• Energy Research

The progressive energy transition to systems with higher shares of renewable energy is particularly important in islands regions, which are largely dependent on energy imports. In this context, to assess the impact of climate change on renewable energy resources during the 21st century is crucial for polycimakers and stakeholders. In this work, we provide an overview of wind and photovoltaic (PV) resources, its variability and complementarity between them, as well as their future changes, in the Canary Islands and surrounding areas. Variability is assessed through the analysis of energy droughts (low-productivity periods). In addition, a sensitivity test is performed to find the optimal combination of PV (photovoltaic) and wind that reduce energy droughts and the persistence of that conditions at a local scale. A set of climate simulations from the MENA-CORDEX runs are used, in present and future climate (2046–2065, 2081–2100) for two different scenarios (RCP2.6, RCP8.5). Results show different changes in wind productivity depending on the scenario: a decrease in RCP2.6 and an increase in the RCP8.5. PV experienced a subtle decrease, with some exceptions. Changes in variability are small and the complementarity test shows that high shares of PV energy (above 50%) reduce both, energy droughts and the persistence of drought conditions.

Abstract Electricity demand for cooling and heating is directly related to weather and climate, primarily through ambient temperature. In Southern Europe, the maximum electricity demand for cooling in summer can be more pronounced than in winter, especially during heat wave (HW) episodes. With the growth of renewable technologies in the energy mix, the dependency of the electricity system on the weather is becoming evident not just from the demand side, but also from the energy supply side. From the resources point of view, summer wind presents a minimum on its annual cycle, so a combination of maximum electricity demand can coincide with a minimum of wind power production. This study presents a strong multidisciplinary focus, merging climate, energy and environmental discipline, due to their relevant connections in Southern Europe where important climate change stresses are expected. The combined anomalies of electricity demand and wind production during heat wave episodes are quantified at the country level, taking into account the HW extension. The summer period (1989-2019) of ERA5 reanalysis and E-OBS-21.0e data is used for atmospheric magnitudes and the Copernicus climate change service (C3S) energy dataset for demand. In heat wave events, an increase of 3.5%–10.6% in electricity demand and a decrease up to −30.8% in wind power production is obtained, with variability depending on the country. The greater the extension of the HW, the greater the anomalies. Different weather regimes related to heatwaves also play a role on this range of values. Therefore, the impact of extreme weather events, such as heatwaves, on wind power production in conditions of high electricity demand, should be considered in the energy supply strategy and planning in order to minimize the impact of these events on an electricity system with high penetration of renewables.

The Mediterranean Sea is a climate change hotspot since it provides a magnified warming signal. Heavily populated areas (e.g., Spanish Mediterranean coasts) are vulnerable to negative socio-economic impacts. This is particularly important for climate-related economic sectors such as coastal tourism, the focus of this paper. To promote a sustainable development of these activities and provide key information to stakeholders, it is necessary to anticipate changes in climate. Thus, it is fundamental to use climate modelling tools which account for air-sea interactions, which largely determine the climate signal of the Mediterranean coasts. In this paper, a set of regional air-sea coupled climate model simulations from Med-CORDEX are used to (i) study the climatic conditions on the Spanish Mediterranean coasts in the next decade(s) and (ii) to assess the possibility of extending the coastal tourist season towards spring-fall. We show that climate conditions are getting warmer and drier in the area, especially in summer. Heat waves and heavy precipitation will become more frequent. Thermal discomfort will increase in summer and summer conditions are extending towards spring and fall. Our work remarks the urgent need of adaptation measures of the sector, including the extension of the high tourist season to spring-fall, especially in the long term. We make a special effort to compile a set of adaptation measures for stakeholders. This study is part of the project ECOAZUL-MED, which aims to create a climate service tool to optimize the management of relevant sectors of the blue economy in the Spanish Mediterranean coasts. This publication is part of the project ECOAZUL-MED (PTQ2020-011287), funded by MCIN/AEI/10.13039/501100011033, and by “European Union NextGenerationEU/PRTR”. C. Gutiérrez and W. Cabos were supported by the National Ministry of Science “Proyectos de Generación de Conocimiento 2021” grant number PID2021-128656OB-I00. The Mediterranean Centre for Environmental Studies (CEAM) is partly supported by Generalitat Valenciana. The contribution of Samira Khodayar Pardo was supported by the program Generació Talent of Generalitat Valenciana (CIDEGENT/2018/017).

