Search results for "ELECTRICITY"
showing 10 items of 1225 documents
Alternative Energy Policy for Mitigating the Asynchrony of the Wind-Power Industry’s Supply Chain in Brazil
2018
High dependency on hydroelectricity has revealed drawbacks in the security of power supplies as a consequence of the climate variability in South America. Under these conditions, Brazil is starting to consider alternative renewable sources for energy production, seeking to avoid periods of scarcity while also promoting clean technologies in its electricity market. Since 2004, wind power has shown a significant rise in terms of installed capacity in this country. Despite increases in wind-power units, Brazil suffers from delays in setting up its transmission infrastructure, which affects the performance of the wind-power supply chain. This chapter presents a simulation model that helps asses…
Developing an economically advantageous wind forecasting method for electricity market design with a 15-minute imbalance settlement period
2019
According to legal framework developed by European Commission all EU Member States shall employ 15minute time resolution for imbalance settlement no later than 18th of December 2020 (or 1st of January 2025 in case of derogation). For intermittent energy sources that are traditionally associated with less precise generation forecasts this might result in considerable increase in imbalance costs. This presents a unique challenge for wind power station operators as there is lack of adequate forecasting tools supporting 15-minute time-resolution. The objective of this paper is to test and provide comparative analysis of alternative data interpolation methods in order to determine approach assoc…
Hybrid Energy System for Rural Electrification in Sri Lanka: Design Study
2015
Off-grid hybrid renewable energy based power system for rural electrification has become an attractive solution for areas where grid electricity is not feasible. Depending on the availability of the resources, single energy source or a combination of several sources, including an energy storage system is used in an off-grid hybrid energy system. As there can be several candidates, the optimum sizing of the components against resource potential, cost and reliability is a vital issue. This chapter presents a study of optimum sizing of a renewable sources based off-grid hybrid energy system that is designed for electrifying a rural community in the Siyambalanduwa area in Sri Lanka. The communi…
Optimizing the generation system in a microgrid with power, thermal energy and mobility demands
2021
Microgrids are widely known to be the future of generation and distribution systems. This paper presents a method to optimize the size of the main components in a microgrid to supply the demands for electricity, heating and hydrogen for mobility through an Energy Hub model. The electricity production from a wind turbine, a CHP and a fuel cell satisfies the local electricity demand. The green hydrogen produced in the hub from renewable power in off-peak hours is used to feed the fuel cell or to meet the mobility demand. The heating power from CHP and fuel cell is used to feed the local district heating network.
Interaction of Charged Amino-Acid Side Chains with Ions: An Optimization Strategy for Classical Force Fields
2014
Many well-established classical biomolecular force fields, fitted on the solvation properties of single ions, do not necessarily describe all the details of ion pairing accurately, especially for complex polyatomic ions. Depending on the target application, it might not be sufficient to reproduce the thermodynamics of ion pairing, but it may also be necessary to correctly capture structural details, such as the coordination mode. In this work, we analyzed how classical force fields can be optimized to yield a realistic description of these different aspects of ion pairing. Given the prominent role of the interactions of negatively charged amino-acid side chains and divalent cations in many …
Heat to electricity conversion by cold carrier emissive energy harvesters
2015
This paper suggests a method to convert heat to electricity by the use of devices called cold carrier emissive energy harvesters (cold carrier EEHs). The working principle of such converters is explained and theoretical power densities and efficiencies are calculated for ideal devices. Cold carrier EEHs are based on the same device structure as hot carrier solar cells, but works in an opposite way. Whereas a hot carrier solar cell receives net radiation from the sun and converts some of this radiative heat flow into electricity, a cold carrier EEH sustains a net outflux of radiation to the surroundings while converting some of the energy supplied to it into electricity. It is shown that the…
Layer-Wise Discontinuous Galerkin Methods for Piezoelectric Laminates
2020
In this work, a novel high-order formulation for multilayered piezoelectric plates based on the combination of variable-order interior penalty discontinuous Galerkin methods and general layer-wise plate theories is presented, implemented and tested. The key feature of the formulation is the possibility to tune the order of the basis functions in both the in-plane approximation and the through-the-thickness expansion of the primary variables, namely displacements and electric potential. The results obtained from the application to the considered test cases show accuracy and robustness, thus confirming the developed technique as a supplementary computational tool for the analysis and design o…
Atomic transition probabilities for selected Yb II lines emitted from a ferroelectric plasma source
2010
The relative intensities of several hundred emission lines of Yb II between 200 nm and 900 nm were obtained with the use of ferroelectric plasma source. These relative intensities obtained for lines from 21 energy levels have been used to determine the line branching fractions, which have then been combined with accurate experimental radiative lifetime measurements to give absolute transition probabilities for 111 Yb II lines. The obtained values were compared with theoretical and experimental data taken from available literature.
New Optimization and Security Approaches to Enhance the Smart Grid Performance and Reliability
2016
International audience; Nowadays, the Smart Grid (SG) is becoming smarter thanks to the integration of different information and communication technologies to enhance the reliability and efficiency of the power grid. However, several issues should be met to ensure high SG performance. Among these issues, we cite the problem of electric vehicles (EVs) integration into the SG to avoid electricity intermittence due to the important load that EVs can create. Another issue is the SG communication network security that can be attempted by malicious intruders in order to create damages and make the power grid instable. In this context, we propose at a first level a Bayesian game-theory model that …
Generic nature of long-range repulsion mechanism on a bulk insulator?
2017
Dynamic atomic force microscopy measurements are reported that provide evidence for the presence of long-range repulsion in molecular self-assembly on a bulk insulator surface. We present the structures formed from four different benzoic acid derivatives on the (10.4) cleavage plane of calcite kept in ultra-high vacuum. These molecules have in common that they self-assemble into molecular stripes when deposited onto the surface held at room temperature. For all molecules tested, a detailed analysis of the stripe-to-stripe distance distribution reveals a clear deviation from what would be expected for randomly placed, non-interacting stripes (i.e., geometric distribution). When excluding kin…