Comparison Of Energy Consumption Research Articles

Air-conditioning in low income households; a comparison of ownership, use, energy consumption and indoor comfort in Australia

Air-conditioning and energy use are important topics at present, particularly in Australia where rising electricity prices and a changing climate are placing increasing strain on one of the world's longest interconnected electricity networks. At the same time, there is a concern that some consumers are particularly vulnerable to these changes. This study analyses three data-sets consisting of energy use and survey information from several thousand households, with the aim of better understanding the ownership, use, energy consumption and comfort outcomes related to air-conditioning in low income households in Australia. The findings suggest that low income households do tend to own different types of air-conditioning appliances, are more likely to reside in different types of buildings, be located in non-metropolitan areas, and belong to an older age demographic. These differences may have a greater influence on air-conditioning use behaviours (including energy use and comfort), than simply the fact that a household has a low income. Hence it is suggested that potential vulnerability measures should not be based on income alone.

Prediction, comparison and analysis of comfort level and energy consumption of a passively remodeled dwelling based on BP neural network computation

Many ordinary dwellings are not well built in the vast rural areas of China, with poor comfort level and high energy consumption. The China Resources Charity Foundation funded the renovation of more than 200 farmhouses. Compared with the BP neural network model established with the measured data, the BP neural network model established with the simulated data can more quickly estimate the energy saved by the renovation measures of rural dwellings and the improved indoor environment, which is very necessary for the government and enterprises to make decisions to help. In this paper, one of the renovated houses (No. 285) was selected for tracking measurement before and after renovation to obtain real indoor environment and energy consumption data. Simulation software (DesignBuilder) was used to simulate the other 36 renovated houses in order to train the BP neural network model. The energy consumption of No. 285 was calculated by using the trained BP neural model, and the calculated results were compared and analyzed with the simulated data and measured data. Results show that the BP neural network model after training is better than the simple energy consumption simulation software in energy consumption prediction, but there are still errors from the actual measurement values. Regardless of software predictions or actual measurements, the results show that the renovation measures have indeed exerted a very positive impact. As to the overall trend, the software predictions are the same as of the actual measurements, and the variance of day and night temperature variance and the annual extreme values are greatly reduced.

Effect of localized exterior convective heat transfer on high-rise building energy consumption

The energy consumption analyses of high-rise buildings have some fundamental limitations that include the treatment of building size, changes in microclimate parameters with altitude, and the uncertainties associated with the existing building facade convective heat transfer coefficients correlations (CHTC). This study investigates the effects of these parameters on the energy consumption by individual rooms at a different location as part of a 100 m high-rise building, exposed to different weather conditions, having a different window-to-wall ratio. In the first part of the study, representative new-CHTC at the windward facade of the building is generated by using CFD simulations. In the second part of the study, comparative energy consumption assessment is carried out using the newly generated CHTC and other commonly used correlations by using EnergyPlus. The result shows that for high-rise building with 100% WWR exposed to a windy microclimate (such as Boston, MA), a deviation of 11.2% and 4.7% on annual heating and cooling energy consumption, respectively, have been observed. Further, the energy consumption of each room throughout the building height was also investigated to investigate the effect of building height. Compared to a room located at the mid-height (15th floor), the annual heating consumption on a room located at the 5th floor room was 7.8% lower and a room located on the 25th floor room the consumption was 7.6% higher. In summary, this study highlights the importance of accurate local CHTC generation to enhance thermal comfort in individual rooms and to optimize overall building energy consumption.

Estimation of Minimum Energy Consumption Index in a Protected Farm Using Bacteria Foraging Optimization Algorithm

This article estimates the minimum energy consumption index in a single story protected farm which would suggest the condition of minimum energy consumption or loss condition. The analytic hierarchy process (AHP), weighted sum method (WSM) and weighted product method (WPM) are used for relative ranking of four energy consumption indicators viz., water pumping, light supplement, CO2 balancing and cooling-heating under three criteria viz., cropping area, daily crop water, and indoor environment. The minimum, maximum and average energy consumption index was predicted by the bacteria foraging optimization (BFO) algorithm and the group method of data handling (GMDH). The minimum energy consumption index (1.4174) predicted by the BFO algorithm gives higher prediction compared energy consumption index (1.114) predicted by the GMDH algorithm.

