Energy-related activities are a major contributor of greenhouse gas (GHG) emissions. A growing body of knowledge clearly depicts the links between human activities and climate change. Over the last century the burning of fossil fuels such as coal and oil and other human activities has released carbon dioxide (CO2) emissions and other heat-trapping GHG emissions into the atmosphere and thus increased the concentration of atmospheric CO2 emissions. The main human activities that emit CO2 emissions are (1) the combustion of fossil fuels to generate electricity, accounting for about 37% of total U.S. CO2 emissions and 31% of total U.S. GHG emissions in 2013, (2) the combustion of fossil fuels such as gasoline and diesel to transport people and goods, accounting for about 31% of total U.S. CO2 emissions and 26% of total U.S. GHG emissions in 2013, and (3) industrial processes such as the production and consumption of minerals and chemicals, accounting for about 15% of total U.S. CO2 emissions and 12% of total ...

The potential challenge for the effective GHG emissions mitigation of urban energy consumption: A case study of Macau

Greenhouse gas (GHG) emission and energy consumption were estimated in wastewater treatment plants using an elaborate mathematical model that included coagulation/flocculation, anaerobic digester, nitrification/denitrification, and biogas recovery. The examined treatment systems used aerobic, anaerobic, and hybrid biological processes. The impact of pertinent operating parameters including reactor temperature, solid retention time (SRT), primary clarifier underflow rate, and biochemical oxygen demand concentration on GHG emission and energy consumption were investigated, leading to the identification of controlling operating parameters and adequate strategies to reduce GHG emission and energy consumption. The overall GHG emission was 3152, 6051, and 6541 kg CO2‐equivalent/day, while the estimated energy consumption amounted to 4028, 2017, and 3084 MJ/day in the three examined systems, respectively. Parametric studies showed that the best strategy to reduce GHG emission and energy consumption would result from 12% increase in the bioreactor temperature in the aerobic system, 10% increase of the bioreactor temperature and five days increase of SRT in the anaerobic system, and 10% increase of temperature and five days reduction of SRT in the anaerobic bioreactor of the hybrid system. Additional reductions in the GHG emission and energy consumption would result from 50% increase of the primary clarifier underflow rate.

Energy consumption and the concomitant Green House Gases (GHG) emissions of network infrastructures are becoming major issues in the Information and Communication Society (ICS). Current optical network infrastructures (routers, switches, line cards, signal regenerators, optical amplifiers, etc.) have reached huge bandwidth capacity but the development has not been compensated adequately as for their energy consumption. Renewable energy sources (e.g. solar, wind, tide, etc.) are emerging as a promising solution both to achieve drastically reduction in GHG emissions and to cope with the growing power requirements of network infrastructures. The main contribution of this paper is the formulation and the comparison of several energy-aware static routing and wavelength assignment (RWA) strategies for wavelength division multiplexed (WDM) networks where optical devices can be powered either by renewable or legacy energy sources. The objectives of such formulations are the minimization of either the GHG emissions or the overall network power consumption. The solutions of all these formulations, based on integer linear programming (ILP), have been observed to obtain a complete perspective and estimate a lower bound for the energy consumption and the GHG emissions attainable through any feasible dynamic energy-aware RWA strategy and hence can be considered as a reference for evaluating optimal energy consumption and GHG emissions within the RWA context. Optimal results of the ILP formulations show remarkable savings both on the overall power consumption and on the GHG emissions with just 25% of green energy sources. © 2011 IEEE.

Magnesium is a promising lightweight and green metallic engineering material, but the environmental impact of primary magnesium production stage, especially greenhouse gas (GHG) emissions cannot be ignored. In this study, the life cycle energy consumption and GHG emissions caused by the production of primary magnesium in the years of 2003-2013 in China were calculated; the factor decomposition was conducted to analyze the GHG emissions of magnesium production process by using logarithmic mean Divisia index method (LMDI), including energy GHG emission factors, energy structure, energy consumption per ton of primary magnesium, production, emissions per unit of dolomite and ferrosilicon, and dolomite and ferrosilicon consumptions per ton of primary magnesium. The results showed that GHG emissions of primary magnesium production increased 260.29*104 t CO2eq in total from 2003 to 2013. The variety magnesium production contributed the biggest part of GHG emissions, accounting for 418.17%. The energy structure took second place on the contribution of GHG emissions, accounting for-161.49%. The nest part was energy consumption per ton of primary magnesium, accounting for-138.97%. While, the contribution of energy GHG emission factors, emissions per unit of dolomite and ferrosilicon, and dolomite and ferrosilicon consumptions per ton of primary magnesium was relatively small, which were 0.88%, 0.00% -2.72% -4.73% and-11.13%, respectively. Thus, it is the key methods to reduce GHG emissions by optimizing the energy structure and decreasing the energy consumption.

