Search

The integration of electricity grids with technologies for small-scale distributed generation based on natural gas consumption is one of the most important innovative directions for improving the reliability and energy efficiency of power systems. Synchronous operation of large energy consumers and distributed generation systems is a new element of the electricity system. This element is an industrial microgrid, which has a unique ability to control the operating modes of the electrical energy system compared to conventional industrial electricity consumers. The aim of this study is to develop a theory and methodology for the use of microgrids in industrial areas under the market-based conditions of electricity and natural gas purchase. An analysis of trends in the use of small-scale distributed generation shows that the operation of distributed generation based on renewable energy sources is not economically feasible in all countries. In some countries, such as Russia, for example, the use of distributed energy sources powered by natural gas is the most important. The study of pricing principles for the purchase of energy in the wholesale and retail electricity markets and for the purchase of natural gas from regional suppliers and on commodity exchanges shows that managing the volatility of energy demand schedules can have a significant impact on the prices of electricity and natural gas used by industrial companies and large consumers of energy resources. As part of a unified power system, industrial enterprises and small distributed generation systems simultaneously consume electricity from the Unified Energy System, generate electricity through a distributed generation system into the internal network of the enterprise and external network the power system, and consume natural gas through the enterprise consumption system and the distributed generation system. Synchronised operation of an industrial enterprise and a small system of distributed generation system in the unified control system of a microgrid enables the enterprise to reduce the combined costs of purchasing energy resources and increase the efficiency and reliability of power supply to equipment. The article presents a system of factors influencing the demand of microgrids for electricity and natural gas consumption and develops a model for the integrated control of industrial microgrids under their integration with the technology for managing the demand of industrial enterprises for electricity and natural gas consumption. The control algorithm developed for a microgrid takes into account the cross effects of changes in its energy and gas demand, energy market price factors, internal constraints for industrial load management, external external of the Unified Energy System and the Unified Gas Supply System, and the ability to meet the energy demand of external consumers of the microgrid. The paper is of scientific and practical importance and can be used in the process of developing, implementing and managing microgrids at industrial enterprises in Russia and around the world.

Continuity of power supply service in production industries is of crucial importance, given the severity imposed in these sectors. A poor power supply leads to underproduction or degradation of equipment sensitive to electrical variations. A direct consequence of this is loss of earnings for industry. To ensure continuity of service for industrial power supplies, at least one secondary power source must be available. However, the switching system between sources may not be spontaneous due to the presence of electromechanical switches. The solution to this problem is to use electronic converters for control. The aim of this work is to enhance the parameters of an industrial photovoltaic-grid hybrid power supply to ensure uninterrupted power supply and balance between energy supply and demand. The sources are coupled to the DC bus via electronic converters. The photovoltaic system and the inverter are assumed to be unknown, and only the load terminal voltage is accessible and measurable. To address the lack of mathematical model of the system, we propose a mechanism that combines a fuzzy logic (FLC) centred mechanism with a radial basis function (RBF) neural network for the studied case. The FLC self-determines the image of the compensation power to be extracted through the current to the secondary energy source, ensuring continuity of service and balance between supply and demand. The FLC mechanism self-adjust the parameters of the RBF neural network and coordinates the energy at the DC link. The results obtained in the Matlab/Simulink environment are compared with the fuzzy logic and proportional integral (PI) control method. The quality of the results show that the proposed method is excellent compared with FLC and PI control. It improves response time between 24.223% and 82.9% for PI and between 22.292% and 63.694% for FLC. It guarantees an improvement in the mean square error on PI of between 5.865% and 57.994%, and on FLC of between 1.582% and 29.683%. The proposed method guarantees a high rationing coefficient, helping to maintain the balance between supply and demand, ensure continuity of service for the power supply, and improve the accuracy and self-compensation of the energy to be supplied, both qualitatively and quantitatively.

