Towards a common carbon footprint assessment methodology for the water sector

This paper describes the carbon footprint methodology used in assessing the global warming potential of the Dutch water sector. The assessment includes CO₂ emissions from energy consumption and methane and nitrous oxide emissions from water treatment processes. There is, however, debate on the amounts and mechanism of greenhouse gas (GHG) emissions, and a standardised approach is discussed. As a result of this approach, the contribution of GHG emissions to the total carbon footprint of the Dutch water sector appeared to be relatively high. Next to the lack of common emission factors for GHG and chemicals used, there is also no agreed‐upon approach related to the system boundaries and scope of carbon footprinting of the water cycle. For reasons of benchmarking and monitoring of climate change reduction targets, a common carbon footprint assessment methodology for the water sector will be required.     

Cost effective energy and carbon emissions optimization in building renovation (Annex 56)

The construction sector has become an important target for reducing carbon emissions and energy consumption and for kerbing resource depletion, because of its relevance in all these important areas.Many of the current energy related policies have their focus on new buildings but, due to the low rates of replacement of the existing building stock, it is crucial that the low energy performances of these buildings are improved. Most of these buildings,due to design and construction constraints,may not be able to reach the new energy efficiency standards,which many times involve complex construction works. Nevertheless, the achievement of significant reductions in energy consumption and carbon emissions may not always require a highly efficient solution for the envelope. Other solutions, combining energy efficiency measures and the use of renewable energy, are also possible.In this context, the key research problem addressed in Annex 56 was to understand how far it is possible to go with energy conservation and efficiency measures and from which point the measures to foster renewable energy use become more economical taking into account the local context and the many restrictions the existing buildings face.Thus,a new methodology was developed to be used in the decision making process for energy related building renovation, allowing to find a cost-effective balance between energy consumption,carbon emissions and overall added value achieved in the renovation process.The methodology developed within IEA EBC Annex 56 project aims at defining,assessing and comparing energy renovation activities in a cost-effective way,o ptimizing the energy use and the carbon emissions reduction,mainly in residential buildings but also in non-residential buildings without complex HVAC technologies.The methodology explores the full range of cost-effective reduction of carbon emissions and energy use and takes into account also the additional benefits and the overall added value achieved by the building within the renovation process.     

建筑给排水专业节能措施及再生水资源的利用

结合国家节能减排目标和保护环境战略,从给排水专业角度阐述了具体的节能减排措施,包括采用管网叠压供水设备、太阳能,做好保温措施等,并对污废水及雨水的再生利用进行了探讨,以期指导实践,从而科学有效地节能减排。     

Benchmarking energy consumption and CO2 emissions from rainwater‐harvesting systems: an improved method by proxy

Life cycle analyses (LCAs) show the main operational energy contribution for rainwater‐harvesting (RWH) systems come from ultraviolet (UV) disinfection and pumping rainwater from tank to building. Simple methods of estimating pump energy consumption do not differentiate between pump start‐up and pump‐operating energy or include pump efficiency parameters. This paper outlines an improved method incorporating these parameters that indirectly estimates pump energy consumption and carbon dioxide (CO₂) emissions using system performance data. The improved method is applied to data from an office‐based RWH system. Comparison of the simple and improved methods identified the former underestimates pump energy consumption and carbon emissions by 60%. Results of the improved method corresponded well to directly measured energy consumption and energy consumption represented 0.07% of an office building's total energy consumption. Consequently, the overall energy consumption associated with RWH systems is a very minor fraction of total building energy consumption.     

