Electric Energy Efficiency in Power Production & Delivery

2020 ◽  
pp. 27-52
Author(s):  
Clark W. Gellings
Keyword(s):  
Energy Efficiency ◽  
Electric Energy ◽  
Power Production

scholarly journals The Energy Efficiency of Electric Energy as a Traction Used in Transport

2018 ◽  
Vol 14 (2) ◽  
pp. 9-14 ◽  
Author(s):  
Tomáš Skrúcaný ◽  
Saša Milojević ◽  
Štefánia Semanová ◽  
Tomáš Čechovič ◽  
Tomasz Figlus ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Environmental Impact ◽  
Electric Power ◽  
Conversion Efficiency ◽  
Electrical Power ◽  
Electric Energy ◽  
Power Production ◽  
Primary Sources ◽  
Electric Power Production ◽  
Electric Traction

Abstract The article deals with the problem of electric power production in terms of environmental impact, in particular the energy efficiency of its production to utilize primary sources. The efficiency of its production directly depends on the composition of primary sources and technologies used. Difference in efficiency by converting various forms of energy into electrical power and their ratio in the use directly affect the resulting efficiency, production of emissions and thus the environmental impact. Electric traction, its production, is burdened less efficient than other types of tractions used in transport, but at the final reconciliation of their consumption in vehicles, this difference decreases or delays because the vehicles themselves work with different conversion efficiency of its traction on mechanical work, vehicle driving.

scholarly journals Hydrodynamic constraints on the energy efficiency of droplet electricity generators

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Antoine Riaud ◽  
Cui Wang ◽  
Jia Zhou ◽  
Wanghuai Xu ◽  
Zuankai Wang
Keyword(s):  
Energy Efficiency ◽  
Kinetic Energy ◽  
Total Energy ◽  
Viscous Dissipation ◽  
Shear Force ◽  
Mechanical Energy ◽  
Electric Energy ◽  
The Past ◽  
Viscous Shear ◽  
Impingement Velocity

AbstractElectric energy generation from falling droplets has seen a hundred-fold rise in efficiency over the past few years. However, even these newest devices can only extract a small portion of the droplet energy. In this paper, we theoretically investigate the contributions of hydrodynamic and electric losses in limiting the efficiency of droplet electricity generators (DEG). We restrict our analysis to cases where the droplet contacts the electrode at maximum spread, which was observed to maximize the DEG efficiency. Herein, the electro-mechanical energy conversion occurs during the recoil that immediately follows droplet impact. We then identify three limits on existing droplet electric generators: (i) the impingement velocity is limited in order to maintain the droplet integrity; (ii) much of droplet mechanical energy is squandered in overcoming viscous shear force with the substrate; (iii) insufficient electrical charge of the substrate. Of all these effects, we found that up to 83% of the total energy available was lost by viscous dissipation during spreading. Minimizing this loss by using cascaded DEG devices to reduce the droplet kinetic energy may increase future devices efficiency beyond 10%.

Study of power transformer loading in rural power supply systems

2021 ◽  
Vol 13 (4) ◽  
pp. 282-289
Author(s):  
I. V. Naumov ◽  
D. N. Karamov ◽  
A. N. Tretyakov ◽  
M. A. Yakupova ◽  
E. S. Fedorinovа
Keyword(s):  
Energy Efficiency ◽  
Power Supply ◽  
Rural Areas ◽  
Power Transformer ◽  
Electric Energy ◽  
Power Transformers ◽  
Electric Networks ◽  
Load Factors ◽  
Optimal Load ◽  
Supply Systems

The purpose of this study is to study the effect of loading power transformers (PT) in their continuous use on their energy efficiency on a real-life example of existing rural electric networks. It is noted that the vast majority of PT in rural areas have a very low load factor, which leads to an increase in specific losses of electric energy when this is transmitted to various consumers. It is planned to optimize the existing synchronized power supply systems in rural areas by creating new power supply projects in such a way as to integrate existing power sources and ensure the most efficient loading of power transformers for the subsequent transfer of these systems to isolated ones that receive power from distributed generation facilities. As an example, we use data from an electric grid company on loading power transformers in one of the districts of the Irkutsk region. Issues related to the determination of electric energy losses in rural PT at different numerical values of their load factors are considered. A computing device was developed using modern programming tools in the MATLAB system, which has been used to calculate and plot the dependence of power losses in transformers of various capacities on the actual and recommended load factors, as well as the dependence of specific losses during the transit of 1 kVA of power through a power transformer at the actual, recommended and optimal load factors. The analysis of specific losses of electric energy at the actual, recommended and optimal load factors of PT is made. Based on the analysis, the intervals of optimal load factors for different rated power of PT of rural distribution electric networks are proposed. It is noted that to increase the energy efficiency of PT, it is necessary to reduce idling losses by increasing the load of these transformers, which can be achieved by reducing the number of transformers while changing the configuration of 0.38 kV distribution networks.

