Life Cycle Energy Consumption Research Articles

Research on comparative advantages of SPV pumping irrigation systems

Agricultural production relies heavily on irrigation, and water pumping for irrigation consumes a great amount of electricity every year in China. Meanwhile, more land in remote areas is barren because of lack of electricity and access to irrigation. Till now, most research works have been focused on the technological aspects of SPV irrigation system, very few studies were reported on economic and financial aspects of the system. The main barrier to promotion and application of SPV irrigation systems seemed the high initial investment. To analyse and clarify the comparative advantages of SPV facilities, the life cycle cost, energy consumption and pollution emission of pump stations powered by SPV, electricity and diesel was calculated respectively through a case study. The initial investment ratio of SPV, electricity and diesel pump station is 12.7:9.3:1, while the life cycle cost ratio of them becomes to 1:1.59:1.88, the SPV turned out to be economical, energy saving and environmental friendly. Policy suggestions on encouraging the construction of photo-electric complementary pumping stations and financial support to water users are put forward to make good use of SPV systems and release the financial burden from the initial investment.

Assessment of the Life Cycle Energy Efficiency of a Primary School Building in Turkey

Energy efficiency has become a crucial part of human life, which has an adverse impact on the social and economic development of any country. In Turkey, it is a critical issue especially in the construction sector due to increase in the dependency on the fuel demands. The energy consumption, which is used during the life cycle of a building, is a huge amount affected by the energy demand for material and building construction, HVAC and lighting systems, maintenance, equipment, and demolition. In general, the Life Cycle Energy (LCE) needs of the building can be summarised as the operational and embodied energy together with the energy use for demolition and recycling processes.Besides, schools alone are responsible for about 15% of the total energy consumption of the commercial building sector. To reduce the energy use and CO2 emission, the operational and embodied energy of the buildings must be minimised. Overall, it seems that choosing proper architectural measures for the envelope and using low emitting material can be a logical step for reducing operational and embodied energy consumptions.This paper is concentrated on the operating and embodied energy consumptions resulting from the application of different architectural measures through the building envelope. It proposes an educational building with low CO2 emission and proper energy performance in Turkey. To illustrate the method of the approach, this contribution illustrates a case study, which was performed on a representative schoold building in Istanbul, Turkey. Energy used for HVAC and lighting in the operating phase and the energy used for the manufacture of the materials are the most significant parts of embodied energy in the LCE analyses. This case study building’s primary energy consumption was calculated with the help of dynamic simulation tools, EnergyPlus and DesignBuilder. Then, different architectural energy efficiency measures were applied to the envelope of the case study building. Then, the influence of proposed actions on LCE consumption and Life Cycle CO2 (LCCO2) emissions were assessed according to the Life Cycle Assessment (LCA) method.

Life Cycle Energy Assessment of a School Building under Envelope Retrofit: An Approach towards Environmental Impact Reduction

Energy efficiency of existing buildings is a concept to manage and restrain the growth in energy consumption and one of the crucial issues due to the magnitude of the sector. Educational buildings are in charge of about 15% of the total energy consumption of the non-residential building sector. However, not only operational but also embodied energy of a building should be reduced to get the overall benefits of energy efficiency, where, using energy efficient architectural measures and low emitting materials during every retrofit action can be a logical step. The majority of buildings in Turkey and EU was built earlier than the development of the energy efficiency in the construction sector, hence, without energy retrofit, consume an enormous amount of energy that can be averted significantly by the implementation of some even not advanced retrofit measures. Furthermore, demolishing of a building to construct a new one is not a rational approach concerning cost, time and environmental pollution. The study has been focused on the impact assessment of the various architectural scenarios of energy efficiency upgrading on the Life Cycle Energy Consumption (LCEC) and Life Cycle CO2 (LCCO2) emission. Within the scope of the study, a primary school building is selected to be analysed. Through analysis, the total embodied and operational energy use and CO2 emission regarding the life cycle phase of the building is quantitatively defined and investigated in the framework of life cycle inventory. The paper concentrates on the operation and embodied energy consumption arising from the application of a variety of measures on the building envelope. An educational building with low LCCO2 emissions and LCEC in Turkey is proposed. To exemplify the approach, contributions are applied to a case study in Istanbul as a representative school building. The primary energy consumption of the case study building is calculated with a dynamic simulation tool, EnergyPlus. Afterwards, a sort of architectural energy efficient measures is implemented in the envelope while the lighting and mechanical systems remain constant. The energy used in the production and transportation of materials, which are the significant parts of the embodied energy, are taken into account as well.

