Energy Embodied in Goods in International Trade of China: Calculation and Policy Implications

In recent years, China's energy demand and Greenhouse gas (GHG) emissions have grown very fast, quite an amount of which was exported as energy embodied in goods in international trade rather than consumed domestically. Starting from the concept of embodied energy, based on input-output energy analysis approach, in this paper the energy embodied in goods in international trade of China during the period from 2001 to 2006 is calculated. The results show that although China has become a net importer of petroleum since 1993, China is a net exporter of embodied energy due to international trade in goods. In 2002, the total amount of energy embodied in exported goods was about 410 million tce (ton of coal equivalent, hereinafter referred to as "tce"). Eliminating the amount of energy embodied in imported goods of about 170 million tce, the net export of embodied energy was about 240 million tce, accounting for 16% of the aggregate primary energy consumption of that very year in China, and the net export of embodied emissions was about 150 million tons of carbon. With the rapid growth of China's international trade, assuming no structural input-output changes of among sectors, in 2006 the net export of embodied energy went up to about 630 million tce, an increase of 162 % over 2002. In addition, this paper also analyzes the possible sources of error in calculation, and also discusses the policy implications according to the result of the calculation.

Creation of Zero CO₂Emissions Residential Buildings due to Operating and Embodied Energy Use on the Island of Crete, Greece

The possibility of creating zero CO2 emissions residential buildings due to life cycle energy use in the island of Crete, Greece has been examined. In a typical residential building located in Crete, Greece, its annual operating energy has been appraised at 170 KWh/m2 and its embodied energy at 30 KWh/m2. Various locally available renewable energies including solar energy, solid biomass and low enthalpy geothermal energy with heat pumps have been considered for generating the required heat and offsetting the grid electricity used. Their technologies are mature, reliable and cost-effective. Offset of the annual grid electricity use in the building with solar-PV electricity is allowed according to the net metering regulation. For zero carbon emissions due to embodied energy of the building, generation of additional solar electricity injected into the grid is required. A mathematical model has been developed for sizing the required solar-PV system installed in the building in order to offset the grid electricity use. For a residential building in Crete, Greece with a covered area of 100 m2, the power of the additional solar-PV system has been estimated at 1.6 KWp and its cost at 2400 €. In the current work, it is indicated that the creation of a zero CO2 emissions residential building due to life cycle energy use in Crete, Greece does not have major difficulties and it could be achieved relatively easily.

Influence of Choice of Structural System &In-Fill Masonry on the Embodied Energy &Cost of a Low-Rise Residential Urban-Building Indian Case Study

In the urban residential building stock, a major proportion is constituted by low-rise individual buildings. In addition to cost, quality and duration, energy consumed for the project needs to be accounted in the decision making process. Minimizing the cost of construction without compromising on the architectural and structural requirements is the primary objective of the residential buildings of stake-holders, especially the owners. The choice of structural system and the materials used for construction play a crucial role in this effort. This means that the use of expensive and/or voluminous materials such as cement, steel, masonry etc. is optimized. This could lead to significant reduction in embodied energy as well, if the choice of the structural system is prudently made. In this paper, an attempt has been made to quantify the cost and embodied energy benefits for a low-rise residential building by choosing two different structural systems, namely moment resisting framed (MRF) construction system and the partly load-bearing (PLB) system. The influence of choice of materials, contributing to reduction of cost and/or energy is discussed. It is clearly noticed that, when the structural system is re-configured as a PLB system from the existing MRF system there is significant reduction in cost and embodied energy without changing the architectural form.

Comparison of Embodied Energy/CO_(2)of Office Buildings in China and Japan

The embodied energy/CO2 of buildings in China and Japan, which reflects the characteristic industrial efficiency ofbui｜ding materials, is described in this paper. The energy consumption and CO2 intensities for the dominant materials used in buildings are derived from the energy consumption in factories, and the energy consumption to produce equipment is derived from IO （input/output） analysis in order to compare the embodied energy/CO2 for buildings between China and Japan based on the same estimation method. Although the energy consumption of structures in China is two to three times greater than in Japan, the interior finish and air conditioning equipment, for example, are simpler and smaller. As a result, the embodied energy/CO2 of office buildings in China is only 10% to 20% greater than that of Japanese office buildings. Thus, the embodied energy/CO2 of buildings depends on both industrial efficiencies and building design trends of the country.