Building on the historical foundations of the geopolitics of energy, this essay argues that under capitalism, the "energy model" performs more functions than only supplying energy to the system. In the fossil fuel model, the territorial control of energy sources (coal, oil, gas, and uranium) preserves hegemony, and since the 1970s, oil revenue has been used to sustain global imbalances. Considering that the properties of renewable sources are radically different from those of fossil fuels (there is no possibility of territorial control or commodification), I discuss the concepts of soft and hard paths as established by Lovins and using the example of "new hydrogen geopolitics," in an attempt to create a hard path renewable model similar to the fossil fuel one, may foster new tensions that could catalyze a new generation of energy-related conflicts. [ABSTRACT FROM AUTHOR]

Highlights • Energy exchanges between interconnected utilities has been performed. • Electric energy production is estimated from different fuel sources. • Oligopolistic energy market models with uncertainty/certainty have been proposed. • The power-flow study verifies the quantitative nature of the energy exchange. Abstract An analysis of estimating the electric energy production from different fuel sources and its exchanges between interconnected utilities has been performed, based on the historical trend of economic growth. We used a model that considers meeting the load by committed generators where capacity weighted availability has been factored in for generating units run by same types of fuel. The focus is on Bangladesh, in particular, studying energy exchanges between its different regions as well as potential international energy trading between selected countries in South East Asia (SEA). Another aspect of the paper is to study the utilization of energy resources with less possible negative environmental impacts. Our model also accommodates the effect of gradual/impulsive changes of energy generation and availability of different energy sources. The estimated values match well with the actual energy generation, as reported in Bangladesh power authority's publication. Based on the evaluated expected energy generation, oligopolistic energy market models with uncertainty/certainty have been proposed here to show the probable trading in private sector, and in the mix of private and public sector utilities. Market models also consider the potential cross-border trading. In addition, a power-flow study has been conducted to verify the quantitative nature of energy exchanges between regions. This analysis is intended to facilitate energy system planners and designers with the necessary tools to predict energy distribution in growing electric power systems. [ABSTRACT FROM AUTHOR]

Abstract The identification of abnormal power consumption state is an important but difficult issue in power consumption. The State Grid Corporation of China's electric energy data acquisition system is only capable of acquiring power consumption big data collected by smart energy meter terminals. In view of this fact, this study presents a method for identifying abnormal power consumption state. First, the spectral distribution of eigenvalues of the covariance matrix of the high-dimensional random matrix of massive volumes of power consumption data is analyzed based on high-dimensional random matrix theory. Then, a power consumption big data-based abnormal power consumption state identification method is proposed based on the statistical properties of random matrices. Finally, simulations are performed based on actual power consumption data from Guizhou Province, China. The simulation results show that the proposed method can not only satisfy urgent requirements of power grids for visualization, timeliness, reliability and security but also provide a new approach for data-driven smart visual monitoring of power consumption. [ABSTRACT FROM AUTHOR]

Rice is part of many people's diet around the world, being the main energy source in some regions. Although fewer reports exist on the occurrence of mycotoxins in rice compared to other cereals, fungal contamination and the associated production of toxic metabolites, even at lower occurrence levels compared to other crops, are of concern because of the high consumption of rice in many countries. Due to the diversity of fungi that may contaminate the rice food chain, the co‐occurrence of mycotoxins is frequent. Specific strategies to overcome these problems may be applied at the preharvest part of the crop chain, while assuring good practices at harvest and postharvest stages, since different fungi may find suitable conditions to grow at the various stages of the production chain. Therefore, the aim of this review is to present the state‐of‐the‐art knowledge on such strategies in an integrated way, from the field to the final products, to reduce mycotoxin contamination in rice. [ABSTRACT FROM AUTHOR]

Abstract In the smart grid environment, demand response (DR) program has attracted considerable attention for industrial electricity consumers. There are many optimization problems involved in the DR programs especially the process of industrial power load scheduling. As a friendly interaction between utility companies and industrial electricity consumers, DR program plays an important role in smoothing the load curve, improving the reliability of the power grid and reducing the costs for electricity consumers. In this study, we first introduce some related concepts, including smart grid, Industrial Demand Response and the representations of the industrial production process. Then, the optimal scheduling models for industrial power load in the smart grid environment are presented, and the solving methods of the optimization models are discussed. Finally, the challenges are pointed out and discussed. Graphical abstract Image Highlights • Load scheduling problems with single and multi-objective are discussed. • Emissions, production constrains and microgrid are taken into account. • The models aim to accomplish minimal cost, maximal profit, and eco-friendliness. • Main challenges for future research are proposed in terms of three aspects. [ABSTRACT FROM AUTHOR]