Post-occupancy Energy Consumption of BASIX Affected Dwellings in the Sydney Metropolitan Area

The sector with the higher weight in final energy consumption is the transport sector, reflecting the one responsible for most greenhouse gas (GHG) emissions. In this context, and given the increasing penetration of zero or low GHG emissions vehicles with high energy efficiency, this work intends to contribute to the future identification of the impact of the transport sector on energy consumption and resulting emissions. It aims at identifying the energy consumption in the sector and quantify the GHG levels from the comparative analysis of the increase of electric based vehicle fleet in detriment of those based in internal combustion engines, considering five scenarios until the year 2030. The study is applied in mainland Portugal considering the fleet of light passenger and commercial vehicles, which comprise the vast majority of the Portuguese fleet. The Bottom-up model, where the hierarchical tree detailing is constructed from detail to the whole, is applied to the study to determine the energy consumption and GHG emissions variables. The analysis is performed through the application of the simulation tool Long-range Energy Alternatives Planning system (LEAP) of scenario-based and integrated modelling, herein utilized to determine energy consumption and account for GHG emission sources. Results show that the increase of electric vehicles directly influences the reduction of GHG emissions and final energy consumption while electric energy consumption increases.

Based on the localized data of environmental load, this study has establishedthe life cycle assessment (LCA) model of battery electric passenger vehicle(BEPV) that be produced and used in China, and has evaluated the energyconsumption and greenhouse gases (GHGs) emission during vehicle pro-duction and operation. The results show that the total energy consumptionand GHG emissions are 438GJ and 37,100kg (in terms of CO2 equivalent)respectively. The share of GHG emissions in total emissions at the productionstage is 24.6%, and 75.4% GHG emissions are contributed by the operationalstage. The main source of energy consumption and GHG emissions at vehicleproduction stage is the extraction and processing of raw materials. TheGHG emissions of raw materials production accounts for 75.0% in the GHGemissions of vehicle production and 18.0% in the GHG emissions of fulllife cycle. The scenario analysis shows that the application of recyclablematerials, power grid GHG emission rates and vehicle energy consumption rates have significant influence on the carbon emissions in the life cycle ofvehicle. Replacing primary metals with recycled metals can reduce GHGemissions of vehicle production by about 7.3%, and total GHG emissionscan be reduced by about 1.8%. For every 1% decrease in GHG emissionsper unit of electricity, the GHG emissions of operation stage will decrease byabout 0.9%; for every 1.0% decrease in vehicle energy consumption rate, thetotal GHG emissions decrease by about 0.8%. Therefore, developing cleanenergy, reducing the proportion of coal power, optimizing the productionof raw materials and increasing the application of recyclable materials areeffective ways to improve the environmental performance of BEPV.

Aluminum production is a major energy consumer and important source of greenhouse gas (GHG) emissions globally. Estimation of the energy consumption and GHG emissions caused by aluminum production in China has attracted widespread attention because China produces more than half of the global aluminum. This paper conducted life cycle (LC) energy consumption and GHG emissions analysis of primary and recycled aluminum in China for the year 2020, considering the provincial differences on both the scale of self-generated electricity consumed in primary aluminum production and the generation source of grid electricity. Potentials for energy saving and GHG emissions reductions were also investigated. The results indicate that there are 157,207 MJ of primary fossil energy (PE) consumption and 15,947 kg CO2-eq of GHG emissions per ton of primary aluminum ingot production in China, with the LC GHG emissions as high as 1.5–3.5 times that of developed economies. The LC PE consumption and GHG emissions of recycled aluminum are very low, only 7.5% and 5.3% that of primary aluminum, respectively. Provincial-level results indicate that the LC PE and GHG emissions intensities of primary aluminum in the main production areas are generally higher while those of recycled aluminum are lower in the main production areas. LC PE consumption and GHG emissions can be significantly reduced by decreasing electricity consumption, self-generated electricity management, low-carbon grid electricity development, and industrial relocation. Based on this study, policy suggestions for China’s aluminum industry are proposed. Recycled aluminum industry development, restriction of self-generated electricity, low-carbon electricity utilization, and industrial relocation should be promoted as they are highly helpful for reducing the LC PE consumption and GHG emissions of the aluminum industry. In addition, it is recommended that the central government considers the differences among provinces when designing and implementing policies.