分布式能源利用的经济性与环境影响研究——基于DER-CAM模型

分布式供能系统是一种先进的供能系统,具有高效、环保、经济等特点,在降低建筑能耗方面潜力巨大。采用DER-CAM模型模拟我国不同气候区的商业建筑分布式能源的经济性与环境影响,得到多技术集成优化能有效减排降本、政策引导与经济刺激会促进分布式能源技术应用等启示,为我国能源合理规划、适宜技术选择以及提升能源效率及经济性提供参考。     

Evaluation of fuel-switching opportunities in the residential sector

The aim of this paper is to analyse the impact of different natural gas and electricity end-use technologies in the residential sector, which compete among themselves in terms of energy consumption and carbon emissions. The analysis of 17 different technology options, which were chosen in order to match the consumption behaviour of a typical Portuguese family, has shown that the use of electric heat pumps, both for space and water-heating, combined with the use of a natural gas cooker, leads to the lowest energy consumption and to the lowest environmental impacts in terms of carbon emissions. Considering only the running costs, this choice is 45% more economic than having a natural gas centralised heating system combined with a gas cooker, and is 60% more economic than having an electric resistance space heater combined with an electric storage water heater and electric cooker, which is the worst case. The life cycle cost (LCC) analysis shows that the economic optimum is reached by the combination of a natural gas water heater with an electric storage space heater, and a natural gas cooker. The cost of conserved carbon (CCC) analysis shows that the combination of an electric heat pump water heater with an electric storage space heater, and a natural gas cooker is the best option in terms of environmental performance.     

Occupants have little influence on the overall energy consumption in district heated apartment buildings

The purpose of this research is twofold: first, to evaluate how occupant behavior in a neutral environment influences the overall greenhouse gas emissions and energy consumption of multi-family apartment buildings, and second: to establish which activities associated with housing companies produce the most greenhouse gas emissions. The research comprised of a multiple cases of housing companies dating from the late 1960s and located in the Finnish capital Helsinki. The studied housing companies represent the least energy efficient third of the Finnish residential building stock, approaching obligatory large scale refurbishments. The analysis is conducted in two phases with a so called hybrid life-cycle assessment (LCA) technique. Using the technique, both economic and metric consumption data are analyzed to estimate the greenhouse gas emissions generated by activities associated with housing. In line with previous research, the study identifies heating energy as the single most significant contributor to greenhouse gas emissions. The results also show that the carbon load associated with housing activities makes up one third of an individual resident's overall carbon footprint. Contrary to often stated belief, the study indicates that occupant behavior has only limited effect on the energy consumption and, consequently, carbon emissions derived from housing, particularly when multi-family housing connected to district heating is concerned. However, apartment size seems to have a two-way impact, the smallest and the largest being the least energy efficient.     

Analysis and optimization of CCHP systems based on energy, economical, and environmental considerations

Analysis of combined cooling, heating, and power (CCHP) systems is frequently based on reduction of operating cost without measuring the actual energy use and emissions reduction. CCHP systems can be optimized based on different optimization criterion such as: energy savings, operation cost reduction or minimum environmental impact. In this study, CCHP systems operated following the electric load (FEL) and the thermal load (FTL) strategies are evaluated and optimized based on: primary energy consumption (PEC), operation cost, and carbon dioxide emissions (CDE). This study also includes the analysis and evaluation of an optimized operational strategy in which a CCHP system follows a hybrid electric-thermal load (HETS) during its operation. Results show that CCHP systems operating using any of the optimization criteria have better performance than CCHP systems operating without any optimization criteria. For the evaluated city, the optimum PEC and cost reduction are 7.5% and 4.4%, respectively, for CCHP-FTL, while the optimum CDE reduction is 14.8% for CCHP-FEL. Results also show that the HETS is a good alternative for CCHP systems operation since it gives good reduction of PEC, cost, and CDE. This optimized operation strategy provides a good balance among all the variables considered in this paper.     

Quantifying the potential impacts of China's power-sector policies on coal input and CO2 emissions through 2050: A bottom-up perspective

This study evaluates four recent policies for China's power sector—mandatory renewable targets, green dispatch, carbon capture and sequestration development, and coal-fired generation efficiency improvements—and quantifies their energy and carbon dioxide (CO₂) emissions reduction potential through 2050 using bottom-up energy modeling and scenario analysis. We find renewable targets and green dispatch have crucial interlinked impacts on energy and CO₂ emissions that could change the shape and peak year of China's power-sector emissions outlook. Without either renewable targets or green dispatch, coal will likely continue dominating China's power mix and could delay the power-sector CO₂ emissions peak to the late 2030s.     

