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energy; solar energy, etc ; algorithms; cleaning; climate; Show all 5 Subjects
Abstract:
... Soiling of heliostat surfaces due to local climate has a direct impact on their optical efficiency and therefore a direct impact on the productivity of the Solar Power Tower plant. Cleaning techniques applied are dependent on plant construction and current schedules are normally developed considering heliostat layout patterns, providing sub-optimal results. In this paper, a method to optimise clea ...
energy conversion; renewable energy sources, etc ; spring; storms; Show all 4 Subjects
Abstract:
... To adapt to an ocean environment of changing wave period, a novel point-absorber concept is proposed: a fully-enclosed Dual Mass-Spring-Damper (DMSD) floater system that has an internal mass and spring so that its resonance frequency can be varied by changing the movable internal mass and spring. In a waterproof floater, this one-degree-of-freedom heaving energy converter can float or be submerged ...
energy; renewable energy sources, etc ; kinematics; power generation; Show all 4 Subjects
Abstract:
... The effect of an upstream bluff body on energy harvesting performance of a heaving and pitching hydrofoil is investigated numerically using a two-dimensional immersed boundary method at Re=1000. The presence of the upstream body changes flow structure around the hydrofoil and enhances efficiency significantly by two mechanisms. Mutual interaction of the vortex shed from the upstream body and the l ...
... This editorial gives a general introduction to Dynamic Energy Budget (DEB) theory, a short description of the state of the art, an introduction to the various contributions to this 6th special issue on DEB research and a short outlook. ...
primary energy; solar energy, etc ; evaporators; heat; heat pumps; tanks; Show all 6 Subjects
Abstract:
... The coupling between heat pumps and renewable energy sources is a recognized strategy to reduce primary energy consumption at the household level. This paper contributes to the present-day discussion concerning solar-assisted heat pumps for heating/cooling and to produce domestic how water. In particular, this study presents the results of a field study concerning a novel solar-assisted dual-sourc ...
energy; renewable energy sources, etc ; algorithms; foil; generators (equipment); hydrodynamics; models; Show all 7 Subjects
Abstract:
... For hydrodynamic optimization using computational fluid dynamics methods, the high computational cost impedes the use of evolutionary algorithms since they require evaluation of numerous solutions. In this paper, a multi-fidelity evolutionary algorithm, implemented with a dynamic stall model and a modified discrete vortex method, is used to find values of kinematic parameters for high energy extra ...
energy; solar energy, etc ; heat transfer; nanofluids; nanoparticles; nitrates; screening; silica; Show all 8 Subjects
Abstract:
... A high-performance heat transfer fluid (HTF) plays a crucial role in the overall performance and efficiency of the concentrating solar power (CSP) systems for utilizing solar energy. Molten salt-based nanofluids, which may offer a promising solution to help reduce the size and cost of CSP system, have attracted increasing attention. However, there is still no comprehensive assessment strategy that ...
renewable energy sources; thermal energy, etc ; microencapsulation; phase transition; polymers; Show all 5 Subjects
Abstract:
... Energy from renewable resources is a major concern nowadays and is being addressed by researchers over the globe to overcome the energy crises. Organic phase change materials are extensively utilized in thermal energy storage systems to integrate and manage the renewable energy. However, the tendency of organic phase change materials to leak out during the phase transition process, limits their pr ...
energy conversion; renewable energy sources, etc ; light intensity; solar collectors; weather; Show all 5 Subjects
Abstract:
... When performing tests on a photovoltaic energy conversion system, it is useful to have a daily-term irradiance profile which, in some way, represents the typical behavior of this variable at a desired geographic location, including fast changes caused by weather. Therefore, the objective of this work is to propose a simple methodology, to choose a representative daily-duration irradiance signal, f ...
energy; renewable energy sources, etc ; buildings; durability; heat; prototypes; vapors; Show all 7 Subjects
Abstract:
... Researchers have spent decades exploring strategies for reducing energy consumption in buildings worldwide, proposing passive solutions and optimizing active systems. However, no breakthrough technology has been developed. The use of thermoelectricity in buildings for heating, cooling and ventilation has been proposed as an alternative solution to many systems anchored in our day-to-day. This pape ...
energy; renewable energy sources, etc ; algorithms; meteorological parameters; models; power plants; Show all 6 Subjects
Abstract:
... This paper features a Multi-Objective Particle Swarm Optimization for a power plant integrated in a micro grid. The plant modeling is flexible and can be set up for a wide range of sources, storages and loads. The model contains 12 parameters representing the size of each component which are modeled with power dependent efficiencies. The optimization goals are to reduce the annualized cost of syst ...