Embodied coefficient of energy carriers and its calculation method

To quantify the energy consumption in the process of production, transportation and processing of energy carriers, the life cycle of building energy used can be divided into two phases： on-site phase and embodied phase. As for the embodied phase, with the data in existing statistic yearbook, the consumption items of energy production and transportation were investigated. And based on the life cycle theory, an embodied coefficient of energy carriers was proposed to quantify the embodied energy consumption. Moreover, a calculation method for the embodied coefficient of energy carriers was deduced using Leontief inverse matrix based on the existing data sources. With relevant data of 2005-2007 in China, the embodied coefficients in 2005-2007 were obtained, in which the values for natural gas and thermal power are around 1.3 and 3. l, respectively; while they are 1.03-1.08 for other selected energy carriers. In addition, it is also found that the consumption in the production and processing accounts for more than 75%.

Analysis of the Energy Embodied in Foreign Goods Trade of China

In recent years,scientists have been increasingly interested in the energy embodied in traded goods among countries.In this article,the direct energy intensities in various economic sectors of China were calculated with the data of energy consumption and output value of each sector,and the input-output table was used to estimate the external energy consumption.The total energy intensity of all sectors was then obtained.From the data of international trade,the energy embodied in goods trade of China was estimated for the period of 1994-2001.During this period,the average energy intensity of imported goods was always higher than that of exported ones.As a country with a surplus in international goods trade,China actually imported net embodied energy in the past few years.The net embodied energy imported was at the same magnitude of the imported energy in the form of fossil fuels.

Quantifying Embodied Energy Using Green Building Technologies under Affordable Housing Construction

The building construction industry is a major contributor of environmental pollution, with high levels of energy consumption and greenhouse gas emissions, all of which contribute to climate change. Housing is the single largest subsector of the construction industry. It is also a basic need associated with social and economic benefits, and its demand in most emerging economies is substantial. Hence it is a sector with significant potential not to mitigate just the negative impact of climate change on buildings and people, but also to reduce the impact of the construction industry on the natural environment. Green buildings technology has advanced greatly in recent years, but most “high performance” green buildings are capital intensive, often with high-tech applications that are not in easy reach of the mass housing market. In the developing country context, where huge segments of the population lack access to essential services or housing, the green buildings approach to addressing climate change is perceived to be largely unaffordable. For green technology to be adopted in poorer nations and have scalable impact, it will have to be low-cost and affordable. According to a 2010 report, buildings in the commercial, office and hospitality sectors are poised to grow at 8% annually over the next 10 years in India. While the retail sector has been growing rapidly at 8% per annum, the residential sector has seen growth of 5% per annum during this period. It is estimated that over 70 million New Urban Housing Units will be required over the next 20 Years.

Evaluating the LCA of a Building with Close Embodied Energy Which Has Different Functions

Annual energy consumption and annual Global Warming Potential （GWP） decreases with the improving of the energy performance of the facade, whereas the embodied energy and embodied GWP increases due to the extra material and products applied. This study analyses the relation between the embodied energy and the energy consumption of a house during the life span of the buildings, and the results represented separately in tables and figures. The study uses Life Cycle Assessment （LCA） framework as a tool to conduct a partial LCA, from cradle to site of the construction and energy consumption during usage phase of the buildings with three different wall types through 50 years usage phase. According to this study, laminated timber and aerated concrete are better choices than cast concrete for both types of buildings because of lower density and lower U value.

