1、Unit32Application Status and Evaluation Method of Renewable Energy in Green Building in ChinaTextThe development of utilization of renewable energy is designated as the preferential area for energy development by The Renewable Energy Law of the Peoples Republic of China.Promoting large-scale utiliza
2、tion of solar energy and geothermal energy in building sector is one of targets of Middle and Long Term Program of Renewable Energy Development in China.Renewable energy utilization in building during the Twelfth Five-Year,is aimed at 2.5billion square meters of floor area,with estimated ability of
3、replacing conventional energy of 30 million tons of standard coal.The green building in China is defined to be“Four-Saving”and“Two-Benign”,namely land saving,energy saving,water saving and material saving,and benign to ambient environment and indoor environment,respectively.If buildings with renewab
4、le energy utilization comply with Evaluation Standard for Green building at the same time,they will be considered firstly in demonstration program and financial subsidy by the government.Therefore,evaluation on renewable energy utilization not only affects quality of green building,but concerns with
5、 governmental fund allocation.In this paper,application status of solar energy and geothermal energy in Green Building Label(GBL)projects is investigated at first.Then,characteristic features of provisions for evaluatingTextrenewable energy utilization in current Chinese national standard are analyz
6、ed.Its followed by introduction of evaluation method for renewable energy in other green building systems.At last,discussion on scientific and technical rationality of the evaluation method is proposed.Investigation sample here is 57 Green Building Label(GBL)projects evaluated by Chinese Society for
7、 Urban Studies by the end of the year of 2010.Among them,32GBL projects are dwellings,and the other 25 projects are public buildings.From another standpoint,GBL project quantity of one-star,two-star and three-star level is 11,25and 21,respectively.Dwellings There are 18 GBL projects with renewable e
8、nergy utilization,accounting 56%of dwelling GBL projects.Furthermore,quantity percentage of projects applying ground source heat pump(GSHP)and solar water heater(SWH)in all dwelling projects is 16%and 50%,respectively.These data suggest that 10%of dwelling projects takes use of both geothermal energ
9、y and solar energy.PV panel is not found in dwelling projects.GSHP is applied in 2 two-star projects and 3 three-star projects,which mostly are middle high rise building.units and installed cooling/heating capacity of the 5 projects.TextThe size of blue circle indicates installed cooling capacity of
10、 project in hot-summer and cold-winter zone,whereas that of red one indicates installed heating capacity of the project in cold zone.Regardless of this project,comprised of dwelling and commercial annex,cooling load of dwelling in hot-summer and cold-winter zone is estimated between 30W/and 35 W/.He
11、ating load of dwelling in cold zone is about 63 W/.SWH is applied in half of dwelling projects.project quantities in different solar energy area according to is given respectively.It should be fully recognized that,2one-star projects(including an indemnificatory housing project)apply SWH as well.Act
12、ually,part of units,especially those at lower floors,is not served by SWH,due to over-shading from adjacent buildings or water system pipe work.However,suggests linear correlation between solar collector area and units served by SWH.Generally,2.09 of solar collector is need for one unit.Public Build
13、ings There are 19 GBL projects with renewable energy utilization,accounting 76%of public building GBL projects.Furthermore,quantity percentage of projects applying GSHP,SWH and PV panel in all public building projects is 48%,44%and 32%,respectively.TextThere even are 4 projects applying all of three
14、 systems above.GSHP is applied in 4 two-star projects and 7 three-star projects.Among them,one three-star project is groundwater heat pump(GWHP);another is district heating and cooling(DHC)system using sea water heat pump(SWHP);the other 9 projects are ground-coupled heat pump(GCHP).as well.Cooling
15、load of public building is about 55 W/.projects applying SWH,and 8 projects applying.Obviously,the more the solar energy,the more projects applying SWH or PV.Whats more,the higher the GBL level,the more projects applying SWH or PV.Without exception,electricity energy generated by PV panel is put int
16、o electricity grid at low-voltage side.Power generation per unit area of most projects is in the rage of 100Wp/to 200Wp/.The national standard,Evaluation Standard for Green building(GB/T 50378-2006),is used to evaluate green building in China.Energy saving and energy resource utilization is one of s
17、ix categories of evaluation indices.Each category includes Prerequisite Provisions,Optional Provisions and Optimal Provisions.TextAll Prerequisite Provisions must be met regardless of GBL star level,whereas Optional Provisions and Optimal Provisions both have different compliance requirements for ea
18、ch level.Furthermore,compliance number of Optional Provisions is required respectively by each category,but Optimal Provisions in all six categories require compliance number only once.A.DwellingIn the standard,there are one Optional Provision and one Optimal Provision for evaluating renewable energ
19、y utilization of dwelling projects.Both of them take consumption ratio of renewable energy to total energy in building as evaluation index.Index value of the former provision is 5%,whereas that of the latter one is 10%.That is intended to encourage fully utilization on renewable energy.For convenien
20、ce,the Optional Provision for renewable energy utilization can be determined compliance if one of three following conditions is satisfied:More than 25%of units in the dwelling or community apply SHW for domestic hot water supply;More than 25%of units in the dwelling or community apply GSHP for space
21、 heating and/or cooling;or More than 50%of units in the dwelling or community apply geothermal water for space heating directly.TextAs for the Optimal Provision,the value for three conditions above increase to 50%,50%and 100%,respectively.Obviously,the GBL project in compliance with the Optimal Prov
