During the past few decades, wave energy has received significant attention for harnessing ocean energy. Industry has proposed many technologies and, based on their working principle, these ...technologies generally can be categorized into oscillating water columns, point absorbers, overtopping systems, and bottom-hinged systems. In particular, many researchers have focused on modeling the point absorber, which is thought to be the most cost-efficient technology to extract wave energy. To model such devices, several modeling methods have been used such as analytical methods, boundary integral equation methods and Navier–Stokes equation methods. The first two are generally combined with the use of empirical solution to represent the viscous damping effect, while the last one is directly included in the solution. To assist the development of wave energy conversion (WEC) technologies, this paper extensively reviews the methods for modeling point absorbers.
Energy depletion is one of the significant threats to global development. To increase the usability of clean energy, the energy storage performance of dielectric materials must be urgently enhanced. ...Semicrystalline ferroelectric polymer (PVDF) is the most promising candidate for the next generation of flexible dielectric materials thanks to its relatively high energy storage density. In this work, high-entropy spinel ferrite (Lasub.0.14Cesub.0.14Mnsub.0.14Zrsub.0.14Cusub.0.14Casub.0.14Nisub.0.14Fesub.2Osub.4) nanofibers (abbreviated 7FO NFs) were prepared by the sol-gel and electrostatic spinning methods, then blended with PVDF to prepare composite films using the coating method. A magnetic field was used to control the orientation distribution of the high-entropy spinel nanofibers in the PVDF matrix. We investigated the effects of the applied magnetic field and the content of high-entropy spinel ferrite on the structure, dielectric, and energy storage properties of the PVDF substrate films. The 3 vol% 7FO/PVDF film treated in a 0.8 T magnetic field for 3 min exhibited a good overall performance. The maximum discharge energy density was 6.23 J/cmsup.3 at 275 kV/mm and the efficiency was 58% with 51% β-phase content. In addition, the dielectric constant and dielectric loss were 13.3 and 0.035, respectively, at a frequency of 1 kHz.
The Indus, Ganges and Brahmaputra river basins support 700 million people in Asia. The water resources are used for irrigation, drinking, industry, navigation and hydropower. This paper reviews the ...literature on the impact of climate change on the hydrological regime of these river basins and suggests that the different basins are likely to be affected in different ways. Climate change will have a marked affect on meltwater in the Indus Basin and may result in increased flood risk in the Brahmaputra Basin. The overall impact on annual discharge is likely to be low, but more studies are required to understand intra-annual changes and the impact of extreme events.
Water-power scenarios to 2033: A mixed model Hafezi, Reza; Wood, David A.; Alipour, Mohammad ...
Environmental science & policy,
October 2023, 2023-10-00, Letnik:
148
Journal Article
Recenzirano
The balancing of energy and water supply-demand involves a challenging issue. Policymakers at both global and national levels are striving to ensure the security of energy and water supply while ...supporting economic growth. This study investigates the nexus between water and power and explores potential future directions at global and national perspectives. It considers the case of Iran, as a resource-rich developing economy, to assess real-world influences and potential outcomes. The research proposes an enhanced layered uncertainties scenario synthesizing model to develop and evaluate plausible futures within a 10-year planning horizon (2033). The model employs a novel data-gathering procedure based on experts’ inputs and intuitionistic fuzzy averaging to facilitate reliable judgments in a highly uncertain environment. Findings reveal that, from the global perspective, an energy transition is likely to gain momentum during the next decade, but the water intensity (quantity of water supplied per unit of GDP) is expected to gradually decrease. Providing reliable and secured electricity and water supply, especially for the less developed economies is likely to become an increasingly challenging matter, hindering their potential financial and technological development. The period to 2033 in Iran is expected to be shaped by political issues and international sanctions, making them the most significant future drivers. These factors are likely to have a substantial impact on Iran's decisions regarding energy and water development, as they may affect foreign investment, the cost of money, and water competition diplomacy.
•Stochastic scenario model based on expert judgments in an uncertain environment.•Water-power nexus (WPN) global and national futures are developed and interpreted.•Models reveal that WPN behaves chaotically, particularly at national levels.•WPN becomes more predictable and difficult to change at regional and global levels.•The layered uncertainties scenario synthesizing model provides useful WPN insight.