Abstract Hydrothermal reservoirs commonly exist in association with fault activities. This study discusses the geothermal energy exploitation strategies in a fault-controlled geothermal system based on the Zhacang geothermal field in the northeastern Tibetan Plateau. The influence of well placement (including production depth, injection depth and well distance) and operation parameters (including injection temperature and production backpressure) on the heat production performance are evaluated by coupled thermal–hydraulic numerical modeling. Results indicate that a geothermal energy production of 1.67 MW can be obtained in the Zhacang geothermal field in 50 years, when the injection rate is 2.5 kg/s and injection temperature is 10 °C, with the injection depth at 1500 m, production depth at 300 m and well distance at 300 m. This optimized strategy is weakly affected by the terrestrial heat flux, because the heat transport in permeable fault zone is dominated by convection rather than conduction. Heat production increases with permeability in the conductive fault zone. The relationship between geothermal energy production and the associated natural and anthropogenic factors discussed in this study can help optimize heat extraction management in the other fault-controlled hydro-geothermal reservoirs. Highlights • General heat production strategies are discussed for a fault-controlled geothermal reservoir. • Performance assessment of the geothermal system is based on realistic geological conditions. • Sensitivities of heat production to natural and anthropogenic factors are investigated. [ABSTRACT FROM AUTHOR]

Abstract In this paper, a novel power generation system integrating a natural gas expansion plant with a geothermal organic Rankine cycle (ORC) was proposed. The paper begins with an introduction to the thermodynamic and economic models of the system. Secondly, contrastive analyses of three candidate working fluids were made, leading to the selection of R600 as the best fluid for the system, and the effects of gas pipeline parameters fluctuation on the system performance were originally investigated and analyzed based on the actual operating data of a natural gas PRS, located in Xiqing district, Tianjin, China. Finally, a multi-objective optimization for the system using R600 as working fluid was done to find the optimal evaporation temperature based on the TOPSIS decision-making method, and exergy loss analysis was accomplished at the optimal condition. The results indicated that the proposed system had a net profit of 3.97 M$ in the life time and a small payback period around 2.0 years at the optimal evaporation temperature of 45.5 °C where the system had a high thermal efficiency of 89.8% and exergy efficiency of 84.13%. Additionally, the condenser has the greatest potential to reduce the total exergy loss of the system. Highlights • A power system integrating a natural gas expansion plant with a geothermal ORC. • R600 is the most suitable working fluid for the system. • Effects of gas parameters fluctuation on the system performance. • A multi-objective optimization for the system with R600. [ABSTRACT FROM AUTHOR]

This paper examines the development and implementation of a communication structure for battery energy storage systems based on the standard IEC 61850 to ensure efficient and reliable operation. It explores this standard’s capability to define suitable data exchange with battery energy storage systems and the feasibility of implementation in the field. It also analyzes the extent to which standard IEC 61850′s information model and defined interfaces suffice to ensure communication that enables full integration of a battery energy storage system in an electrical (smart) grid. A data model compliant with the standard is developed and subsequently tested in prototype implementation among a control center, photovoltaic system and battery energy storage system. [ABSTRACT FROM AUTHOR]

The axial piston pump is an important industrial power element, and its performance directly affects the operation of the system. However, owing to its complex structure and harsh operational environment, the actual operational performance of the axial piston pump is difficult to be assessed accurately, which makes ensuring the normal operation of the hydraulic system difficult. To improve the evaluation method for an axial piston pump, a comprehensive performance evaluation system was proposed based on analytic hierarchy process (AHP), which could assess the performance of an axial piston pump on the basis of theoretical analysis, test, operator interaction, and application. Considering a model of load-sensitive axial piston pump with good operability as an example, the model development and simulation of the pump were carried out based on AMESim and the pump was tested using a developed performance test bed for axial piston pump. The weights of factors in the evaluation system were determined on the basis of the simulation results, analyses, and calculation. The above results were used to comprehensively analyze the tested pump and design a set of comprehensive performance evaluation software. The evaluation result was nearly identical to the actual usage, which verified the feasibility of the designed evaluation system. [ABSTRACT FROM AUTHOR]