COST EFFECTIVE OPERATION OF HVAC SYSTEM UNDER THERMAL DISTURBANCE

Varying cooling load requirements in HVAC system become a major concern to many consumers because of the additional cost of electricity. The cooling load variation of HVAC system usually occurs when the domestic house door is frequently kept open for prolonged durations, which is particularly important in hot seasons. The present study, addresses a comparison of energy consumption due to the thermal disturbance during domestic house door  keep opened for various duration when the Variable Frequency Driver (VFD) and ON/OFF controllers are installed in HVAC system. The experiments are carried out in two identical houses during six warm days in a hot season where the outdoor temperatures have similar patterns throughout the days. The energy response of HVAC system is analysed incorporating the thermal and the electricity consumption data because of the change of the indoor temperature during opening of the house main door. The cost analysis is carried out and it is extended to include several repeats of door opening durations. It is the first time demonstrated that the energy consumption for HVAC system increases dramatically when the house main door is kept opened for several times in a day. The energy consumption and additional cost increase significantly for the case when the period of the main door opening is extended. In this case, VFD A/C controller unit achieves more energy savings than that of ON/OFF A/C controller unit.

Electro-irradiated technologies for clopyralid removal from soil washing effluents

In this work, electrolysis and electro-irradiated technologies, i.e. sonoelectrolysis, photoelectrolysis and photosonoelectrolysis have been evaluated in order to improve the biodegradability of soil washing effluents polluted with the herbicide clopyralid. Results obtained showed that simple electrolysis with carbon felt anodes improved the biodegradability of the effluent and that combination of electrolysis with irradiation technologies lead to very different operative results. Photoelectrolysis produced a synergistic effect in clopyralid removal and mineralization, while sonoelectrolysis and photosonoelectrolysis did not generate any positive effect, showing antagonisms. Regarding the biodegradability of the effluents, photoelectrolysis was the only technology which demonstrated a significant enhancement; nevertheless, it has associated an important energy consumption in comparison to simple electrolysis processes.

A bottom-up analysis of energy efficiency improvement and CO2 emission reduction potentials for the swiss metals sector

The Swiss metals sector, comprised of manufacturing basic metals and fabricated metal products, is responsible for nearly 14% of total final energy (TFE) demand of the Swiss industry, making it one of the major energy consuming industrial sectors. This study investigates the current potential for energy efficiency (EE) improvement and CO2 abatement in the Swiss metals sector by means of bottom-up cost curves. Based on the comparison of Specific Energy Consumption for the processes applied in the Swiss metals sector with those of the best available techniques, the maximum technical EE potential for Swiss metals sector is estimated at 19%, while the economic EE potential is in the range of 11%–15%. The corresponding economic CO2 abatement potential is estimated at 6%. Among all measures, EE improvement of the rolling process was found to have the largest potential for TFE savings in the Swiss metals sector. The detailed insight into the EE gap and techno-economically feasible EE improvement solutions for the Swiss metals sector identified in this study will help to overcome the techno-economic barriers in implementing best practices in the high value-added metals sector.

Analysis of energy consumption profiles in residential buildings and impact assessment of a serious game on occupants’ behavior

The paper has a focus on energy consumption habits, trends and intervention strategies in residential buildings, mainly through the serious game approach with a combination of direct consumer feedback through smart metering. More than 150 homes in France and Spain have been involved in the research experiment and the consumption habits of approximately 50 homes were deeply analyzed. The applied methods, processes, results and findings of the monitoring data analysis are presented in the paper with two aims. First, consumption profiles and trends were determined for apartment homes with regard to heating, domestic hot water and electric consumption. Second, the impact of a serious game experiment was assessed comparing energy consumption, indoor air temperature and users’ habits (based on questionnaires) before and after launching the experiment.

