Results 1 - 10 of 1859
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[en] The increasing demand for electricity has pushed more effort to focus on renewable energy sources to satisfy the consumer. The renewable energy sources are playing a major role in the generation of electricity. Out of all the renewable energy sources, solar has emerged as one of the best sources of energy since it is clean, inexhaustible and eco-friendly. However, the voltage generated by the solar cell is not sufficient for any consumer load and it is also variable. Therefore, it is necessary to implement DCDC converters for regulating and improving the output voltage of the solar panel. In order to extract the maximum output from the PV (Photovoltaic) panel, a comparative analysis of various MPPT (Maximum Power Point Tracking) algorithms is proposed in this paper. The proposed enhanced adaptive P and O(Perturb and Observe) algorithm is modeled and implemented with a high gain DC-DC converter. The converter investigated in this paper consists of a single power electronic switch (MOSFET) for its operation, which leads to reduction of switching and conduction losses. The proposed converter has less ripple content and a high conversion ratio. A simulation study of the proposed power electronic converter powered by PV source is carried out in MATLAB/SIMULINK and the results are validated using an experimental setup. (author)
[en] Ongoing climate change affects complex and long-lived infrastructures like electricity systems. Particularly for decarbonized electricity systems based on variable renewable energies, there is a variety of impact mechanisms working differently in size and direction. Main impacts for Europe include changes in wind and solar resources, hydro power, cooling water availability for thermoelectric generation and electricity demand. Hence, it is not only important to understand the total effects, i.e., how much welfare may be gained when accounting for climate change impacts in all dimensions, but also to disentangle various effects in terms of their marginal contribution to the potential welfare loss. This paper applies a two-stage modeling framework to assess RCP8.5 climate change impacts on the European electricity system. Thereby, the performance of two electricity system design strategies - one based on no anticipation of climate change and one anticipating impacts of climate change - is studied under a variety of climate change impacts. Impacts on wind and solar resources are found to cause the largest system effects in 2100. Combined climate change impacts increase system costs of a system designed without climate change anticipation due to increased fuel and carbon permit costs. Applying a system design strategy with climate change anticipation increases the cost-optimal share of variable renewable energy based on additional wind offshore capacity in 2100, at a reduction in nuclear, wind onshore and solar PV capacity. Compared to a no anticipation strategy, total system costs are reduced.
[en] Spain is facing the challenge of transforming the energy system, with the aim of reducing 21% of greenhouse gas emissions compared to the 1990 level, achieving 42% of renewable energy on the final energy use of the country and improving in energy efficiency by 39,6%. Although the strategies in favor of renewable energies are repeated in the vast majority of countries to combat global warming, few have renounced nuclear energy since this technology is the indispensable ally to achieve a high penetration of intermittent clean energies and to fight against climate change
[es]España se enfrenta al reto de transformación del sistema energético, con el objetivo de reducir el 21 % de las emisiones de gases de efecto invernadero respecto al nivel de 1990, alcanzar un 42 % de energías renovables sobre el uso de energía final del país y mejorar en eficiencia energética un 39,6 %. Aunque las estrategias a favor de las energías renovables se repiten en la gran mayoría de los países para luchar contra el calentamiento global pocos han renunciado a la energía nuclear dado que esta tecnología es el imprescindible aliado para alcanzar una elevada penetración de energías limpias intermitentes y para luchar contra el cambio climático.
[en] While only about ten solar plants of more than 5 MW have been connected to the grid in the whole Sub-Saharan Africa, with four for Senegal, Africa remains far behind the development of solar plants, even though solar arrays and batteries are cheaper, this study aims at understanding the reasons for this failure in the development of solar energy in this continent. It first proposes an overview of the situation of solar energy in Africa (a rare and expensive electricity in most countries, a high potential but a still very low development, existing initiatives). The second part identifies and discusses the prerequisites for the development of solar projects financed by the private sector: actors present on the solar plant market in Africa, an adapted, pre-required and indispensable political and regulatory framework. The last part proposes explanations for the current delay: financing challenges, development aid policies which introduce distortions on the market, and limitations of the tendering mechanism.