Winemaking is a global industry that needs to advance with the times taking into consideration the developing drinking needs, tastes of human beings and the growing demand on the world's renewable energy sources. Climate changes have brought nowadays challenges of energy requirements, subsequent emissions and the detrimental effects facing the winemaking industry and mankind. Given its energy requirements, concomitant emissions and the pernicious effects, winemaking industry should bear the brunt of improving energy utilization efficiency and promoting the development and adoption of renewable energy utilization technologies. Various kinds of renewable energy are being used in winemaking industry worldwide, especially solar energy in the form of solar thermal and solar photovoltaic, which offer a clean solution to fossil fuels shortage and pollutant emissions caused by or involved in winemaking processes. The objective of this paper to present challenges facing solar energy utilization in winemaking by summarizing the status of solar energy utilization in wineries worldwide, by outlining the current solar energy profile of these wineries and by stressing the existing and potential application aspects of solar energy in winemaking. Considering the more rapid development of PV industry, PV chain and economic feasibility are analyzed. By taking China as an example, the comparison and asymmetry between PV production and active solar-related winemaking are stressed aimed at appealing to winemakers and policymakers to turn more to renewable energy like solar energy. Based on that, essential suggestions are provided, which are expected to extend solar energy systems for subsequent contributions to energy conversation, environmental protection and reduction of land occupation. [ABSTRACT FROM AUTHOR]

Current and future challenges of optimization in the process industry are discussed. The gap between academic research and industrial workflow is analyzed. Moreover, issues arising from the shift from conventional fossil fuels as both feedstock and energy source to nonconventional feedstocks (shale gas, tar sands, CO 2 and biomass) and penetration of intermittent renewable energy are discussed. This manuscript focuses mainly on offline model-based optimization of design and operation, including the generation and selection of promising process alternatives for new feedstocks in conceptual design, multi-objective optimization, the estimation of thermodynamic parameters of new intermediates and the optimization of process operation under the volatile availability of the new feedstocks and energy sources. Moreover, a number of opportunities and needs for research and development are identified, including the simultaneous optimization of feedstocks, processes and products and a production able to process a variety of feedstocks and to utilize energy when it is cheap. [ABSTRACT FROM AUTHOR]

Anaerobic digestion (AD) of biowaste can generate biogas with methane (CH 4 ) as energy source and contribute to sustainable municipal solid waste management in India. Characteristic municipal biowastes sampled seasonally from household, fruit and vegetable market and agricultural waste collection points in villages, towns and cities in Maharashtra were analysed to assess the potential as substrate for AD. The mean biochemical methane potential (BMP, at 37 °C) across seasons and community sizes was between 200–260, 175–240 and 101–286 NL CH4  kg vs −1 for household, market and agricultural biowaste, respectively. CH 4 yields were comparable in villages, towns and cities. Seasonal variations in CH 4 yields were observed for market and agricultural biowaste with highest values during pre-monsoon season. Results underpin that municipal biowaste is a suitable substrate for AD in India. However, low purity of available biowaste resulted in lower CH 4 yields compared to recent studies using source-segregated biowaste. [ABSTRACT FROM AUTHOR]

Concerns about environmental preservation instigate new investigations on alternative energy sources, such as proton exchange membrane fuel cells (PEMFCs). In order to avoid efficiency loss in PEMFC systems, at temperatures above 100 °C and minimize catalyst poisoning, anhydrous conditions are proposed, with substitution of water molecules by protic ionic liquids (PILs) as conducting medium for ions. PILs also feature excellent thermal stability. In this work, poly(ether sulfone) (PES), diethylmethylamine triflate ([dema][TfOH]) and titania (TiO2) or zirconia (ZrO2) based membranes were obtained and characterized, so that the filler effect on ion conductivity and polymer/PIL compatibility could be evaluated. XRD and TGA results indicated higher PES chain organization induced by the oxide networks, with thermal stability over 200 °C. These networks also contribute to better PIL retention in the membranes, as shown by TD‐NMR, and help improve ion conductivity, reaching values 160% higher than those found in samples containing just PIL. [ABSTRACT FROM AUTHOR]