Embodied Energy &Cost Issues of Tank-Bed-Lime Based Geopolymer Adobes

It is well-known that a product or a system is sustainable if it is economically viable, socially acceptable and environmentally friendly. Load bearing masonry is one such example which is quite sustainable, especially if the masonry units are locally available. It is important to quantify the environmental benefits and cost, if an alternative to an existing technology is to be suggested. Of course the issues related to acceptance have to be discussed and addressed. This paper presents the quantification of embodied energy and cost of lime-pozzolana-cement (LPC) geopolymer based masonry units made using locally available bulk ingredients viz. tank-bed soil (TBS) and brick-powder (BP). The masonry adobe units developed have achieved the target performance in terms of strength, low water absorption and relative ease of production. Simultaneously the issues related to cost are also discussed in this paper. The studies have revealed that the bulk contributor to embodied energy and cost of geopolymer adobes are the alkaline materials viz sodium hydroxide and sodium silicate. However, the embodied energy and cost per unit strength appears to be better than that of conventional table moulded bricks in south India, especially when alkaline solution at 2M concentration is used with LPC.

Impact of Different Parameters on Life Cycle Analysis, Embodied Energy and Environmental Emissions for Wind Turbine System

Due to the rapid depletion of fossil fuel reserves and increasing concern for climate change as a result of greenhouse gas effect, every country is looking for ways to develop eco-friendly renewable energy sources. Wind energy has become a good option due to its comparative economic advantages and environment friendly aspects. But there is always an ongoing debate if wind energy is as green as it seems to appear. Wind turbines once installed do not produce any greenhouse gases during operation, but it can and may produce significant emissions during manufacture, transport, installation and disposal stages. To determine the exact amount of emissions, it is necessary to consider all the stages for a wind turbine from manufacture to disposal. Life Cycle Analysis (LCA) is a technique that determines the energy consumption, emission of greenhouse gases and other environmental impacts of a product or system throughout the life cycle stages. The various approaches that have been used in the literature for the LCA of wind turbines have many discrepancies among the results, the main reason(s) being different investigators used different parameters and boundary conditions, and thus comparisons are difficult. In this paper, the influence of different parameters such as turbine size, technology (geared or gearbox less), recycling, medium of transport, different locations, orientation of the blade (horizontal or vertical), blade material, positioning of wind turbine (land, coastal or offshore), etc. on greenhouse gas emissions and embodied energy is studied using the available data from exhaustive search of literature. This provides tools to find better solutions for power production in an environmental friendly manner by selecting a proper blade orientation technique, with suitable blade material, technology, recycling techniques and suitable location.

Evaluation of Embodied Energy and Construction Costs for the Design of Low-Rise Apartments for Low-Income Residents in Surabaya, Indonesia

Low-rise apartments for low-income residents have been built in Surabaya in recent years. They have four stories and many rooms, and the dwellers are all small traders. Because these projects are built with funds from the government, the buildings are designed to consider the cost of construction, without consideration of embodied energy material. As a result, the buildings are not optimal in terms of embodied energy and construction cost. At present, because there are both concerns over global warning and a worldwide energy crisis, the embodied energy in a building is a very important concept for building design, because it can determine usage of energy in relation to natural sources, especially fossil fuels. This is part of the sustainable design concept. This paper describes research regarding： differences in embodied energy and construction cost between different wall materials, including brick, corn block and lightweight concrete in low rise apartments; the optimal relationship between embodied energy and building cost; and which factors determine these differences. The findings of this research show that lightweight concrete is the best material for the building walls; apartments for low-income in Surabaya still do not represent optimal construction design; and that sustainable buildings are cheaper than those that do not use this concept.

Embodied Energy and CO2 Associated with Buildings by Using Input and Output Table in Japan

In July 2009, the 2005 basic Japanese input/output table was publicized together with its physical transaction table. This research paper analyzed the 2005 IO （input/output） table to create building industry-related intensities and, at the same time, compared the building industry with industries at large for distribution margins and transportation. The analysis of distribution margins separately for middle and purchaser margins found that middle margins in the building industry are minor at 35% of the averages for all industries, while purchaser margins are sizable at 1.8 times, proving that it is an industry for which local production for local consumption is quite effective. CO2 emissions resulting from transportation in the building industry were calculated and concisely characterized. Although the ratio of transportation CO2 emissions to total CO2 emissions in each industry finds almost no difference between general industries and the building industry, transportation CO2 emissions per production value are two to three times heavier than those from general industries to be justified as a transportation-intensive industry.