Renewable energy resources are variable by nature. Due to this fact conventional electricity systems, which were designed for centralized generation, have to follow a different management approach when a big share of these technologies take part into the system. The space-time variability characteristics of solar radiation, wind and precipitation are very different and a detailed understanding of them is important for an adequate planning and management of the electricity system.

AbstractCierzo in the Ebro Valley and Levante and Poniente in the Strait of Gibraltar are three of the main winds over the Iberian Peninsula. However, their study is difficult due to the limited amount of observational data and available literature. In addition, current reanalysis products do not usually have sufficient resolution, generally greater than 10 km, to capture the orographic characteristics of these winds. In this study we explore the ability of high‐resolution COSMO‐REA6 reanalysis (6 km, 0.055°) to describe Cierzo, Levante and Poniente using HadISD observational data validation whenever it was possible. A numerical definition according to the characteristics of these winds is proposed through speed and directional range thresholds. Regional winds statistics, annual cycles, wind roses and covered areas are calculated. The results show a reasonable agreement between reanalysis and observations, with an annual average of 95 Cierzo days, and around 80 Levante and Poniente days for the whole period. These windy days typically extend around 21,000 km2 (or 600 reanalysis cells). Both extension and number of days present strong annual cycles and interannual variability. Several weather regimes associated to those regional wind days are obtained, in agreement with other comparable studies. Therefore, the study shows the capability of the high‐resolution COSMO‐REA6 reanalysis to capture and describe regional winds such as Cierzo, Levante and Poniente.

The enhanced vulnerability of insular regions to climate change has been recently recognized by the European Union, which highlights the importance of undertaking adaptation and mitigation strategies according to the specific singularities of the islands. In general, islands are highly dependent on energy imports which, in turn, feature a marked seasonal demand. Efforts to reduce greenhouse gas emissions in these regions can therefore fulfill a twofold objective: (i) to increase the renewable energy share for global decarbonization and (ii) to reduce the external energy dependence for isolated (or interconnected) systems in which this can only be achieved with an increase of the renewable energy share. However, the increase in renewable technologies makes energy generation more dependent on future climate and its variability. The main aim of this study is to analyze future projections of wind and photovoltaic potential, as well as energy productivity droughts, on the main Euro-Mediterranean islands. Due to the limitations in land surface available in the islands for the installation of renewable energy capacity, the analysis is extended to offshore wind and photovoltaic energy, which may have an important role in the future increases of renewable energy share. To that end, we use climate variables from a series of simulations derived from Euro-CORDEX (Coordinated Downscaling Experiment) simulations for the RCP2.6 and RCP8.5 emission scenarios. A special effort is performed to normalize projected changes and the associated uncertainties. The obtained normalized changes make it easier the intercomparison between the results obtained in the different islands and constitute condensed and valuable information that aims to facilitate climate-related policy decision making for decarbonization and Blue Growth in the islands.

Abstract The advances in floating offshore wind energy are opening deep sea areas, like the coastal waters of Iberian Peninsula (IP), for the installation of wind farms. The integration of this new energy source in a semi-closed power system with an already high share of variable renewable energies would be facilitated if the potential contribution of offshore wind energy shows reduced variability and limited seasonal variations, as the power demand in IP shows two maxima in winter and summer. The aims of this study are the analysis of temporal variability and spatial complementarity of the potential installation sites, and the identification of an optimal combination of installation areas that minimizes the temporal variability of the aggregated offshore contribution. In order to better capture the marked mesoscale features of winds around the IP, wind data from a very high resolution reanalysis (COSMO-REA6) are used. The analysis considers allowed areas for installation, delimited by the maritime spatial planning. Northern coast areas are characterized by high capacity factors (CFs) and high seasonality, while the lower CFs at the western and southern coasts are compensated by a limited seasonality. Pairwise correlation between the potential areas shows outstanding results, with several negative correlation values within a synoptic scale region, in contrast to other mid-latitude regions like the North Sea or the Eastern USA coast. An optimal aggregation of areas includes at least one area at each of the four main Iberian coasts. A strong reduction of hourly variability is obtained through the resulting combinations, and the seasonality of the aggregated CF is clearly below the values for other offshore areas. Therefore, offshore wind energy can indeed offer an added value for the Iberian power system beyond the high resource amount, reducing the need for storage or backup plants.