Life cycle energy consumption analysis and green manufacture evolution for the papermaking industry in China

Life cycle energy consumption for the papermaking industry is investigated and a method to achieve the GHG emission reduction target is proposed.

Application of LCA in Expressway Energy Consumption Analysis in South China

In order to quantify the life cycle energy consumption of highways, life cycle assessment method is adopted to quantitatively analyze the energy consumption of a bridge-based expressway in South China. The total life cycle energy consumption was 1343967 tce, while the energy consumption per functional unit was 18733.86 tce/km. In addition, the proportion of the life cycle energy consumption for raw material production, construction and transportation was 71.90%, 13.64% and 14.47%, respectively. As data analysis shown, cement and steel bars have the greatest impact on energy consumption, the energy-saving measures during the construction phase should focus mainly on electricity and diesel, while during the operation phase should focus on controlling the power consumption. Based on the results, a series of energy-saving measures are proposed from the perspective of material-saving, energy-saving and management-strengthen.

A new approach to determine insulation material and thickness from a life-cycle perspective

Energy-efficient retrofitting of buildings is an important topic for the future world. Adding thermal insulation to the building envelope is the most common and well-known measure, but existing strategies for energy-efficient retrofits do not consider the life-cycle energy consumption and carbon dioxide (CO2) emissions of the insulation materials. This paper introduces a new approach for selecting the optimum insulation material and thickness based on life-cycle energy consumption and carbon dioxide emissions. The approach was applied to a multi-storey residential building located in İzmir, Turkey, which has a Mediterranean climate, and the results are compared with the same building in Erzurum, Turkey, which has a cold climate. The comparison reveals the effect of thermal insulation on energy consumption and carbon dioxide emissions. The results show that increasing thermal insulation thickness provides less energy efficiency in the Mediterranean climate than in the cold climate. In addition, if the thickness is not optimised according to the insulation material, the life-cycle carbon dioxide emissions and energy consumption may increase contrary to expectations. Extruded polystyrene insulation with 3 cm thickness for the Mediterranean climate and rock wool insulation with 9 cm thickness in cold climate have the optimum life-cycle energy and carbon dioxide emission performance for the case-study building.

Analysis of the impacts of retrofit actions on the life cycle energy consumption of typical neighbourhood dwellings

The residential sector is one of the most significant energy consumers and therefore contributes significantly to climate change. A study of not only the use of energy during the operation but also the associated consumption and emissions in the life cycle is required. One way to reduce life cycle energy consumption is through retrofitting existing buildings. This study analysed the energy consumption and its greenhouse gas emissions after applying five sustainable retrofit measures. For this purpose, two typical neighbourhood dwellings were chosen, located in the city of Vitória, in the state of Espírito Santo, Brazil. The analysis was conducted for the pre-operational and operational stages. Using pre-established standards, the energy of the building materials that compose the dwellings was calculated as well as the consumed operational energy. The labelling of the building envelopes was also verified, according to the simulation method specified by the Technical Quality Requirements for Energy Efficiency Levels of Residential Buildings (RTQ-R). The software programme used to calculate performance was EnergyPlus. The results indicated that adopting all retrofit measures yielded improvements in the life cycle for only one building, namely, a 15% reduction in energy consumption and a payback time of 10.4 years. Although these results are lower than those reported in some international studies, the analysis showed significant improvements in the operational stage of both buildings, in both labelling and energy consumption.