In the contemporary history, the Middle East and China are the focus of global attention. Though Middle East has fought an ideological struggle with regard to religious extremism in the region, yet the quest for power energy sources cannot be overlooked. While Chinese policy frame, revolving around its approach of non-interference, economic development and a desire of having multi-polar global system is serious challenge for the US which on one hand, advocates democracy, human rights, but with the policy of intervention. Today, the world powers are competing each other for the supremacy of power resources where oil and gas are not an exception. China is the second largest consumer of world's oil after the United States (Bajpaee, 2006). China is making an effort to build an economic, political and military influence in the region without involving the military force. Though future will reveal many truths yet it is anticipated that a new triangular balance of power comprising of China, Saudi Arabia and Russia might emerge on the global scene, owing to their inter-connected dependencies. China is looking forward by pursuing the policy of wait and see for the appropriate moment This study primarily focuses on their bilateral relations and deals with China's Middle East policy, its increasing activities in the region and implications for Pakistan. For Pakistan, the nature of future relationship with Middle Eastern multi-dimensional crisis is very important because it is the "Arc of crisis". The neutral role of Pakistan in this situation is much hazardous, carrying both challenges and opportunities along with the security repercussions. [ABSTRACT FROM AUTHOR]

Industrial power systems, whether low-voltage or medium-voltage systems, are the backbone of any industrial facility. To keep production going and minimize downtimes, they are required to be very reliable. Therefore, it is important to deploy various protection systems to detect and react appropriately to any abnormal condition that can lead to a failure to deliver power or to a hazardous condition. Ground faults are the most common condition experienced by a power system. Hence, the ability to detect and react as needed quickly is paramount. The goal of this paper is to help protection engineers, engineering consultants, and power system operators to apply ground-fault protection systems correctly while also complying with local electrical codes. [ABSTRACT FROM PUBLISHER]

Generally waste heat, waste water and waste streams are available as industrial energy sources in industrial companies. Additionally, their roof areas can be used for solar energy harvesting. The energetic linking of industry and urban areas through the usage of industrial energy for covering the energy demand of the cities is hardly surveyed. Due to the lack of research concerning the symbiosis of industry and cities, no figures are available which enables an economic comparison with other energy production technologies. An economic assessment was carried out using four towns as examples. With the help of the annuity method, amortization times are determined. Additionally levelized costs for electricity and heat under different scenarios are calculated. They reach from 60 to 91 €/MWh for electricity and 25–38 €/MWh for heat. A sensitivity analysis takes into account possible price fluctuations. [ABSTRACT FROM AUTHOR]

A failure analysis investigation was carried out on the secondary Superheater tubes of a boiler unit in a steam power plant. The tubes, made of DIN-16CrMo4 steel, failed by bulging and rupture only after about three years of operation. Metallurgical investigations revealed that microstructural degradation had mainly occurred at the external (fireside) tube surface. Long-term overheating was identified as the root cause of the premature failure. [ABSTRACT FROM AUTHOR]

This paper intends to identify circuit parameters of an installed induction motor in an innovative way which is different from standard tests. In this paper, easily available motor manufacturer data is used by which rated output power, rated terminal voltage, full load efficiency, full load power factor, nominal speed, number of poles, and locked rotor current are provided. In order to estimate the parameters, nonlinear mathematical equations of motor are derived and iterative Gauss-Seidel method is used to solve them in MATLAB. Identified parameters are then transferred to MATLAB/Simulink model of the motor to simulate its performance during Star-Delta start. Validation of parameters is evaluated by comparing the result of Simulink with real-time measurement of an industrial Power Quality Analyzer. [ABSTRACT FROM AUTHOR]

The tropical surface wind speed in boreal winter reaches a maximum near Taiwan. This stable wind resource may be used for future clean energy development. How this surface wind energy source has changed in past 141 years is investigated using the 20th century reanalysis dataset and CMIP5 models. Our observational analysis shows that the surface wind speed experienced a weakening trend in the past 141 years (1871 - 2010). The average decreasing rate is around -1.4 m s-1 per century. The decrease is primarily attributed to the relative sea surface temperature (SST) cooling in the subtropical North Pacific, which forces a large-scale low-level anticyclonic circulation anomaly in situ and is thus responsible for the southerly trend near Taiwan. The relative SST trend pattern is attributed mainly to the greenhouse gas effect associated with anthropogenic activities. The southerly trend near Taiwan is more pronounced in the boreal winter than in summer. Such seasonal difference is attributed to the reversed seasonal mean wind, which promotes more efficient positive feedback in the boreal winter. The CMIP5 historical run analysis reveals that climate models capture less SST warming and large-scale anti-cyclonic circulation in the subtropical North Pacific, but the simulated weakening trend of the surface wind speed near Taiwan is too small. [ABSTRACT FROM AUTHOR]

