to these parameters, among the devices that work for intermediate-deep waters, Atargis would be the best option (PE=1400 ± 56 kW, ε =55.4 ± 2.2%, NCw=35.5 ± 4.1% and OT =84.5 ± 3.3%). The WRTD would also be a good option for shallow nearshore areas with PE=427 ± 248 kW, ε =12.8 ± 7.4%, NCw = 48.9 ± 9.6% and OT = 88.7 ± 18.9%. A combination of Atargis and WRTDs is proposed to make up the future wave energy farms on the NWCS.Xunta de Galicia | Ref. ED431C 2021/44Ministerio de Ciencia e Innovación | Ref. PID2020-113245RB-I00Agencia Estatal de Investigación | Ref. TED2021-129479A-100Ministerio de Ciencia e Innovación | Ref. IJC2020-043745-IAgencia Estatal de Investigación | Ref. PRE2021-097580Universidade de Vigo/CISU

Different approaches to analyze the impact of future climate change on the exploitation of wave energy

The increment of the share of renewable energies in the global mix implies that all renewable energies must be exploited. In this sense, it is necessary to make significant research and investment effort in the particular case of wave energy to reach the degree of maturity of other marine energies in the near future. Apart from the inherent factors that hinder the development of wave energy, such as the non-existence of a market-leading type of capturing device, uncertainties about the available future resource also hamper its growth. In this article, a review of the procedures followed in the literature to deal with the future wave energy resources and their subsequent exploitation is described. These procedures include the evaluation of the best future atmospheric models to drive wave models, the different downscaling techniques to evaluate the resource in large regions with high spatial resolution, and the analysis of the variability of the future energy resource and its future exploitability in a certain region taking into account different types of devices. Additionally, the current state of the art of previous studies dealing with future wave energy resources for different locations worldwide is described. Despite the difficulties involved in studying future wave energy resources, the high technological readiness level of the offshore wind industry, the creation of power generation farms with combined technologies, and the growth of marine aquaculture in the coming years could generate synergies that provide the definitive impulse to achieve the necessary technological development.Agencia Estatal de Investigación | Ref. PID2020‐113245RB‐I00Agencia Estatal de Investigación | Ref. TED2021-129479A-I00Xunta de Galicia | Ref. ED431C 2021/44Agencia Estatal de Investigación | Ref. IJC2020-043745-IAgencia Estatal de Investigación | Ref. PRE2021-097580European Cooperation in Science and TechnologyUniversidade de Vigo/CISU