Investigation of the ratio of exergy consumption to energy consumption for building energy efficiency

ABSTRACTThe Ratio of Exergy consumption to Energy consumption (REXE) of the building is defined in the paper. The building life cycle REXELC provides a full understanding of high-quality energy consumption during the building life cycle. It is proposed as a new thermodynamic parameter to evaluate the building life cycle energy efficiency. It also can be applied as a simplified way to calculate the building life cycle exergy consumption. Five public buildings in China are taken as the study cases. The energy consumption, exergy consumption, and cost per construction area of the five cases are calculated to study the parameter REXELC. It is concluded that the building life cycle REXELC mainly depends on the energy consumption proportion and REXE of the building material’s production stage and building running stage. The economic analysis of the buildings shows that the building with too large or too small REXELC would not be the economic one. At last 2 mathematical regression models are established to investigate the relation between building life cycle energy consumption and REXELC. According to the regression model, all the buildings can be divided into four zones. The REXELC would be an important instruction in optimizing the design of building envelope.

Analysis on Life Cycle Energy Consumption and Emission of Vehicle Gas Produced by Kitchen Waste

Based on the life cycle analysis method, the life cycle analysis model of the energy consumption and emission of the vehicle gas which was produced by kitchen waste’s anaerobic fermentation was established. By calculating each phase of the life cycle energy consumption and emission of biomass vehicle gas, by contrastive analysis between the research result and the conventional diesel oil, this research concludes that using biomass vehicle gas produced by kitchen waste instead of using conventional diesel fuel in urban buses has a better energy conservation and emission reduction effect.

Lifecycle energy consumption and greenhouse gas emissions from corncob ethanol in China

AbstractConverting corncobs into fuel ethanol is different from converting stover because cobs have higher hemicellulose and lower lignin than stover. Current research provides life‐cycle assessments of greenhouse gas (GHG) emissions for stover ethanol but lacks such assessments for corncob ethanol. This study attempts to fill this gap by estimating the lifecycle energy consumption and carbon emissions for corncob ethanol using the GREET (Greenhouses gases, Regulated Emissions, and Energy use in Transportation) model. Our well‐to‐pump (WTP) estimate of fossil fuel consumption is 0.51–0.84 MJ MJ−1 of ethanol produced. The estimated GHG emissions are 39.44–49.97 gCO2eq/MJ of ethanol; about 90% is attributed to the conversion process. If glucose and xylose are co‐fermented, it requires 10% less energy and emits about 20% fewer GHGs from well to pump. The estimates are sensitive to the variations in corn yield and hydropower supply. Pump‐to‐wheel emissions are also assessed for representative vehicles with spark‐ignition engines in China. We find that hybrid and plug‐in hybrid electric vehicles have 18–20% lower emissions than internal combustion engine vehicles (ICEVs), and flexible‐fuel vehicles using E85 have similar WTP emissions to ICEVs. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd

A Comparison of the Life Cycle Energy Consumption and Emissions of BEV and HEV

There is an ongoing debate over whether battery electric vehicles (BEV) contribute to reducing energy consumption and emissions compared with hybrid electric vehicles (HEV). By following the theory of life cycle assessment (LCA), a calculation model for comparing the life cycle energy consumption and emissions of BEV and HEV is built. Typical BEV and HEV are selected as the empirical objects, whose main parameters of powertrain system (including engine, battery, motor, electric control, etc.) are obtained. By using VS and Mat Lab software programming, the life cycle differences of energy-consumption and emissions between BEV and HEV are calculated and analyzed. The results reveal that the HEV is more energy-saving and environmentally friendly than BEV. This result is mainly attributed to the increase of energy consumption of BEV due to high working intensity in assembly manufacturing process. At the same time, the manufacturing process of battery, as the core component of BEV, is not as mature as internal combustion engines, which leads to higher energy consumption and emissions.

