• Energy Research
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• 14. Life underwater close
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Uncertainty surrounding the potential environmental impacts of marine energy (ME) has resulted in extensive and expensive environmental monitoring requirements for ME deployments. Recently, there have been more ME deployments and associated environmental data collection efforts, but no standardized methodologies for data collection. This hinders the use of previously collected data to inform new ME project permitting efforts. Triton Field Trials (TFiT), created at the Pacific Northwest National Laboratory by the United States (U.S.) Department of Energy, explores ways to promote more consistent environmental data collection and enable data transferability across ME device types and locations. Documents from 118 previous ME projects or ME-related research studies in the U.S. and internationally were reviewed to identify the highest priority stressor–receptor relationships to be investigated and the technologies and methodologies used to address them. Thirteen potential field sites were assessed to determine suitable locations for testing the performance of relevant monitoring technologies. This introductory paper provides an overview of how priority research areas and associated promising technologies were identified as well as how testing locations were identified for TFiT activities. Through these scoping efforts, TFiT focused on four activity areas: collision risk, underwater noise, electromagnetic fields, and changes in habitat. Technologies and methodologies were tested at field sites in Alaska, Washington, California, and New Hampshire. Detailed information on the effectiveness of the identified methodologies and specific recommendations for each of the four focus areas are included in the companion papers in this Special Issue.

The objective of this paper is to present an integrated picture of the relationship between the waves and the modifications induced by them in the Romanian shoreline. Thus, the hydrodynamic processes at the Mangalia beaches, located in the southern side of the Romanian nearshore, are simulated using the modeling system Mike 21 SW (MIKE 21 Spectral Waves), developed by the Danish Hydration Institute (DHI). This is one of the newest spectral wave models, which can be used for regional- and local-scale simulations. The model has been calibrated and validated using buoy measurements. The analysis of the statistical parameters shows a good match between the model and the observed data. Furthermore, a model to compare the differences that occur on the beach profiles between the cold and warm seasons was developed. The results obtained indicate a reinforcement of the coastal erosion in the winter, when the waves are stronger (especially in January and February).

This article presents the creation of bathymetric cartography for San Andrés, Providencia, Santa Catalina, and the Colombian Caribbean to find suitable areas for implementing an ocean thermal energy conversion (OTEC) system. The methodology to obtain the bathymetry uses data collection, digitization, and interpolation. The data are processed using the Surfer® software; in this way, the digital terrain model (DTM) maps are generated for each sector. The objective is to find the minimum distance to reach a depth of 1000 m since this is the distance where a temperature difference of 20 ∘C is obtained. Thus, it is possible to identify suitable areas to locate an onshore or offshore plant in Santa Marta, Barranquilla, southwestern and northwestern San Andrés, the western part of Santa Catalina, and the southwestern part of Providencia.

Accurate evaluations of the available and technically exploitable wave energy resources are fundamental to optimise the design and implementation of energy converters in the marine environment. However, long-term resource assessments have been primarily conducted for large-scale devices in offshore energetic locations, thus ignoring onshore sites such as harbours with easier access, installation and accessibility to devices. Here, we conducted a ten-year evaluation of the performance of wave energy converters (WECs) off Roscoff harbour (northern Brittany, France). As the site of application shows moderately energetic conditions, particular attention was dedicated to small-scale WECs by adapting ratings to the local wave climate. This investigation combined (i) a high-spatial resolution (~5 m) hindcast database established with SWAN with (ii) generic and specific assessments of WEC performance. We exploited, in particular, scaled power matrices derived from the Oyster technology to assess the capacity factors and energy output of devices. In addition to characterising the annual and seasonal variability of the available resource off the harbour breakwater, this investigation provided further insights for optimising WECs, including experimental prototypes. It is therefore suggested that this type of evaluation be considered for the assessment of small- and/or full-scale energy converters in the marine environment.

Over recent decades, the exploitation of wave energy resources has sparked a wide range of technologies dedicated to capturing the available power with maximum efficiency, reduced costs, and minimum environmental impacts. These different objectives are fundamental to guarantee the development of the marine wave energy sector, but require also refined assessments of available resource and expected generated power to optimize devices designs and locations. We reviewed here the most recent resource characterizations starting from (i) investigations based on available observations (in situ and satellite) and hindcast databases to (ii) refined numerical simulations specifically dedicated to wave power assessments. After an overall description of formulations and energy metrics adopted in resource characterization, we exhibited the benefits, limitations and potential of the different methods discussing results obtained in the most energetic locations around the world. Particular attention was dedicated to uncertainties in the assessment of the available and expected powers associated with wave–climate temporal variability, physical processes (such as wave–current interactions), model implementation and energy extraction. This up-to-date review provided original methods complementing the standard technical specifications liable to feed advanced wave energy resource assessment.

Current advances in wave energy technologies have enabled the development of new integrated measurement platforms powered by the energy of wave motion. Instrumentation is now being deployed for the long-term observation of the coastal ocean, with the objectives of analyzing the performance of wave energy converters (WECs) and studying their interactions with the surrounding environment and marine life. In this work, we present the most relevant findings of the installation and initial operation of the Open Sea Lab (OSL), the first coastal observatory in Latin America powered entirely by a WEC device. We evaluated the preliminary data regarding the combined operation of the system, the generation of energy, and the observations obtained by the continuous monitoring of physical variables at the site. The data showed the seasonal variability of the energy produced by the WEC for a range of wave heights during the period of observation. We also investigated the rapid development of biofouling on mooring lines, junction boxes, and other parts of the system, which is characteristic of the settlement and growth of organisms in this ocean region. These analyses show how this new facility will advance our understanding of the coastal environment in the south Pacific Ocean and foster new interdisciplinary collaborations addressing environmental and technical challenges, thereby contributing to the development of wave energy on the continent.

The article presents general principles of development of the lower Vistula channel in the Holocene period, with a particular emphasis on the unintentional human interference in the fluvial processes associated with deforestation and cultivation of cereals and root crops. It also characterises the basic hydraulic engineering works in the form of construction of embankments, adjustment of the bed and construction of the Włocławek barrage as factors of deliberate human interference and their impact on channel changes. The article characterises morphological and morphodynamic conditions of the basic bed forms, i.e. sandy and gravel bars and pools determining the possibility of river transport, and its development in time and space (depth of navigable route). Perspectives of multi-directional hydraulic development are presented, including the main cascade developments of the lower Vistula. The article presents the opportunities for a comprehensive use of the waterway, which forms route E40 in the section of the lower Vistula, taking into account sustainable development and compensation in the form of restoration of the valley bottom.

One of the most encouraging sorts of renewable energy is ocean wave energy. In spite of a large number of investigations in this field during the last decade, wave energy technologies are recognised as neither mature nor broadly commercialised compared to other renewable energy technologies. In this paper, we develop and optimise Power Take-off (PTO) configurations of a well-known wave energy converter (WEC) called a point absorber. This WEC is a fully submerged buoy with three tethers, which was proposed and developed by Carnegie Clean Energy Company in Australia. Optimising the WEC’s PTO parameters is a challenging engineering problem due to the high dimensionality and complexity of the search space. This research compares the performance of five state-of-the-art metaheuristics (including Covariance Matrix Adaptation Evolution Strategy, Gray Wolf optimiser, Harris Hawks optimisation, and Grasshopper Optimisation Algorithm) based on the real wave scenario in Sydney sea state. The experimental achievements show that the Multiverse optimisation (MVO) algorithm performs better than the other metaheuristics applied in this work.