Intensity Calculation Using Input-Output Table and Case Study Regarding Embodied Energy/CO2 in Japan

The objective of this research is to quantify the EEC （embodied energy/CO2） of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building＇s life-cycle, such as construction （including manufacture of materials and equipment）, renewal （including repair work） and demolition. Energy and CO2 emission intensities in terms of 401 sectors were calculated, using the 2005 I-O （input-output） table in Japan. According to our case study conducted from the construction phase to demolition, the EC （embodied CO2） of an office building used for 60 years is 12,044 t-CO2 and 1,093 kg-CO2/m^2 in total. CO2 equivalent emissions （CO2e） by Freon gases, contained in building materials, equipment and devices, were also calculated. As the results, CO2e by insulators was 2% of the building＇s EC and CO2e by refrigerants was 9%-12% of the building＇s EC. It is important to keep reducing emissions of Freon gases contained in refrigerators.

Study on Impact of Embodied Energy and CO2 Emissions for Prolongation of Building Life Time： Case Study in Japan

In this study, we looked at a method quantifying EEC （embodied energy and CO2） and the effect when we prolonged the building life time particularly through the durable improvement of the structure. Increasing the covering thickness of concrete for reinforcing bars and the earthquake-resistant strength are methods to increase the durability of the structure. The calculation method to obtain the quantity of concrete and reinforcing bars is provided. The EEC increase is evaluated from the 2005 input-output table in Japan. These results show that EE （embodied energy） in the construction phase is increased by 11% to 20% and EC （embodied CO2） 17% to 32%. However, annual EE is reduced 66% to 72% and EC 70% to 79%,

ENERGY EMBODIED IN,AND TRANSMITTED THROUGH,WALLS OF DIFFERENT TYPES WHEN ACCOUNTING FOR THE DYNAMIC EFFECTS OF THERMAL MASS

Embodied energy is a measure of the energy used in producing,transporting and assembling the materials for a building.Operational energy is the energy used to moderate the indoor environment to make it functional or comfortable-primarily,to heat or cool the building.For many building geometries,the walls make the most significant contribution to the embodied energy of the building,and they are also the path of greatest heat loss or gain through the fabric,as they often have a greater surface area than the roof or floor.Adding insulation reduces the heat flow through the wall,reducing the energy used during operation,but this adds to the embodied energy.The operational energy is not only a function of the wall buildup,but also depends on the climate,occupancy pattern,and heating strategy,making an optimisation for minimum overall energy use non-trivial.This study presents a comparison of typical wall construction types and heating strategies in a temperate maritime climate.The transient energy ratio method is a means to abstract the heat flow through the walls(operational energy for heating),allowing assessment of the influence of walls in isolation(i.e.in a general sense,without being restricted to particular building geometries).Three retrofit scenarios for a solid wall are considered.At very low U-values,overall energy use can increase as the embodied energy can exceed the operational energy;current best practice walls coupled with low building lifetimes mean that this point may be reached in the near future.Substantial uncertainty is present in existing embodied energy data,and given its contribution to total energy use,this is a topic of urgent concern.

完全隐含能源与碳强度研究进展综述

节能减排是应对全球气候变暖的重要举措。由于不同国家和地区的经济发展水平存在明显差异,近年来能源与碳强度成为度量节能减排绩效的重要指标,受到了社会各界的广泛关注。在生产端强度控制的基础上,如何从根源上在消费端降低完全隐含能源与碳强度的研究越来越受到重视。针对消费端完全隐含能源与碳强度的研究特征与发展趋势展开综述,结果发现:(1)主要呈现出国家层面研究为主、全球层面研究显著增加、省市层面研究开始出现的特征,且国家或省市层面主要聚焦于中国;(2)相比完全隐含能源强度,现有文献更为关注完全隐含碳强度;(3)研究由不区分终端消费向细分各终端消费发展,隐含在出口中的完全隐含碳强度受到了重点讨论;(4)部分研究侧重于局部,比如深度参与到全球生产网络的部分经济部门或能源消费与碳排放在生产网络中传输的关键层级;(5)进行完全隐含碳强度变动的驱动因素的研究主要基于乘性结构分解分析模型,从时间轴和空间轴展开剖析。现有研究框架未来可以扩展到能源环境相关领域的其他指标。