Electric Vehicles (EVs) are viewed as an option to reduce the environmental impacts of Internal Combustion Engine Vehicles (ICEVs). EVs, however, also cause environmental impacts. To compare the impacts of EVs with the impacts of ICEVs, several Life Cycle Assessment (LCA) studies have been performed, showing that the results are largely dependent on the energy source. In the Brazilian case, however, the energy sources are different, considering that the electricity mix is mostly comprised of hydropower and that ICEVs can use ethanol. The main purpose of this study is to identify the environmental impacts of Battery Electric Vehicles (BEVs) in the Brazilian lightweight fleet, using LCA. A decisional approach was used, but, due to the lack of data, was focused on use phase, including energy consumption, whereas attributional data were used for the vehicle production stage. Government projections were used as the source of decisional data. The BEV considered was better for abiotic depletion, global warming, ozone layer depletion and fresh water aquatic ecotoxicity. In these categories, however, the lack of advance planning, leading to thermal electricity generation, could diminish BEVs benefits or make them worse than ICEVs. As for the other categories, at least one ICEV option performed better than the BEV. Vehicle production was also responsible for a good part of the impacts in many categories, so that early replacement of ICEVs with BEVs could also result in larger impacts. Public policies could target BEVs, but should encompass measures to reduce the impacts of the BEVs in the categories they perform worse than ICEVs. Among the limitations of this work are the use of attributional data for many of the processes, including vehicle production and disposal, and also the fact that second and third generation ethanol were not included. These could be dealt with in future research. [ABSTRACT FROM AUTHOR]

Meanwhile with increasing demand for energy sources in the world, hydropower plants can be considered as clean energy sources for sustainable development. Hydropower plant environmental impact is almost none. They are easy to construct and operate with much lower cost in comparison with other types of power plants. Currently in Iran, Conventional methods for determining hydropower plant potent location are very complicated and do not always eventuated to the best result. This study focuses on run of river projects and proposes a new methodology to spot hydropower plan best location according to specific engineering criteria, using ArcGIS and an algorithm developed in MATLAB. An economic analysis is then run upon engineering selected alternatives to assess their economic feasibility. For a case study, this methodology is applied for Sefidbarg basin in Nokhan area nearby the Kermanshah province. Nokhan area is a mountainous district with steep and durable rivers. Finally, four alternatives are suggested for hydropower plant location on Sefidbarg basin considering engineering criteria. Economic parameters are then calculated for these suggested hydropower plants to assess their economic feasibility and rank them according to their economy. This procedure is able to quickly survey vast areas for spotting best location for hydropower plant. [ABSTRACT FROM AUTHOR]

Power Quality (PQ) is a key issue for power systems measurement, operation, protection, security, planning and economy since it will lead to relay malfunction, aging, higher electricity costs and other disadvantages. This problem must necessarily be quickly monitored, investigated, and mitigated for security power systems operation. Therefore, real-time PQ analysis is an interesting research to be developed. One method for analyze this problem is Stockwell Transform (ST) widespread application in signal analysis. However, the high computational complexity of ST is a challenge that needs to be solved. Fast Stockwell Transform (FST) has lower computational complexity compared to ST. This paper proposes Power Quality Analysis (PQA) using the FST method and its implemented in industrial power systems. The FST is used to extract the PQ signal from the time-frequency domain. The implementation of FST using STM32F407VGT6 microcontroller is introduced. The simulation and application result is compared to the several common methods to validate the accuracy and efficiency of the proposed algorithm. The simulation results demonstrate that this algorithm can accurately detect the harmonic, voltage sag, voltage flicker, oscillatory transient, notch and spike. The experiment results of the harmonic are compared with the well known commercial product, showing a good agreement. [ABSTRACT FROM AUTHOR]