Energy performance and indoor environmental quality in Hellenic schools

School buildings constitute a major part of the non-residential building stock, though due to their operational characteristics, they represent a low percentage of the overall energy balance of the building sector. Although health and productivity of pupils and teachers is strongly affected by the indoor environmental quality of their school, poor indoor air quality has been reported in published literature, even so for recently constructed school buildings. The same applies for the energy consumption, with large amounts of energy being wasted because no energy saving measures are applied for the operation of schools. This paper presents the outcome of a study on the energy performance of Hellenic school buildings. The general features of the contemporary building stock are presented along with the results from an energy survey in 135 Hellenic schools. The derived energy consumption benchmarks are compared with published literature. Finally, the energy performance and indoor environmental quality of a representative sample of schools in metropolitan Athens are assessed in a holistic approach to the “energy efficiency – thermal comfort – indoor air quality” dilemma. The IEQ assessment was based on an objective evaluation by monitoring crucial indoor conditions and a subjective occupant evaluation using standardized questionnaires. The potential of several energy conservation measures is evaluated in terms of energy savings and reduction of greenhouse gas emissions along with the related payback periods.     

European residential buildings and empirical assessment of the Hellenic building stock,energy consumption,emissions and potential energy savings

The existing building stock in European countries accounts for over 40% of final energy consumption in the European Union (EU) member states, of which residential use represents 63% of total energy consumption in the buildings sector. Consequently, an increase of building energy performance can constitute an important instrument in the efforts to alleviate the EU energy import dependency (currently at about 48%) and comply with the Kyoto Protocol to reduce carbon dioxide emissions. This is also in accordance to the European Directive (EPBD 2002/91/EC) on the energy performance of buildings, which is currently under consideration in all EU member states. This paper presents an overview of the EU residential building stock and focuses on the Hellenic buildings. It elaborates the methodology used to determine the priorities for energy conservation measures (ECMs) in Hellenic residential buildings to reduce the environmental impact from CO₂ emissions, through the implementation of a realistic and effective national action plan. A major obstacle that had to overcome was the need to make suitable assumptions for missing detailed primary data. Accordingly, a qualitative and quantitative assessment of scattered national data resulted to a realistic assessment of the existing residential building stock and energy consumption. This is the first time that this kind of aggregate data is presented on a national level. Different energy conservation scenarios and their impact on the reduction of CO₂ emissions were evaluated. Accordingly, the most effective ECMs are the insulation of external walls (33–60% energy savings), weather proofing of openings (16–21%), the installation of double-glazed windows (14–20%), the regular maintenance of central heating boilers (10–12%), and the installation of solar collectors for sanitary hot water production (50–80%).     

Life-cycle carbon and cost analysis of energy efficiency measures in new commercial buildings

Energy efficiency in new building construction has become a key target to lower nation-wide energy use. The goals of this paper are to estimate life-cycle energy savings, carbon emission reduction, and cost-effectiveness of energy efficiency measures in new commercial buildings using an integrated design approach, and estimate the implications from a cost on energy-based carbon emissions. A total of 576 energy simulations are run for 12 prototypical buildings in 16 cities, with 3 building designs for each building-location combination. Simulated energy consumption and building cost databases are used to determine the life-cycle cost-effectiveness and carbon emissions of each design. The results show conventional energy efficiency technologies can be used to decrease energy use in new commercial buildings by 20-30% on average and up to over 40% for some building types and locations. These reductions can often be done at negative life-cycle costs because the improved efficiencies allow the installation of smaller, cheaper HVAC equipment. These improvements not only save money and energy, but reduce a building’s carbon footprint by 16% on average. A cost on carbon emissions from energy use increases the return on energy efficiency investments because energy is more expensive, making some cost-ineffective projects economically feasible.     