Wireless charger deployment for an electric bus network: A multi-objective life cycle optimization

Deploying large-scale wireless charging infrastructure at bus stops to charge electric transit buses when loading and unloading passengers requires significant capital investment and brings environmental and energy burdens due to charger production and deployment. Optimal siting of wireless charging bus stops is key to reducing these burdens and enhancing the sustainability performance of a wireless charging bus fleet. This paper presents a novel multi-objective optimization model framework based on life cycle assessment (LCA) for siting wireless chargers in a multi-route electric bus system. Compared to previous studies, this multi-objective optimization framework evaluates not only the minimization of system-level costs, but also newly incorporates the objectives of minimizing life cycle greenhouse gas (GHG) emissions and energy consumption during the entire lifetime of a wireless charging bus system. The LCA-based optimization framework is more comprehensive than previous studies in that it encompasses not only the burdens associated with wireless charging infrastructure deployment, but also the benefits of electric bus battery downsizing and use-phase vehicle energy consumption reduction due to vehicle lightweighting, which are directly related to charger siting. The impact of charger siting at bus stops with different route utility and bus dwell time on battery life is also considered. To demonstrate the model application, the route information of the University of Michigan bus routes is used as a case study. Results from the baseline scenario show that the optimal siting strategies can help reduce life cycle costs, GHG, and energy by up to 13%, 8%, and 8%, respectively, compared to extreme cases of “no charger at any bus stop” and “chargers at every stop”. Further sensitivity analyses indicate that the optimization results are sensitive to the initial battery unit price ($/kWh), charging power rate (kW), charging infrastructure costs, and battery life estimation methods.

Life cycle energy consumption and greenhouse gas emissions of urban residential buildings in Guangzhou city

Abstract Carbon emissions are derived mainly from the building, industrial, and transport sectors. Buildings are responsible for more than 40% of global energy use and for as much as 33% of global greenhouse gas emissions. By the end of 2016, 57.4% of the total population lived in urban areas in China, a dramatic increase from 26% in 1990. It is essential to study and analyze both energy consumption and carbon emissions of buildings. Taking Guangzhou city of China as an example, this study applied a hybrid life cycle assessment approach to quantify both the energy consumption and CO2 emissions throughout the life cycle of an urban residential building. The data was collected from the Guangzhou input–output (IO) table of 2012, Guangzhou Statistical Yearbook of 2013, China Electric Power Yearbook of 2013, and statistical data of the studied building. Results showed that the overall life cycle energy consumption and CO2 (eq.) emissions for the studied building, constructed in 2012, were approximately 72,591.98 GJ and 12,637.32 t, respectively. The largest CO2 (eq.) emission factor was oil and the smallest one was electricity. The CO2 emissions of steel, concrete, brick, and cement together accounted for 76.69% of the total emissions which are related to building materials in the preparation stage. This research not only promotes the construction of eco-cities or eco-communities, but also provides decision makers with comprehensive data on the energy consumption and environmental impacts of residential buildings. The findings are of considerable importance in terms of energy saving and emissions reductions for society as a whole.

Environmental and economic impact of using new-generation wide-base tires

New-generation wide-base tire (NG-WBT) is known for improving fuel economy and at the same time for potentially causing a greater damage to pavement. No study has been conducted to evaluate the net environmental saving of the combined system of pavements and NG-WBT. This study adopted a holistic approach (life cycle assessment [LCA] and life cycle costing [LCC]) to quantitatively evaluate the environmental and economic impact of using NG-WBT. The net effect of different levels of market penetration of NG-WBT on energy consumption, global warming potential (GWP), and cost based on the fatigue cracking and rutting performance of two different asphalt concrete (AC) pavement structures was evaluated. The performance of pavements was determined based on pavement design lives; pavement surface characteristics, and pavement critical strain responses obtained from the artificial neural network (ANN) based on finite element (FE) simulations were used to calculate design lives of pavements. Based on the calculated design lives, life cycle inventory (LCI) and cost databases, and rolling resistance (RR) models previously developed by the University of Illinois at Urbana-Champaign (UIUC) were used to calculate the environmental and economic impact of the combined system. The fuel economy improvement using NG-WBT is 1.5% per axle. Scenario-based case studies were conducted. Considering 0% NG-WBT market penetration (or 100% standard dual tire assembly [DTA]) as a baseline, scenario 1 assumed the same fatigue and rutting potential between NG-WBT and DTA; therefore, the only difference came from fuel economy improvement of using NG-WBT. In scenario 2, pavement fatigue cracking potential determined the pavement design life; both thick and thin AC overlay sections experienced positive net environmental savings, but mixed net economic savings. In scenario 3, pavement rutting potential determined the pavement design life; the thick AC overlay section experienced positive net environmental savings, but mixed net economic savings. The thin section experienced negative net environmental and economic savings. The outcomes of scenario-based case studies indicated that NG-WBT can result in significant savings in life cycle energy consumption and cost, and GWP; however, these benefits were sensitive to the method used to determine the pavement performance; especially, a small change in pavement strain can result in significant change in pavement life. In addition, the effect of fuel price/economy improvement, discount rate, and International Roughness Index (IRI) threshold values was studied in the sensitivity analyses.