This article examines the impact the oil boom has had on crime and disorder in North Dakota. Particular attention is paid to the methods used to analyze these impacts. Several quantitative analyses, includingt-tests and regressions, were performed and critiqued. Overall, few significant relationships were found that could link the oil boom to increases in crime and disorder. In addition, this article introduces location quotients as an alternative method to examine crime and disorder in boomtown settings. The results suggest that the impact of the boom was localized in that different counties experienced differential crime and disorder impacts. [ABSTRACT FROM AUTHOR]

Biodiesel is a valuable alternative to fossil fuels and many countries choose biodiesel as an unconventional energy source. A large number of investigations have been done on microalgae as a source of oil production. In recent years, wastewater pollutions have caused many ecological problems, and therefore, wastewater phycoremediation has attracted the international attention. This paper studied the cultivation of Chlorella vulgaris in a crude oil polluted environment for biodiesel production. Intended concentrations were 10 and 20 g per liter (crude oil/water) at two times. The results showed that the growth of C. vulgaris was improved in wastewater and the maximum amount of dry mass and oil was produced at the highest concentration of crude oil (0.41 g and 0.15 g/l, respectively). In addition, dry mass and oil yield of the microalga were significantly enhanced by increasing the experiment duration. [ABSTRACT FROM AUTHOR]

Electricity systems in Chile are characterized by a variable hourly demand in the central grid and an almost constant demand in the northern grid, which require different operation strategies for solar power plants depending on their location. Hybridizing a CSP plant with a PV system can increase the overall plant capacity factor by allowing thermal energy to be stored while the PV plant is in production and thus help to achieve a fully dispatchable solar electricity production system. A power generation and economic analysis of two hybrid CSP + PV plant models were developed considering a range of plant capacities based on parabolic trough or central receiver plants, combined with a PV system. Environmental conditions were considered for a site in the Atacama Desert, which is a hotspot of solar energy development in the country and shares the solar radiation characteristics of northern Chile. The study conducts a parametric analysis and optimization of the storage and power block sizes for the CSP plants in terms of the levelized cost of energy (LCOE), when the nominal capacity of the PV plant is varied. The annual production of the plants is calculated using the Transient System Simulation program (TRNSYS), which uses a new component library developed for that purpose. From the results of the simulations, the high potential for hybrid CSP + PV plants in the Atacama Desert is clear, because the high levels of irradiation available in northern Chile provide a competitive electricity cost, allowing investors to access PPA contracts at competitive prices and achieving competitive costs with respect to other energy sources. [ABSTRACT FROM AUTHOR]

We examined 20 renewable energy auctions in India and elsewhere to answer two questions: first, have auctions been effective; and second, how can they be designed to achieve India’s renewable energy targets? The significant contributions lie in the larger sample size, use of secondary and primary research, and application of quantitative and qualitative analysis. We found that auctions are almost always cost-effective , with savings up to 58% from baseline feed-in tariffs. However, auctions may not always be deployment-effective , with only 17% of the auctions with greater than 75% deployment. We then examined how to best design auctions by assessing seven major risks, and found the following: first, for every 1% increase in total risk, deployment effectiveness decreased by 2% points; second, project specific risks have 60% greater impact than auction specific risks; and third, deployment effectiveness is most affected by auction design, completion, and financial risks. We also found that effectiveness of auctions in India can be improved by ensuring competition, improving transmission infrastructure, providing payment guarantees, using pay- as -bid auctions, including stringent penalties for delays, and introducing auctions in a controlled manner. [ABSTRACT FROM AUTHOR]

In this study, biogas production through anaerobic digestion of food waste was investigated by applying four factor-four level Taguchi design under experimental conditions such as solid concentration (5%-12.5% TS), pH (6-9), temperature (30-60 °C), and co-digestion of poultry waste (10%-40%). Multi-objective techniques such as grey relational analysis (GRA) and multi-variate principal component analysis (PCA) were used to determine the optimal level of process parameters. The interactive effect of process conditions on the biogas yield was studied with multi-response performance index. The obtained results were analyzed by analysis of variance and the percentage contributions of each parameter were determined. Optimum conditions for maximizing the biogas yield and volatile solid removal efficiency were determined using hybrid GRA-PCA technique and it was found to be solid concentration of 7.5% TS, pH of 7, temperature of 50 °C, and co-digestion of 30%. Supremacy of the chosen hybrid technique is confirmed from the confirmation experimental output. [ABSTRACT FROM AUTHOR]

