• Energy Research

Chinese offshore wind energy sector is experiencing a rapid growth. It is expected that China will become the world leader in terms of installed offshore wind energy capacity in the upcoming years. A multi-model ensemble of eight simulations from CORDEX project was considered to evaluate future offshore wind energy projections along the Chinese coast under the RCP8.5 warming scenario. Furthermore, offshore wind energy resource was classified attending to the richness of the resource, stability of the resource, risk and economic factors. The reliability of the CORDEX multi-model ensemble was analyzed by comparing CORDEX wind speed with two different datasets: in-situ data from oceanic buoys and ERA5 database. A general wind power density decrease was observed for the near future and the far future. At seasonal scale, differences were found depending on the season. Thus, a clear reduction was projected during spring, whilst increases were observed in wide areas during winter or autumn. Regarding the classification of the future offshore wind energy resource for the upcoming decades, most of the Chinese coastal area was defined as good or excellent due to its high offshore wind energy richness that compensate the low values on stability of the resource and risk factor. Agencia Estatal de Investigación | Ref. FJCI-2017-32577 Xunta de Galicia | Ref. ED431C 2017/64 Fundação para a Ciência e a Tecnologia | Ref. CEECIND/01726/2017 Fundação para a Ciência e a Tecnologia | Ref. UIDP/50017/2020 Fundação para a Ciência e a Tecnologia | Ref. UIDB/50017/2020

The Atacama desert is a region with exceptional conditions for solar power production. However, despite its relevance, the impact of climate change on this resource in this region has barely been studied. Here, we use regional climate models to explore how climate change will affect the photovoltaic solar power resource per square meter ( ) in Atacama. Models project average reductions in of 1.5% and 1.7% under an RCP8.5 scenario, respectively, for 2021-2040 and 2041-2060. Under RCP2.6 and the same periods, reductions range between 1.2% and 0.5%. Also, we study the contribution to future changes in of the downwelling shortwave radiation, air temperature and wind velocity. We find that the contribution from changes in wind velocity is negligible. Future changes of downwelling shortwave radiation, under the RCP8.5 scenario, cause up to 87% of the decrease of for 2021-2040 and 84% for 2041-2060. Rising temperatures due to climate change are responsible for drops in ranging between 13%–19% under RCP2.6 and 14%–16% under RCP8.5. Xunta de Galicia | Ref. ED431C 2021/44 Universidad de Vigo/CISUG Ministerio de Ciencia e Innovación | Ref. IJC2020-043745-I Ministerio de Universidades

The efficiency of wave energy converters (WECs) is generally evaluated in terms of historical wave conditions that do not necessarily represent the conditions that those devices will encounter when put into operation. The main objective of the study is to assess the historical and near future efficiency and energy cost of two WECs (Aqua Buoy and Pelamis). A SWAN model was used to downscale the wave parameters along the NW coast of the Iberian Peninsula both for a historical period (1979–2005) and the near future (2026–2045) under the RCP 8.5 greenhouse scenario. The past and future efficiency of both WECs were computed in terms of two parameters that capture the relationship between sea states and the WEC power matrices: the load factor and the capture width. The wave power resource and the electric power capacity of both the WECs will decrease in the near future. The load factor for Aqua Buoy will decrease in the entire area, while it will remain unchanged for Pelamis in most of the area, except north of 43.5° N. The capture width and cost of energy will increase for both devices. The methodology here applied can be easily applied to any device and coastal domain under different climate change scenarios.

Abstract The accuracy of CORDEX regional models to reproduce wind speed was assessed at 15 wind farms (216 wind turbines) and 13 oceanic buoys covering the Iberian Peninsula and surrounding ocean during 2012. Models were able to reproduce with relative accuracy both the mean wind speed, with a mean error of 19% inland and 10% offshore, and the wind distribution, with an overlap percentage between distributions of 82 ± 5% inland and 83 ± 3% offshore. In addition, CORDEX regional models showed a skill higher than CMIP5 general models. Wind speed and wind power were projected over the Iberian Peninsula (Spain and Portugal) and the surrounding ocean for three future periods: near future (2019–2045), midterm (2046–2072) and far future (2073–2099) both at annual and seasonal scales. Both wind speed and wind power will decrease over most of the area with the exception of some regions as: Galicia; the Atlantic coast of Galicia and north of Portugal; the Ebro Valley; the upper Douro Valley; the Guadalquivir Valley; the Strait of Gibraltar and Cape Gata where both will tend to increase. This increase is projected to occur mostly during summer except at the Strait of Gibraltar where it will occur all year long. The change in wind speed and power is higher as farthest the future period is.

Abstract The performance of the WRF mesoscale model in the wind simulation and wind energy estimates was assessed and evaluated under different initial and boundary forcing conditions. Due to the continuous evolution and progress in the development of reanalyses datasets, this work aims to compare an older, yet widely used, reanalysis (the NCEP-R2) with three recently released reanalyses datasets that represent the new generation of this type of data (ERA-Interim, NASA-MERRA and NCEP-CFSR). Due to its intensive use in wind energy assessment studies, the NCEP-GFS and NCEP-FNL analysis were also used to drive WRF and its results compared to those of the simulations driven by reanalyses. Six different WRF simulations were conducted and their results compared to measured wind data collected at thirteen wind measuring stations located in Portugal in areas of high wind energy potential. Based on the analysis and results presented in this work, it can be concluded that the new generation reanalyses are able to provide a considerable improvement in wind simulation when compared to the older reanalyses. Among all the initial and boundary conditions datasets tested here, ERA-Interim reanalysis is the one that likely provides the most realistic initial and boundary data, providing the best estimates of the local wind regimes and potential wind energy production. The NCEP-GFS and NCEP-FNL analyses seem to be the best alternatives to ERA-Interim, showing better results than all the other reanalyses datasets here tested, and can therefore be considered as valid alternatives to ERA-Interim, in particular for cases where reliable forcing data is needed for real-time applications due to its fast availability.

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.

Abstract Climate change impact on future European large-scale wind energy resource under the latest IPCC CMIP5 future climate projections were analysed. After assessing the models that best reproduce contemporary near-surface wind speeds over Europe, their data was used to assess future changes in the wind energetic resource in Europe. Using a multi-model ensemble composed by the models that showed the best ability to represent contemporary near-surface wind speeds over Europe, the future European large-scale wind energetic resource is projected to increase in Northern-Central Europe (Baltic Sea and surrounding areas), and decrease in the Mediterranean region, mainly by the end of the current century and under stronger radiative forcing scenarios. It is also projected an increase of the intra-annual variability in the Baltic Sea and surrounding areas and a decrease in Mediterranean areas, but no significant changes in the inter-annual variability are expected over Europe. Despite the large uncertainty associated to future climate projections, the findings of this work can serve as background for future downscaling of CMIP5 data to regional-local scales focused on climate change impacts on wind energy, and should be seen as a preliminary warning that a continuous increase of greenhouse gases emissions are expected to impact European wind energy production.