Impact of Wide-Base Tires on Pavements: A National Study

This paper summarizes a multi-year effort comparing the new-generation wide-base tires (NG-WBT) and dual-tire assembly from a holistic point of view. The tires were compared considering not only pavement damage but also environmental impact. Numerical modeling, prediction methods, experimental measurements, and life-cycle assessment were combined to provide recommendations about the use of NG-WBT. A finite element (FE) approach considering variables that are usually omitted in the conventional analysis of flexible pavement was used for modeling pavement structures combining layer thickness, material properties, tire load, tire-inflation pressure, and pavement type (interstate and low volume). A prediction tool, ICT-Wide, was developed based on an artificial neural network to obtain critical pavement responses in cases excluded from the FE analysis matrix. Based on the bottom-up fatigue cracking, permanent deformation, and international roughness index, the life-cycle energy consumption, cost, and green-house gas emissions were estimated. To make this research useful for state departments of transportation and practitioners, a modification to AASHTOware is proposed to account for NG-WBT. The revision is based on two adjustment factors, one accounting for the discrepancy between the AASHTOware approach and the FE model of this study, and the other addressing the impact of NG-WBT. Although greater pavement damage may result from NG-WBT, for the analyzed cases, the extra pavement damage may be outweighed by the environmental benefits when NG-WBT market penetration is considered.

Life cycle energy of high-rise office buildings in Hong Kong

Buildings are responsible for about 92% of the total energy end-use in Hong Kong, of which above 70% is from the commercial sector. Most of the buildings in Hong Kong are high-rise, and approximately 15% of the total building stock is commercial buildings. Despite the considerable improvement in the understanding of the life cycle energy use of office buildings, there is still a lack of research into the life cycle energy demand of high-rise office buildings. Such knowledge is however essential for facilitating building energy conservation in the high-rise urban environment. The aim of this paper is to investigate the life cycle energy use of high-rise office buildings. The research was carried out through a critical literature review and case studies of ten real-life high-rise office buildings in Hong Kong. Results show that the life cycle energy consumption is 51.78–73.64 GJ/m2 over the 50-year study period. Building operation consumes 78–89% and the rest (i.e. 11–22%) is taken by the embodied energy. Despite the distinction in terms of the amount of embodied energy between high-rise buildings and low-rise counterparts, no clear correlation is found between building height and embodied energy intensity. Moreover, energy use for material manufacturing and transport should be prioritised in reducing the embodied energy, of which the transport energy needs to be taken into extra consideration for the case of Hong Kong. The findings should inform construction industry participants of the significant potential in reducing the embodied energy of high-rise office buildings. The paper profiles the life cycle energy use of high-rise office buildings and should be important for the policy formulation towards the holistic energy conservation in high-rise buildings over their lifespans.