Rapid, field-based assessments of rock hardness are required in a broad range of geomorphological investigations where rock intact strength is important. Several different methods are now available for taking such measurements, in particular the Schmidt hammer, which has seen increasing use in geomorphology in recent decades. This is despite caution from within the engineering literature regarding choice of Schmidt hammer type, normalization of rebound ( R-) values, surface micro-roughness, weathering degree and moisture content, and data reduction/analysis procedures. We present a pilot study of the use of an Acoustic Energy Meter (AEM), originally produced, tested and developed within the field of underground mining engineering as a rapid measure of rock surface hardness, and compare it with results from a mechanical N-Type Schmidt hammer. We assess its capabilities across six lithological study sites in southeast Queensland, Australia, in the Greater Brisbane area. Each rock exposure has been recently exposed in the 20th/21st century. Using a 'paired' sampling approach, the AEM G-value shows an inverse relationship with Schmidt hammer R-value. While both devices show variability with lithology, the AEM G-values show less scatter than the Schmidt hammer. We conclude that each device can contribute to useful rock hardness testing in geomorphological research, but the AEM requires further field testing in a range of environments, and in particular on older and naturally-exposed rock surfaces. Future evaluations can extend this pilot study by focusing on sampling procedures, energy sources, and data reduction protocols, within the framework of a comparison study with other rock hardness testing apparatus. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper aims to show the current state of energy consumption and accompanying energy indicators in the public building sector in the Autonomous Province of Vojvodina, Serbia. The public building energy consumption data (healthcare, administration and schools) was collected by surveys supported by on-site measurements, calculations and interviews with people responsible for energy monitoring. Statistical processing of the collected data on the real extent and manner of energy usage in public buildings in Vojvodina was used. This paper presents energy indicators which are on average three times higher than allowed by Serbian Ordinance and what is currently present in neighboring European Countries. It is of the utmost importance to use this data and its implications as a catalyst for the implementation of energy management in the public building sector and an increase in energy efficiency. [ABSTRACT FROM AUTHOR]

Instead of direct measurement, ground bearing capacity has been predicted by various equations in the literature. In this study, ground vibrations produced by a certain energy source were measured at eight different locations of three open-pit mines (Divriği Open-Pit Iron Mine, Kangal Open-Pit Coal Mine, and Ulaş Open-Pit Celestite Mine) in Turkey for the assessment of ground bearing capacity. Particle velocity values were evaluated considering the distance and the direction of the measurement. The paper reports a study depicting the use of vibration tests as a quick, cheap, and easy means of establishing a preliminary bearing capacity. The regression analyses indicated a clear relationship between the bearing capacity of rock formations ranging from weak to strong and the peak particle velocity with good performance indices (r², RMSE, VAF). The highest correlation coefficient was found at 0.97 where the distance to energy source was 7 m. Therefore, equation at a distance of 7 m was suggested for bearing capacity prediction. [ABSTRACT FROM AUTHOR]

Using the standard methods for the determination of approximate analysis, ultimate analysis, chemical composition, heating value and inorganic elements, the thermochemical properties of three air-dried napier grass samples have been analyzed in the present study. The results showed that thermochemical characteristics of all samples were found to be similar. The energy grass obviously comprised a large percentage of volatile matter at 72.72 ± 0.73 wt%. The molar rations of hydrogen to carbon (H/C) ranging from 1.60 to 1.73 are close to those of cellulose (H/C = 1.67) and hemicellulose (H/C = 1.6), which was in accordance with its higher heating value (16.3 MJ/kg). However, the contents of nitrogen and chlorine were significantly high, suggesting that the emissions of acidic gases and chlorinated organics from biomass-to-heat facilities will arouse concern. Based on the 100,000 ha fallow farmland cultivated into the energy grass in Taiwan and the Tier 1 method recommended by the Intergovernmental Panel on Climate Change, the environmental benefit of mitigating CO2emissions and the economic benefit of oil equivalent were calculated to be around 5.0 × 106Gg/yr and 1.1 × 107barrels/yr, respectively. [ABSTRACT FROM AUTHOR]