Response to comments on “comparison of energy consumption in desalination by capacitive deionization and reverse osmosis”

Response to comments on “comparison of energy consumption in desalination by capacitive deionization and reverse osmosis”

Quantification of Energy Saving Potential for A Passenger Train Based on Inter-Run Variability in Speed Trajectories

Passenger train energy consumption is dependent on speed trajectories. The variability of passenger train energy consumption owing to the variability in speed trajectories can help identify ways to reduce train energy use via improved operations. Empirical fuel use data from a portable measurement emission measurement system (PEMS) and empirical speed trajectories measured using a global positioning system (GPS) receiver were used to verify and quantify real-world energy consumption variability and the variability in empirical speed trajectories, respectively. To identify potential realistic speed trajectories that can lead to energy saving (i.e., eco-driving), a Markov chain based speed trajectory simulator was used to simulate inter-run variability in speed trajectories. An energy index model (EIM) was used to compare energy consumption among different speed trajectories. The results show inter-run variability in fuel use associated with inter-run variability in the empirical speed trajectories. There is also inter-segment variability in fuel use related to the segment length and grade. The Markov chain based speed trajectory simulator can simulate realistic inter-run variability in speed trajectories based on calibration using empirical speed trajectories. The number of empirical speed trajectories used for simulator calibration affects the range of simulated inter-run variability. The EIM provides an accurate estimation of the empirical fuel use. Eco-driving, such as reducing the peak speed, can reduce energy consumption without compromising travel time. The methodology shown in this study is not system-specific and can be applied to other passenger train systems.

Comments on “Comparison of energy consumption in desalination by capacitive deionization and reverse osmosis”

Comments on “Comparison of energy consumption in desalination by capacitive deionization and reverse osmosis”

An Online Extrusion-compression Molding Method to Produce Wood Plastic Composite Packaging Boxes

Wood plastic composites are widely used to manufacture profiles by extrusion but rarely applied to make products by injection or compression for its poor flowability. Wood plastic composite packaging boxes were manufactured by both self-designed online extrusion-compression and traditional injection molding methods with different formula. The mechanical properties, buckling deformation, production capacity and final passed yield of packaging boxes and energy consumption was investigated with the two different methods. We find that the filling of bamboo fiber into polyolefins improves tensile strength but brings down impact strength in both processing method. However, for online extrusion-compression molding we can obtain a better tensile and impact strength. With the increase of bamboo fiber concentration and decrease of HDPE/PP mass ratio the buckling deformation declines, and a smaller buckling deformation can be obtained by the online extrusion-compression molding with respect to tradition injection molding. The comparison of energy consumption between the two processing methods reveals that it is a cost-effective way to manufacture wood plastic products, saving about 29.81% energy compared with traditional injection molding. Online extrusion-compression molding technique can be widely used to manufacture wood plastic composite products of irregular structure and large-format.

Estimating Energy Consumption of Cloud, Fog, and Edge Computing Infrastructures

In order to improve locality aspects, new Cloud-related architectures such as Edge Computing have been proposed. Despite the growing popularity of these new architectures, their energy consumption has not been well investigated yet. To move forward on such a critical question, we first introduce a taxonomy of different Cloud-related architectures. From this taxonomy, we then present an energy model to evaluate their consumption. Unlike previous proposals, our model comprises the full energy consumption of the computing facilities, including cooling systems, and the energy consumption of network devices linking end users to Cloud resources. Finally, we instantiate our model on different Cloud-related architectures, ranging from fully centralized to completely distributed ones, and compare their energy consumption. The results show that a completely distributed architecture, because of not using intra-data center network and large-size cooling systems, consumes between 14 and 25 percent less energy than fully centralized and partly distributed architectures, respectively. To the best of our knowledge, our work is the first one to propose a model that enables researchers to analyze and compare energy consumption of different Cloud-related architectures.