Controlling Volatility of Wind-Solar Power In Germany

2021 ◽  
Author(s):  
Hans Lustfeld
Keyword(s):  
Electric Power ◽  
Wind Turbines ◽  
Solar Power ◽  
Electric Energy ◽  
Power Production ◽  
Solar Panels ◽  
Smart Meters ◽  
Electric Energy Consumption ◽  
Process Heating ◽  
One Year

Abstract The main advantage of wind-solar power is the electric power production free of CO2. Its main disadvantage is the huge volatility of the system [national electric energy consumption powered by wind-solar power]. In fact, if this power production, averaged over one year, corresponds to the averaged electric consumption and is intended to replace all other electric power generating devices, then controlling the volatility of this system by using storage alone requires huge capacities of about 30TWh, capacities not available in Germany. However, based on German power data over the last six years (2015 till 2020) we show that the required storage capacity is decisively reduced, provided i) a surplus of wind-solar power is supplied, ii) smart meters are installed, iii) a different kind of wind turbines and solar panels is partially used, iv) a novel function describing this volatile system, is introduced. The new function, in turn, depends on three characteristic numbers, which means, that the volatility of this system is characterized by those numbers. When applying our schemes the results suggest that all the present electric energy in Germany can be obtained from controlled wind-solar power. And our results indicate that controlled wind-solar power can produce the energy for transportation, warm water, space heating and in part for process heating, requirering an increase of the electric energy production by a factor of 5. Then, however, a huge number of wind turbines and solar panels is required changing the appearance of German landscapes fundamentally.

Thermodynamic Analysis of Power Generation Cycles With High-Temperature Gas-Cooled Nuclear Reactor and Additional Coolant Heating Up to 1600 °C

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Michał Dudek ◽  
Zygmunt Kolenda ◽  
Marek Jaszczur ◽  
Wojciech Stanek
Keyword(s):  
Energy Efficiency ◽  
High Temperature ◽  
Thermodynamic Analysis ◽  
Power Plants ◽  
Nuclear Reactor ◽  
Electric Energy ◽  
High Energy ◽  
Medium Size ◽  
Outlet Temperature ◽  
High Temperature Gas

Nuclear energy is one of the possibilities ensuring energy security, environmental protection, and high energy efficiency. Among many newest solutions, special attention is paid to the medium size high-temperature gas-cooled reactors (HTGR) with wide possible applications in electric energy production and district heating systems. Actual progress can be observed in the literature and especially in new projects. The maximum outlet temperature of helium as the reactor cooling gas is about 1000 °C which results in the relatively low energy efficiency of the cycle not greater than 40–45% in comparison to 55–60% of modern conventional power plants fueled by natural gas or coal. A significant increase of energy efficiency of HTGR cycles can be achieved with the increase of helium temperature from the nuclear reactor using additional coolant heating even up to 1600 °C in heat exchanger/gas burner located before gas turbine. In this paper, new solution with additional coolant heating is presented. Thermodynamic analysis of the proposed solution with a comparison to the classical HTGR cycle will be presented showing a significant increase of energy efficiency up to about 66%.

scholarly journals Energies and Its Worldwide Research

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6700
Author(s):  
Nuria Novas ◽  
Alfredo Alcayde ◽  
Isabel Robalo ◽  
Francisco Manzano-Agugliaro ◽  
Francisco G. Montoya
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Energy Storage ◽  
Power Systems ◽  
Smart Grids ◽  
High Efficiency ◽  
Scientific Journal ◽  
Electric Energy ◽  
Electrical Energy ◽  
Energy Research

Energy efficiency and management is certainly one of the key drivers of human progress. Thus, the trends in the energy research are a topic of interest for the scientific community. The aim of this study is to highlight global research trends in this field through the analysis of a scientific journal indexed exclusively in the energy and fuels category. For this purpose, a journal has been selected that is in the center of the category considering its impact factor, which is only indexed in this category and of open access, Energies of the publisher MDPI. Therefore, a bibliometric analysis of all the contents of the journal between 2008 and 2020, 13,740 documents published, has been carried out. Analyzing the articles that are linked to each other by their citations, 14 clusters or research topics have been detected: smart grids; climate change–electric energy community; energy storage; bioenergy sources; prediction algorithms applied to power; optimization of the grid link for renewable energy; wind power; sustainability of power systems; hydrocarbon improvements; conversion of thermal/electrical energy; electric motor advancements; marine renewable energy; hydropower and energy storage; and preventive techniques in power transformers. The main keywords found were electric vehicle, renewable energy, microgrid, smart grid, and energy efficiency. In short, energy research remains necessary to meet the future challenge of sustainable energy with high efficiency and the exploration of new renewable resources, all for increasingly sustainable cities.

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