Search results for "solar [matter]"
showing 10 items of 1254 documents
Uncertainties in polarimetric 3D reconstructions of coronal mass ejections
2015
P.P. acknowledges STFC for financial support. Date of Acceptance: 21/01/2015 Aims. The aim of this work is to quantify the uncertainties in the three-dimensional (3D) reconstruction of the location of coronal mass ejections (CMEs) obtained with the so-called polarization ratio technique. The method takes advantage of the different distributions along the line of sight of total (tB) and polarized (pB) brightnesses emitted by Thomson scattering to estimate the average location of the emitting plasma. This is particularly important to correctly identify of CME propagation angles and unprojected velocities, thus allowing better capabilities for space weather forecastings. Methods. To this end, …
Size-dependent electron transfer from atomically defined nanographenes to metal oxide nanoparticles.
2020
Atomically defined nanographenes (NGs) feature size-dependent energy gaps induced by, and tuneable through, quantum confinement. Their energy-tunability and robustness make NGs appealing candidates as active elements in sensitized geometries, where NGs functionalize a metal oxide (MO) film with large-area-to-volume ratio. Despite the prominent relevance of NG/MO interfaces for developing novel architectures for solar energy conversion, to date, little information is available regarding the fundamentals of electron transfer (ET) processes taking place from NG donors to MO acceptors. Here, we analyze the interplay between the size of atomically precise NGs and ET dynamics at NG/MO interfaces.…
Review of sustainable solar hydrogen production using photon fuel on artificial leaf
2017
Abstract Energy conversion from the renewable energy sources with suitable energy storage plays a vital role in the sustainable development. Sustainable hydrogen production from the solar energy is well suited for energy storage applications because of inherent high mass energy density of hydrogen. This manuscript reviewing the techniques required for the sustainable solar hydrogen production using photon fuel on artificial leaf, i.e. solar cell. The designing and assembling of artificial solar leaf, which is the replica of natural leaf and capable of harnessing full solar spectrum, are deliberated. This technology for sustainable solar hydrogen production will overlay a viable way for more…
Hidden energy and environmental loads of solar thermal collectors: A case study.
2001
The general aim of this work was to investigate a solar thermal collector and the energetic and environmental impacts related to this renewable technology. It was realised an eco-profile of an exemplary equipment, calculating the Cumulative Energy Demand (CED) and the Cumulative Emissions related to the production and use of a collector and the energy (or emissions) saved employing the renewable technology.
Novel Energy Efficient Schemes for Wireless Sensor Networks Utilizing Mobile Sensors
2022
Wireless sensor networks (WSNs) facilitate many applications in different fields and are well-known in both academic and industrial areas. The networks mainly include sensors, networking parts and a data processing center to collect data for a variety of purposes. However, the energy consumption problem in the networks is always a critical problem that many researchers are looking for good solutions. In this paper, we propose a data collection method that uses mobile sensors attached with bigger energy storages to collect data from static sensors. In addition, we propose a hybrid energy harvesting scheme to harvest energy from ambient environments to support static sensors to prolong the ne…
Reconfiguration strategies to reduce mismatch effects on PV array: An Arduino-based prototype
2014
Today, solar energy represents a widespread source of electricity among all the renewable energies. One of the major problems concerning the photovoltaic (PV) arrays is the partial shading, that is the non-uniform irradiance on its parts. The partial shading leads to several undesired effects, such as mismatch between modules and a reduction of the production of electric energy. In order to alleviate the partial shading effects, different methods can be employed. Among them, the reconfiguration of the electrical connections between modules represents an alternative solution. In this paper, an algorithm of reconfiguration for a small-scale PV plant is proposed and experimental results showin…
A novel renewable polygeneration system for a small Mediterranean volcanic island for the combined production of energy and water: Dynamic simulation…
2014
Abstract This paper investigates the integration of solar and geothermal energy in a novel polygeneration system producing simultaneously: electricity, thermal energy, cooling energy and fresh water. The polygeneration system under analysis includes concentrating photovoltaic/thermal solar collectors (CPVT), a Geothermal Well (GW) a multi-effect distillation (MED) system for seawater desalination, a single-stage LiBr–H2O absorption chiller and additional components, such as: storage tanks, heat exchangers and balance of plant devices. The CPVT produces simultaneously electrical energy and thermal energy, at a maximum temperature of about 100 °C. The electrical energy is delivered to the gri…
Quality Assurance and Support Measures for Solar Cooling on System Level
2016
Abstract Within the IEA SHC Task 48 “Quality assurance and support measures for Solar Cooling” the analysis and evaluation of the systems has been one of the four main focuses. Here the activities are including the lab- and field-based characterization of the systems, the definition and application of performance figures, a guideline for a reliable monitoring procedure including methods for automated error detection and an updated overview on worldwide installed DEC systems including hints and good practice examples. They are furthermore leading to three different easy-to-use tools for solar cooling systems: The LCA tool considers environmental and energetic values for the evaluation, the P…
An Overview on Solar Shading Systems for Buildings
2014
Abstract In recent years, different types of solar shading devices have been proposed, depending on building orientation, location, window characteristics, etc. They can contribute to improve or worsen building thermal and lighting performances both from an energy and comfort point of view. The present paper reports a critical analysis of some studies that investigate shading devices’ effects on building thermal and/or lighting performances. This article points out the difficulty in comparing the different results given the lack of uniformity between the studies, since they analysed buildings with different characteristics, locations and using various indices. Therefore a protocol to carry …
Sizing analysis of interior lighting using tubular daylighting devices
2017
Abstract Daylight access and indoor thermal comfort are key issues for high design level of sustainable buildings. In fact, daylight provides energy savings and visual comfort condition that can foster higher productivity and performance. This paper proposes a case study of sizing of daylight devices for zenith light. It enables the decision-making process of the designer to reach high levels of daylight factor. The proposed method is shown with an example of application. For the case study, a room in south of Italy, 24 different solar tunnels configurations and 12 cases with different number of skylights have been evaluated.