可持续建筑的低碳设计战略

在我国建筑能耗持续增长的严峻形势下,一种综合性的可持续建筑低碳设计战略呼之欲出,以实现“十二五规划”纲要中节能、减排的约束性目标.列出了建筑节能领域的现行法律法规与设计标准,根据可持续发展的原始定义,提出环保、生态、节能、绿色、生物和气侯适应性建筑,都是可持续建筑的实现途径.着重阐述了可持续建筑的低碳设计战略,包括5个...     

Assessment of wastewater treatment technologies: life cycle approach

Four municipal wastewater treatment plants (WWTPs) in India based on different technologies are compared by conducting Life Cycle Assessment (LCA) using field data. CML 2 baseline 2000 methodology is adopted in which eight impact categories are considered. SBRs ranked highest in energy consumption and global warming potential (GWP) but also produced the best effluent with respect to organics and nutrients. Constructed wetlands have negligible energy consumption and negative GWP because of carbon sequestration in the macrophytes. Emissions associated with electricity production required to operate the WWTPs, emissions to water from treated effluent and heavy metal emissions from waste sludge applied to land are identified as main contributors for overall environmental impacts of WWTPs. This comparison of technologies suggests that results from LCA can be used as indicators in a multicriteria decision‐making framework along with other sustainability indicators.     

Awareness development for an energy management program for social housing in Canada

Social housing organizations compete with other social causes for limited public and private sector funding. While the environmental impact is important, it must be recognized that for most social housing organizations the most appealing aspect of an energy management program is the reduction in operating costs through reduced energy consumption. In order to secure financial resources for an energy management program, organizations will need to identify and address stakeholder perspectives in the formulation of ‘marketing’ strategies. The ‘marketing’ of an energy management program would be aimed at illustrating the substantial financial savings that can be achieved by increasing energy efficiency in social housing units. The bonus of an energy management program is the contribution towards environmental conservation and initiatives such as the Kyoto Protocol, as increased efficiency in energy usage and the subsequent reduction in overall energy consumption in social housing units contributes to reducing Canada’s greenhouse gas emissions.     

全国碳市场建设现状及水泥行业应对措施探讨

建材行业二氧化碳量排放的65%～67%来自水泥制造业,工艺环节的排放又占到水泥制造业二氧化碳排放的60%以上,面对全国碳市场即将于今年启动,水泥熟料作为首批纳入行业,基准值确定与碳配额的分配将直接关系到企业的履约成本。企业通过转变原料、能源消费方式,加大节能减排新技术的推行力度,结合碳资产的有效管理,不仅可以消除碳交易制度带来的影响,先进企业还可以做到在碳市场中有所盈利。     

An environmental assessment of wood and steel reinforced concrete housing construction

Wooden type of housing is ubiquitous in Japan. It is the main structure for housing; however, due to the increase in residential developments, steel reinforced concrete houses are also on the rise. This paper assesses the environmental impacts of these two types of construction. An evaluation of the two types of construction in terms of energy usage and air emissions is done. A comparison of the damage costs due to the generated emissions is also considered. Four types of emissions generated are evaluated, namely carbon emissions (CO₂), nitrogen oxides (NO_x), sulfur oxides (SO_x) and suspended particulate matter (SPM). The life cycle of the two different housing construction types is traced and environmental impacts are determined. External costs are also calculated. Furthermore, different improvement assessment scenarios are simulated to ascertain several emission reduction possibilities. The study looks into the emitted emissions from the housing construction to its final disposal of a typical residential development in Saga, Japan. Results show that much of the environmental impacts from building a house are on the Global Warming Potential due to high carbon emissions. Moreover, the construction phase generated the highest pollutant emissions from nitrogen oxides, sulfur oxides and suspended particulate matter. Steel reinforced concrete (SRC) construction has a higher environmental impact compared to the wooden type of housing construction. A longer design life for a residential house gives a reduction of about 14% in carbon emissions. Using solar energy for the operation phase has gained a reduction of 73% in the total life cycle carbon emissions.     