Sardinia (Italy) is the second largest island in the Mediterranean Sea and its economy is penalized by high costs of electricity, which is double compared to the continental Italian regions, and ...triple compared to the EU average. In this research, the wave energy potential of the north-west of Sardinia has been studied by an analysis of wave measurements carried out in a 20-year period by the Italian Wave Buoys Network (1989–2009) and the corresponding hindcast data by the European Centre for Medium-Range Weather Forecasts (ECMWF). The annual offshore wave power was found to range between 8.91 kW/m and 10.29 kW/m, the bulk of which is provided by north-westerly waves. The nearshore energetic patterns have been studied by means of a numerical coastal propagation model (Mike21 NSW). The analyses highlight two “hot spots” where the wave power is respectively 9.95 and 10.91 kW/m. For these locations, a Wave Energy Converter with maximum efficiency in the ranges of significant wave heights between 3.5 and 4.5 m (energy periods 9.5–11 s) and 4–6 m (energy periods 9.5–11.5 s) respectively should be selected. In order to find a concrete solution to the problem of harvesting wave energy in this area, the characterization of waves providing energy is considered along with additional considerations, such as installation and operational costs, institutional factors, environmental sensitivity and interferences with others human activities. On the basis of the information available and the identified circumstances, the site of Bosa Marina has been proposed as a prospective wave farm location. For this site in particular, multifunctional structures like harbour or coastal protection breakwaters equipped with a WEC are recommended.
► Wave energy potential of the North-West of Sardinia (Italy) has been studied. ► Twenty years of wave buoy records and hindcast data were used. ► The annual offshore wave power ranges between 8.91 kW/m and 10.29 kW/m. ► The nearshore energetic patterns have been studied by means of a numerical model. ► Two “hot spots” were found with wave power of 9.95 and 10.91 kW/m respectively.
The Mediterranean basin is considered one of the most vulnerable regions of the world to climate change and such changes impact the capacity of ecosystems to provide goods and services to human ...society. The predicted future scenarios for this region present an increased frequency of floods and extended droughts, especially at the Iberian Peninsula. This paper evaluates the impacts of climate change on the water provisioning and erosion control services in the densely populated Mediterranean Llobregat river basin of. The assessment of ecosystem services and their mapping at the basin scale identify the current pressures on the river basin including the source area in the Pyrenees Mountains. Drinking water provisioning is expected to decrease between 3 and 49%, while total hydropower production will decrease between 5 and 43%. Erosion control will be reduced by up to 23%, indicating that costs for dredging the reservoirs as well as for treating drinking water will also increase. Based on these data, the concept for an appropriate quantification and related spatial visualization of ecosystem service is elaborated and discussed.
•Mediterranean hydrological ecosystem services (HES) are threatened by climate change.•Provisioning (water) services are expected to decrease between 3 and 49%.•Regulating (erosion control) services are expected to decrease between 5 and 43%.•Pyrenees mountains are a significant contributor in Llobregat basin's water yield.•The mean sediment retention is decreasing from upper to lower part of the basin.
A review on green energy potentials in Iran Hosseini, Seyed Ehsan; Andwari, Amin Mahmoudzadeh; Wahid, Mazlan Abdul ...
Renewable & sustainable energy reviews,
11/2013, Letnik:
27
Journal Article
Recenzirano
Iran is one of the main non-renewable energy producers in the world due to its plentiful fossil fuel resources. Utilization of natural gas and petroleum in transportation and industrial sectors has ...been developed vastly in Iran because of their low prices. Consequently, the increasing rate of pollutant formation and depletion of non-renewable fuels have emerged as new challenges in the energy scenario of this country. Since Iran has plenty of fossil fuel resources, alternative fuel and renewable resources have not been taken into consideration seriously. This existing trend of fossil fuel utilization is not according to the sustainable development aims which have been adapted for the country. Recently, controlling the unbridled fossil fuel consumption has become one of the main targets of the Iranian Government. A variety of natural resources in different regions of Iran can be applied as the main sources of renewable and sustainable energy (RSE) and considered as the supplementary energy in the energy mix policies. Biofuel, hydropower, wind, solar and geothermal are the main RSE that can be utilized for energy supply. Moreover, regarding the increasing rate of the population, bioenergy generation from waste materials can play a crucial role in sustainability of waste management strategies. In this regard, the present study has been conducted to evaluate renewable energy potentials from various resources in Iran.
Acoustic telemetry represents the state-of-the-art technology for monitoring behaviour of aquatic organisms in the wild. Yet, the performance of different systems is rarely evaluated across species ...and environments. In this study, we evaluate two different acoustic telemetry systems, a commonly used analogue pulse-position-modulation-based system (VEMCO PPM) and a newly developed high-residency digital binary phase shift key-based system (VEMCO HR2), in ability to track downstream migrating Atlantic salmon smolt (Salmo salar) and European eel (Anguilla anguilla) around hydropower facilities. High-precision GPS were used to evaluate precision and accuracy of hyperbolically positioned data derived from each system. The PPM-based system had higher detection range than HR2 and generated more positions per transmission for eels migrating close to bottom than for surface-oriented salmon smolts. HR2 generated tenfold more positions per time unit than PPM, were less sensitive to noise, achieved submetre positional precision, and were considerably more accurate than PPM-derived positions after filtering. HR2 was deemed more capable than PPM in fine-scale positioning at moderate distances at hydropower facilities.
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