Comparison of Energy Consumption and CO2 Emission for Three Steel Production Routes—Integrated Steel Plant Equipped with Blast Furnace, Oxygen Blast Furnace or COREX

High CO2 emissions and energy consumption have greatly restricted the development of China’s iron and steel industry. Two alternative ironmaking processes, top gas recycling-oxygen blast furnace (TGR-OBF) and COREX®, can reduce CO2 emissions and coking coal consumption in the steel industry when compared with a conventional blast furnace (BF). To obtain parameters on the material flow of these processes, two static process models for TGR-OBF and COREX were established. Combining the operating data from the Jingtang steel plant with established static process models, this research presents a detailed analysis of the material flows, metallurgical gas generation and consumption, electricity consumption and generation, comprehensive energy consumption, and CO2 emissions of three integrated steel plants (ISP) equipped with the BF, TGR-OBF, and COREX, respectively. The results indicated that the energy consumption of an ISP with the TGR-OBF was 16% and 16.5% lower than that of a conventional ISP and an ISP with the COREX. Compared with a conventional ISP, the coking coal consumption in an ISP with the TGR-OBF and an ISP with the COREX were reduced by 39.7% and 100% respectively. With the International Energy Agency factor, the ISP with the TGR-OBF had the lowest net CO2 emissions, which were 10.8% and 35.0% lower than that of a conventional ISP and an ISP with the COREX. With the China Grid factor, the conventional ISP had the lowest net CO2 emissions—2.8% and 24.1% lower than that of an ISP with the TGR-OBF and an ISP with the COREX, respectively.

Development and experimental validation of a TRNSYS model for energy design of air-to-water heat pump system

The object of this research work is the comparison of the annual primary energy consumption of different types of heating systems, using two different calculation methods. The TRNSYS 18 software makes use of dynamic simulation, while the WinWatt software calculates according to the Hungarian implementation of EPBD (Decree No. 7/2006). There were differences in results which could be caused by the more precise calculation of the TRNSYS software. Differences were shown also in the weather data used by the two computer tools that had one of the most important effects on the results according this investigation. The number of heating degree days used by TRNSYS is 10% less, than that the Hungarian decree provides. Using the yearly measured energy consumption data given by the inhabitant of the investigated family house, the validation of the developed dynamic building energy simulation model by TRNSYS could be also achieved with good agreement.

What is the efficiency of electro-generation of chlorine with a solid polymer electrolyte assembly?

The use of a solid polymer electrolyte (SPE) in an anode/SPE/cathode sandwich has emerged as a promising electrochemical configuration to reduce the terminal voltage and thus energy consumption during electrolysis. This study for the first time investigates and compares the efficiency of the electrochemical chlorine production process as well as estimates and compares energy consumption with and without a SPE assembly in the electrolytic cell. Results indicate that at the same current density of 12.5 mA/cm2, Cl2 production rate and instantaneous current efficiency (ICE) were higher when no SPE was used than with a functional SPE, most likely because the SPE occupied one side of the electrode surface, thus limiting the contact of Cl− with its surface to generate Cl2. However, increasing the current density to 31.25 mA/cm2 with a functional SPE resulted in an almost equal Cl2 production rate to that at 12.5 mA/cm2 without a functional SPE, and still the energy consumption per mass of produced Cl2 was the same, although lower ICE was achieved. The study also further investigated the effect of flowrate, and the influence of initial Cl− concentration and the initial pH for the system with the functional SPE.

Comparison of energy consumption in desalination by capacitive deionization and reverse osmosis

Capacitive deionization (CDI), which is based on the electrosorption of ions by porous electrodes, is an emerging technology for brackish water desalination. Understanding the key drivers of energy consumption in CDI and benchmarking CDI with reverse osmosis (RO), the current state-of-the-art for brackish and seawater desalination, is crucial to guide the future development of desalination technologies. In this study, we develop system-scale models to analyze the energy consumption and energy efficiency of CDI and RO over a wide range of material properties and operating conditions. Using our models, we explore how the energetic performance of CDI and RO compare as a function of feed salinity, water recovery, salt rejection, and average water flux, which is normalized by electrode and membrane area in CDI and RO, respectively. Our analysis shows that RO is significantly more energy efficient than CDI, particularly when targeting higher salinity feed streams and higher salt rejection values. For brackish water with a salt concentration of 2000 mg L−1, achieving 50% water recovery and 75% salt rejection, with an average water flux of 10 L m−2 h−1 using CDI requires a specific energy consumption of 0.85 kWh m−3, more than eight times that of RO (0.09 kWh m−3). Importantly, our results also indicate that current efforts to improve electrode materials can only marginally reduce the energy consumption of CDI. We conclude with a discussion highlighting other important factors, such as capital cost, electrode stability, and membrane fouling, which affect the efficacy of CDI and RO for low-salinity desalination.