Inventory analysis of LCA on steel- and concrete-construction office buildings

A life-cycle inventory model for the office buildings is developed in this paper. The environmental effects of two different building structures, steel and concrete, are intercompared. The results show that the steel-framed building is superior to the concrete-framed building on the following two indexes, the life-cycle energy consumption and environmental emissions of building materials. It is found that the life-cycle energy consumption of building materials per area in the steel-framed building is 24.9% as that in the concrete-framed building, whereas, on use phase, the energy consumption and emissions of steel-framed building are both larger than those of concrete-framed building. As a result, lower energy consumption and environmental emissions are achieved by the concrete-framed building compared with the steel-framed building on the whole life cycle of building. The present study also provides a good method of assessing the performance of energy saving and environmental protection of different building structures based on a whole life cycle.     

Theoretical and experimental thermal performance assessment of an innovative external wall insulation system for social housing retrofit

The UK building stock,being amongst the oldest in the developed world,is also one of the least energy efficient and accounts for approximately 45% of UK carbon emission. Energy use from housing alone was responsible for 13% of total UK carbon dioxide and greenhouse gas emissions in 2015. Therefore,achieving the national target of an 80% reduction in carbon emissions by 2050 against 1990 baseline conditions is highly dependent on the reduction of energy consumption in dw ellings. The complexity of the problem of retrofitting energy saving measures in the extensive and diverse aging housing stock is further compounded due to the number of "hard to treat " properties that comprise over 40% of homes in the UK. In this article,the authors present an evaluation of the theoretical and experimental performances of a novel prototype external wall insulation system,developed to improve energy efficiency in "hard to treat"housing. The system was designed to be primarily used to retrofit social housing,w hich comprises up to 18% of the current UK housing stock.A thorough testing regime was undertaken to test the suitability and effectiveness of the new product in the most common social housing construction typologies. This included: an investigation of the theoretical thermal performance of the prototype product through steady state modelling,a laboratory based prototype test,an analysis of empirical data collected from a cross section of social housing properties in Nottinghamshire,UK used to inform whole house dynamic modelling,and the development of dynamic simulations to assess the energy and carbon reduction impacts of the new product. The theoretical modelling suggested that the integration of the system resulted in thermal performance improvements for all construction types with space heating demand reduced by up to 42%. The results of the whole house dynamic modelling assessment also suggested that the addition of the system resulted in a reduction of heating energy demand of up to 49%. The prototyping testing show n that the system is easy to install requirement minimum building skills.The findings suggest that the new product not only meets the performance of existing external wall insulation systems,but also provides unique selling points with respect to easy installation and non-reliance on weather conditions. The project finished with a pilot study when one house was retrofitted using the novel product.     

Evolution of energy policy in the Netherlands: past,present and future

In this paper, the past, present and possible future developments of energy policy for the built environment in the Netherlands are described briefly. The focus is on the development of and necessity for introducing new policy instruments for the built environment. Over the years, energy policy has evolved gradually to create a more integrated approach to the energy efficiency of buildings and larger urban districts. However, further evolution might be inevitable due to a shift of the primary driver for ‘energy’ policy from energy conservation to carbon dioxide reduction. Maximum targets of carbon dioxide emissions are being developed for each sector by 2010 and each sector has the obligation to meet its defined carbon dioxide reduction goal. Severe carbon dioxide reduction goals for the built environment in the Netherlands can only be achieved by means of energy efficiency improvement and fuel substitution, replacing natural gas with lower-carbon fuels. The introduction of lower-carbon fuels raises policy questions on whether to maintain the old infrastructure at great cost or whether investment should be in a new energy infrastructure and how this transition can be managed.