[en] Energy management in home is one of the major issue now-a-days. There are different types of load like shiftable, non-shiftable, seasonal loads and auxiliary loads. In this research article, an energy management system is proposed for home which helps to schedule different loads on the basis of their types and price. It will help to minimize the cost of electricity by shifting load from peak time to off peak time. Emission will be minimized by charging penalty by adopting multi-objective optimization. Each source of energy has its own price of penalty with respect to time. Penalty is charged to minimize the use of sources like commercial supply and diesel generators which emits hazardous gases. In proposed model, user will get electricity from commercial supply, diesel generators and solar panels to provide continuous supply of electricity to fulfil the energy demand. The shiftable loads will be shifted from peak time to off peak time and higher price source to lower price source to minimize the overall price. In this research, we have proposed an EEIR (Economically Effective and Intelligently Responsive) HEMS (Home Energy Management System) by solving multi-objective optimization problem from BILP (Binary Integer Linear Programming) using branch and bound algorithm. (author)
[en] GRTgaz is a European leader in natural gas transmission, a world expert in gas transmission networks and systems, and an operator firmly committed to the energy transition. It owns and operates the gas transmission network throughout most of France, thereby helping to ensure correct operation of the French and European gas market. It contributes to the energy security of regional supply systems and performs a public service mission to ensure the continuity of consumer supply. In accordance with the French Energy Code, GRTgaz publishes a 10-year development plan for its gas distribution network in France every year. This document is produced in line with European and French energy policies. It identifies the transport infrastructure that will need to be built over the next three years, and presents the main infrastructure that is likely to be developed within the next ten years. It incorporates the supply security obligations that TSOs are required to fulfil. It takes account of interested parties' needs and projects at the national, supranational and European levels. It is based on existing gas supply and demand and reasonable medium-term development forecasts for gas infrastructure, consumption and international trade
[en] ED (Economic Dispatch) problem is one of the vital step in operational planning. It is a nonconvex constrained optimization problem. However, it is solved as convex problem by approximation of machine input/output characteristics, thus resulting in an inaccurate result. Reliable, secure and cheapest supply of electrical energy to the consumers is the prime objective in power system operational planning. Increase in fuel cost, reduction in fossil-fuel assets and ecological concerns have forced to integrate renewable energy resources in the generation mix. However, the instability of wind and solar power output affects the power network. For solution of such solar and wind integrated economic dispatch problems, evolutionary approaches are considered potential solution methodologies. These approaches are considered as potential solution methodologies for non convex ED problem. This paper presents CEED (Combined Emission Economic Dispatch) of a power system comprising of multiple solar, wind and thermal units using continuous and binary FPA (Flower Pollination Algorithm). Proposed algorithm is applied on 5, 6, 15, 26 and 40 thermal generators by integrating several solar and wind plants, for both convex and nonconvex ED problems. Proposed algorithm is simulated in MATLAB 2014b. Results of simulations, when compared with other approaches, show promise of the approach. (author)
[en] We present an overview on the evolution equations one obtains in the passage from the nonrelativistic to the relativistic framework, emphasizing the connections between the diffusive, optical and quantum models. A new evolution equation, the Pearcey equation, is introduced in the frame of this general representation. The aim of this paper is to find a relativistic counterpart of the heat equation. (author)
[en] This report proposes an overview of costs of photovoltaic installations of medium and high power (between 100 kWc and 30 MWc) developed within the frame of tenders in the French main land territory. After a presentation of methodological elements, the report addresses investment costs (general overview, connection, modules, converters, other electrical hardware, structures), exploitation costs and taxes (general overview, operation and maintenance costs, insurances, renting, electric power sale fees), financial aspects (project financing, expected profitabilities), and the global production cost (methodology, hypotheses for possible production, for costs, and for updating).