考虑环境影响的管道输送场站系统用能评价分析模型及应用

用能评价分析方法对系统节能减排和“双碳”目标实现具有指导作用,实际用能分析除了需要考虑能量分析外,还需要考虑污染物及温室气体排放等影响;基于能量利用和环境效应(污染物和温室气体排放等),构建新的用能评价分析模型,提出温室气体排放过程的虚拟能计算方法;利用所建模型对原油输送场站典型工艺系统进行用能分析,考虑输入及输出过程虚拟能对运行效率的影响。结果表明,考虑环境效应的用能分析,系统及设备(单元)虚拟效率均有所降低。

中国能源生态足迹空间差异及收敛趋势

文章基于隐含碳视角,采用净初级生产力模型测度1997-2021年全中国和各区域的能源生态足迹,运用核密度估计模型分析其动态分布特征,刻画空间绝对差异演变规律,进一步构建空间绝对β收敛和空间条件β收敛模型探究能源生态足迹的空间收敛性。研究结果表明:(1)中国能源生态足迹呈现稳定增加趋势,空间分布呈现“沿海高、内陆低”的分异性特征。(2)中国能源生态足迹总体分布呈现“单峰向多峰过度、主波峰左移”趋势,除了黄河中游和长江中游地区的能源生态足迹呈现“单峰”态势之外,其他地区的能源生态足迹均呈现“单峰向双峰转变”、“主波峰高度下降”、“右拖尾”的特征,区域间差异呈扩张趋势。从2003年开始两级分化现象加强,区域中两级分化最严重的是北部沿海和南部沿海地区,东北地区、西南地区和西北地区两级分化最弱。(3)区域的能源生态足迹均存在空间绝对和条件β收敛趋势且空间条件收敛速度快于空间绝对收敛速度,收敛速度最快的地区是东北地区,最慢的是长江中游地区。

生产网络视角下的碳税制度

本文从生产网络视角,探究对能源消费部门征收碳税如何通过生产网络联动影响各部门生产投入、产出及碳排放。由于生产网络的存在,征收碳税不仅会通过减少征税部门产出降低经济体总碳排放,还会通过生产网络上下游关联引发间接影响。因此,基于部门在生产网络中所处位置有针对性地征收碳税才能实现最大的减排效果。本文构建生产网络视角下的碳税模型,结合2020年中国投入产出表与估算的42部门、153部门碳排放数据,模拟分析征收小额碳税对征税部门劳动投入、产量、碳排放以及经济体总碳排放的影响。结果表明,对各部门征收碳税引发的减排效果与部门直接排放量的排序并非一一对应;对42部门中“石油、炼焦产品和核燃料加工品”“电力、热力的生产和供应”“金属冶炼和压延加工品”征税带来的减碳效果最明显,尤其是“石油、炼焦产品和核燃料加工品”部门,其碳税减排效应和碳减排效率均位于42部门中的首位,因此在制定碳税政策时可予以重点考虑。

双碳背景下建筑保温材料优选路径研究

建筑领域碳排放问题日益引起社会关注,建筑保温材料被认为是实现低碳建筑和节能减排目标的关键手段。然而在当前的建筑保温材料选择过程中,存在经济角度权重过高、忽视材料的隐含碳和气候影响等问题。针对不同地区建筑环境和气候的差异,通过研究建筑保温材料的性能和效益两个关键方面,旨在获得建筑保温材料的优选路径,研究成果对于促进低碳建筑建设和节能减碳的实施具有重要的参考价值。