Simulation study using building-design energy analysis to estimate energy consumption of refrigerated container

Refrigerated containers account for half of the total electricity consumption by storage yards and that this is expected to increase continuously each year. A refrigerated container is a special cargo container equipped with an integral refrigeration unit. The amount of power consumption of the refrigerated container will change depending on many external variables. Environmental factors mainly solar radiation received on the container walls caused surface temperatures increase will then affect the power consumption. This paper provides a simulation study on the estimation of energy consumption of refrigerated container. The simulation model performed on the building-design energy analysis used Integrated Environmental Solution (IES) software packages. The geometry of simulation model considers the actual dimension of refrigerated container consists of insulation walls in the three-dimensional analysis. Physical properties of the insulation walls and environmental factors used weather data are applied to the simulation model as parameter inputs. Estimation of energy consumption of the model based on the calculation of cooling load from the object considers the thermal effect from the sun energy. The measurement data from the experimentation was conducted by Shinoda and Budiyanto (2016) used as validation of simulation model. The comparison of energy consumption from simulation and measurement shows in shows in good agreement.

The Quantification and Reporting of Negawatt-Hours with Flexible Energy Conservation Measure Verification Software (ECM-Tool)

In order to promote digital innovations in the field of energy use and monitoring in all end customer sectors, the Federal Ministry for Economic Affairs and Energy (BMWi) has launched the “Pilotprogramm Einsparzähler” in 2016. The program promotes the development of digital platforms following the “Efficiency First” principle, focusing not on individual projects but on the establishment of a business model. smartB successfully applied for subsidies for the development of a software tool, the architecture of which is the content of this open source paper. The tool applies a multivariate regression-model to model a given system’s energy consumption (significant energy uses or SEUs), adjusted to relevant external factors (e.g. weather) and given output levels or product properties. Thereby comparing energy consumption before and after an energy conservation measure (ECM), the tool allows for a quantification and verification of achieved energy savings as laid out in international standards for energy management (ISO, 2014). Achieved energy savings induced by an ECM and energy efficiency improvements cannot be measured directly. We use the term “negawatt-hour”, defined as a unit of energy saved as a direct result of energy conservation measures. International norms provide accepted standards to derive quantified savings in negawatt-hours from a qualified comparison between consumption before and after an ECM, as presented at the beginning of the paper.

Eco-friendly machining using retrofitted cryogenic machining system

Adoption of greener machining techniques shall offer Indian industry a cost-effective route to improve its economic, environmental, and social footprint when it comes to cutting aerospace-grade intractable materials. Cryogenic machining is one such technique which uses an advanced method to deliver liquid nitrogen (LN2) (at -321° F) directly to the cutting edge enabling substantially faster processing speeds and increased tool life compared to conventional cooling methods. This results in higher throughput and reduced process energy demand, thus improving the efficiency of the cutting process. Further, the retrofitting ability of cryogenic systems mean they can be paired-up with in-house machining centers, making them an easy to use low-cost solution. This study presents the comparison of process energy consumption in the dry and cryogenic turning of Ti-6Al-4V. A hybrid design of experiments (DoE) is considered for the machining trials - this consists of a combination of full factorial DoE and Taguchi method to identify the influence of cutting process parameters on the process energy consumption in dry and cryogenic machining. Results show that cryogenic machining is more effective in achieving higher material-removal-rate when compared to dry machining.