Energy Consumption and Carbon Emission Analysis of Natural Graphite Anode Material for Lithium Batteries

The production process of nature graphite anode material is divided into four stages, namely mining, beneficiation, purification and processing. Carbon emission and energy consumption during the whole process were quantified and analyzed in this study. The energy consumption and pollutant emissions in the production process were calculated in accordance with the method of life cycle assessment, and the carbon emission analysis was conducted by IPCC method. The life cycle energy consumption of 1 ton natural graphite anode material is 112.48GJ, and the processing stage contributes 41.71%. The results show that coke oven gas and raw coal are the main energy consumption in the whole life cycle of natural graphite anode material, which account for 32.33% and 23.41% of the total energy consumption, respectively. Furthermore, the carbon emission of 1 ton of natural graphite anode material is 5315.91kgCO2-eq, and mainly comes from raw coal and electricity which contribute 23.98% and 20.99% to the total carbon emission respectively, and CO2 is the largest carbon emission contributed 98.69% to total carbon emission. Finally, the carbon emissions are sensitive to the coke oven gas, raw coal, diesel and electricity, and insensitive to fuel oil.

Life cycle assessment of thin-wall ductile cast iron for automotive lightweighting applications

Use phase fuel consumption is responsible for the majority of an automobile's life cycle energy consumption and greenhouse gas (GHG) emissions. Lightweighting is an important strategy to reduce use phase fuel consumption and potentially reduce vehicle life cycle impacts. A popular lightweighting technique is material substitution, in which conventional materials (e.g., iron, steel) are replaced with lighter ones (e.g., aluminum, magnesium). Material substitution, however, often results in higher material production impacts. A life cycle approach is useful in evaluating these material tradeoffs and assessing the overall energy and emissions benefits of lightweighting technologies. Thin-wall ductile cast iron (TWDCI) is a lightweighting fabrication technology that can provide comparable weight reduction to aluminum while having better mechanical properties. This study develops a parametric life cycle model to assess the life cycle performance of TWDCI compared to conventional cast iron and cast aluminum in terms of energy (MJ) and GHGs (as carbon dioxide equivalents - kg CO2e). This model was applied to three lightweighting cases: a differential casing, an engine block, and replacement of all cast iron parts. Fuel reduction values (FRVs) are used to calculate change in fuel consumption due to lightweighting. A sensitivity analysis on these lightweighting cases is employed to determine the mass reduction required to achieve net life cycle benefits and to show the effect of alloy composition on life cycle energy and emissions. Lightweighting by 2% results in equal life cycle energy and GHGs for TWDCI and conventional cast iron while 37% lightweighting is required for TWDCI to equal cast aluminum impacts. The implications of powertrain resizing afforded by lightweighting are also explored.

Multiobjective optimization of asphalt pavement design and maintenance decisions based on sustainability principles and mechanistic-empirical pavement analysis

ABSTRACTHighway pavement as an important component of transport infrastructure has significant impacts on economy, society, and environment. The management of highway pavement has been traditionally focused on economy. In this study, the impacts of management decisions are examined in three dimensions, including life-cycle cost (LCC), energy consumption, and greenhouse gas (GHG) emissions. Quantitative models to predict the three dimensions are developed from mechanistic-empirical pavement analysis results. Two decision variables, pavement thickness and threshold roughness level for pavement resurfacing, are found to be significant in affecting the three dimensions. These two variables are subsequently used as decision variables in multiobjective optimization. The ranges of decisions that result in minimum LCC, energy consumption, and GHG emissions are identified through multiobjective optimization. Although the analysis is illustrated in the context of pavement design and management in Hong Kong, the analysis techniques and procedures can be easily applied in other regions.

Life Cycle Energy Analysis of Reclaimed Water Reuse Projects in Beijing.

To illustrate the benefits of water reuse project, the process-based life cycle analysis (LCA) could be combined with input-output LCA to evaluate the water reuse project. Energy is the only evaluation parameter used in this study. Life cycle assessment of all energy inputs (LCEA) is completed mainly by the life cycle inventory (LCI), taking into account the full life cycle including the construction, the operation, and the demolition phase of the project. Assessment of benefit from water reuse during the life cycle should focus on wastewater discharge reduction and water-saving benefits. The results of LCEA of Beijing water reuse project built in 2014 in a comprehensive way shows that the benefits obtained from the reclaimed water reuse far exceed the life cycle energy consumption. In this paper, the authors apply the LCEA model to estimate the benefits of reclaimed water reuse projects quantitatively.