In this paper, we used the life-cycle analysis (LCA) method to evaluate the energy consumption and greenhouse gas (GHG) emissions of natural gas (NG) distributed generation (DG) projects in China. We took the China Resources Snow Breweries (CRSB) NG DG project in Sichuan province of China as a base scenario and compared its life cycle energy consumption and GHG emissions performance against five further scenarios. We found the CRSB DG project (all energy input is NG) can reduce GHG emissions by 22%, but increase energy consumption by 12% relative to the scenario, using coal combined with grid electricity as an energy input. The LCA also indicated that the CRSB project can save 24% of energy and reduce GHG emissions by 48% relative to the all-coal scenario. The studied NG-based DG project presents major GHG emissions reduction advantages over the traditional centralized energy system. Moreover, this reduction of energy consumption and GHG emissions can be expanded if the extra electricity from the DG project can be supplied to the public grid. The action of combining renewable energy into the NG DG system can also strengthen the dual merit of energy conservation and GHG emissions reduction. The marginal CO2 abatement cost of the studied project is about 51 USD/ton CO2 equivalent, which is relatively low. Policymakers are recommended to support NG DG technology development and application in China and globally to boost NG utilization and control GHG emissions.

Life cycle assessment of the energy consumption and GHG emissions of state-of-the-art automotive battery cell production

Impacts of green certification programs on energy consumption and GHG emissions in buildings: A spatial regression approach

With the increasingly prominent environmental problems and the decline of fossil fuel reserves, the reduction of energy consumption (EC) has become a common goal in the world. Urea industry is a typical energy-intensive chemical industry. However, studies just focus on the breakthrough of specific production technology or only consider the EC in the production stage. This results in a lack of evaluations of the life cycle of energy consumption (LcEC). In order to provide a systematic, scientific, and practical theoretical basis for the industrial upgrading and the energy transformation, LcEC of urea production and the greenhouse gas (GHG) emissions generated in the process of EC are studied in this paper. The results show that the average LcEC is about 30.1 GJ/t urea. The EC of the materials preparation stage, synthesis stage, and waste-treatment stage (ECRMP, ECPP, ECWD) is about 0.388 GJ/t urea, 24.8 GJ/t urea, and 4.92 GJ/t urea, accounting for 1.3%, 82.4%, and 16.3% of LcEC, respectively. Thus, the synthesis stage is a dominant energy-consumer, in which 15.4 GJ/t urea of energy, accounting for 62.0% of ECpp, supports steam consumption. According to the energy distribution analysis, it can be concluded that coal presents the primary energy in the process of urea production, which supports 94.4% of LcEC. The proportion of coal consumption is significantly higher than that of the average of 59% in China. Besides, the GHG emissions in the synthesis stage are obviously larger than that in the other stage, with an average of 2.18 t eq.CO2/t urea, accounting for 81.3% of the life cycle of GHG (LcGHG) emissions. In detail, CO2 is the dominant factor accounting for 90.0% of LcGHG emissions, followed by CH4, while N2O is negligible. Coal is the primary source of CO2 emissions. The severe high proportion of coal consumption in the life cycle of urea production is responsible for this high CO2 content of GHG emissions. Therefore, for industrial urea upgrading and energy transformation, reducing coal consumption will still be an important task for energy structure transformation. At the same time, the reformation of synthesis technologies, especially for steam energy-consuming technology, will mainly reduce the EC of the urea industry. Furthermore, the application of green energy will be conducive to a win-win situation for both economic and environmental benefits.

Major US electric utility climate pledges have the potential to collectively reduce power sector emissions by one-third

An integrated analytical framework for quantifying the LCOE of waste-to-energy facilities for a range of greenhouse gas emissions policy and technical factors