energy; renewable energy sources, etc ; air; blades; fluid mechanics; wind turbines; Show all 6 Subjects
Abstract:
... Winglets can reduce effect of wingtip vortices on the wind turbine performance can be reduced by diffusing the vortices from the blade tips. Unlike non-rotating wings, winglets have not been widely investigated for moving blades of wind turbines, while there is a potential they could enable the wind turbine rotor to capture more kinetic energy from wind. There have been a number of studies on the ...
energy; renewable energy sources, etc ; monitoring; power plants; prototypes; Show all 5 Subjects
Abstract:
... In the present paper, the vibrational performance and its physical origins of a prototype reversible pump turbine in the pumped hydro energy storage power station is experimentally investigated. Specifically, the vibrations of the unit in the X, Y and Z directions of the top cover, the upper and the lower brackets were all measured for three water heads (from 48% to 90% in terms of non-dimensional ...
energy; energy density, etc ; activated carbon; electrochemistry; electrodes; electronic equipment; nanomaterials; Show all 7 Subjects
Abstract:
... We have developed a facile one-step hydrothermal strategy to synthesize pyramid-like NiSe₂ nanostructures, serving as electrode materials for battery–supercapacitor hybrid (BSH) devices. The NiSe₂ nanopyramid electrode exhibits superior electrochemical performances, including a high specific capacity of 240.83 mAh g⁻¹ at current density of 1 A g⁻¹ and a low internal resistance of 0.85 Ω. The all-s ...
energy; renewable energy sources, etc ; algorithms; guidelines; solar collectors; system optimization; Show all 6 Subjects
Abstract:
... In this work we propose the application of the particle swarm optimization (PSO) method to Optical-geometric optimization of linear Fresnel reflector solar concentrators (LFR). The optical-radiative behavior of the system is modeled based on the Ray tracing-Monte Carlo algorithm that calculates the optical performances and the radiative energy collected by the absorber tube. For this system, the a ...
energy; renewable energy sources, etc ; case studies; electric power; markets; politics; Show all 6 Subjects
Abstract:
... Currently, renewable energy is rapidly developing across the world in response to technical, economic and environmental developments, as well as political and social initiatives. On the other hand, excessive penetration of distributed generation (DG) systems into electrical networks may lead to various problems and operational limit violations, such as over and under voltages, excessive line losse ...
energy; energy density, etc ; graphene; graphene oxide; irradiation; quantum dots; Show all 6 Subjects
Abstract:
... Herein, we report the fabrication of nanometer-sized reduced graphene oxide (rGO) spots by swift heavy-ion (SHI) bombardment. Such structures can be considered graphene quantum dots (QDs) embedded in a non-conducting matrix. Both the number density and the diameter of the rGO spots can be tailored by a suitable choice of irradiation parameters (i.e., ion type, fluence, and energy). The degree of g ...
energy; solar energy, etc ; electricity; storage time; wind power; Texas; Show all 6 Subjects
Abstract:
... Integrating large amounts of variable generation (VG) resources such as wind and solar into a region's power grid without causing significant VG curtailment will likely require increased system flexibility via changing grid operation and deploying enabling technologies such as energy storage. This article analyzes the storage duration required to reduce VG curtailment under high-VG scenarios. The ...
energy industry; renewable energy sources, etc ; electricity; markets; monopoly; politics; China; Show all 7 Subjects
Abstract:
... The political failure of China's first independent regulator in a strategic industry – the State Electricity Regulatory Commission (SERC), 2002–2013 – provides a natural experiment to uncover fundamental challenges to a gradualist approach to electricity market formation. Taking a political institutional approach, we show that while it was largely predictable that the breakup of the monopolistic p ...
clean energy; energy; energy policy, etc ; United Nations; developing countries; development aid; electricity; environmental policy; models; renewable energy sources; sustainable development; Show all 11 Subjects
Abstract:
... Dialogues on global climate policy are increasingly discussing the sustainable energy transition, with Goal 7 of the UN’s Sustainable Development Goals highlighting the importance of affordable and clean energy. This study looks at foreign aid as a carrier of global climate policy and examines donor behaviour in the energy sector. By examining donor behaviour when giving energy aid, one can grasp ...