22、ision,definitely complies with the Optional Provision.However,project proportion complying the Optional Provision and the Optimal Provision for renewable energy utilization in 32 dwellings investigated,is 56%and 50%,respectively.In other words,all projects applying renewable energy comply with the O
23、ptional Provision,and mostly comply with the Optimal Provision.projects failing in the Optional Provision,are both high-rise and applying solar hot water system.The separate set of evaluation provision on renewable energy utilization has little meaning.B.Public BuildingIn the standard,there is one O
24、ptimal Provision for evaluating renewable energy utilization of public building projects.Other than the index of renewable energy consumption ratio for dwelling,the Optional Provision takes evaluation index as follows:Domestic hot water liters produced by SHWTextmore than 10%of total consumption of
25、domestic hot water in building;Power generated by PV more than 2%of total consumption of electricity in building;or GSHP for space heating and/or cooling.In the 25 public building projects under study,68%complies with the provision.2 projects with renewable energy utilization failed in this provisio
26、n,one high-rise office applying SWH,the other one applying PV panel experimentally.C.Summary and AnalysisProvisions in current national standard,have set technical threshold for renewable energy utilization in green building successfully.However,they need to be improved in following aspects:Rational
27、ity of index values.It should be illustrated or explained how these values are determined and why those three conditions equal to each other.Basic study and specialized research need to be conducted.Uniformity of calculating means.Provision of template and/or sample files would be a good solution.Tr
28、ade off between scientific and convenience of evaluation method.Although a discord may arise over this issue,further investigation and study is implemented below.TextOTHER EVALUATION METHODSIn other green building evaluation or assessment systems,there are diverse types of evaluation method on renew
29、able energy utilization.The first one is renewable energy percentage in LEED(Lead ship in Energy and Environmental Design).The second one is renewable energy usage per unit floor area in CASBEE(Comprehensive Assessment System for Built Environment Efficiency).The third one is consideration in Energy
30、 Performance Ratio(EPR)calculation in BREEAM(Building Research Establishment Environmental Assessment Method),other than direct evaluation of the former two types.Renewable Energy Percentage Taking LEED 2009 for New Construction and Major Renovations as an example,evaluation index is a percentage of
31、 energy produced by renewable systems to the buildings annual energy cost.Points up to 7 could be achieved in case of the percentage larger than 13%.Other methods taking percentage as the evaluation index,include percentage of renewable primary energy in DGNB(German Sustainable Building Certificate)
32、,replacement percentage of electricity in Green Mark for New Buildings Version 4.0 from Singapore,and the ratio of renewable energy to total energy in current Chinese national standard.TextRenewable Energy Usage The evaluation index in CASBEE for New Construction 2008 Edition,is annual renewable ene
33、rgy usage per unit floor area,with the unit of“MJ/(yr)”.Different levels will be determined by index value of 1 MJ/(yr)and 15 MJ/(yr).Besides converted(or indirect)use of renewable energy mentioned above,including PV generation,solar heat utilization and other semi-mechanical means,there is direct u
34、tilization form of natural energy in CASBEE as well,e.g.natural light,natural ventilation,geothermal energy(not GSHP).Indirect Evaluation by Energy Performance Ratio Considering that renewable energy is used to off-set or reduce regular energy cost/consumption,BREEAM 2011 for New Construction(Non-Do
35、mestic Buildings)takes Energy Performance Ratio(EPR)of all systems and equipments in building as the evaluation index,instead of evaluating renewable energy utilization individually.DISCUSSIONRevision on current Chinese national standard is underway,both application status and evaluation investigati
36、on in this paper could be helpful for renewable energy evaluation in the standard.Although the evaluation methods in all evaluation or assessment systems above are easy to be understand and implement,scientific and technical rationality should be considered more from follow-Text-ing aspects:Extra en
37、ergy consumption(especially for GSHP).According to the Second Law of Thermodynamics,entropy and exergy could be applied to evaluate both quantity and quality of renewable energy utilization.Moreover,differences between various renewable energy,such as solar energy and geothermal energy are taken int
38、o account at the same time.Relative study has been conducted by Xia and Hepbasli.Regional disparity of renewable energy resources.Distribution of almost all kinds of energy resources,including renewable ones,varies with different regions.Those index values mentioned above are uniform but not fair fo
39、r them.Local level of renewable energy resources should be one of input variables when evaluating.Evaluation path in energy related topic.If there is a performance path focus on total energy cost/consumption or energy-saving rate,it is better to avoid double counting renewable energy percentage or u
40、sage mentioned above,just like the EPR way in BREEAM.If not,evaluation in energy related topic would cover separate ones on building envelope,service system efficiency,renewable energy utilization,etc.Weighting on renewable energy in the whole system.Reasonable solution to energy-saving would be fol
41、lowing steps:modest parameter of indoor environment to reduce energy requirement,appropriate building and its envelope to use natural energy directly and hence reduce system load,high efficiency building service systems and equipments to reduce energy use,and then renewable energy utilization to red
42、uce regular energy use.These should be noticed when distributing weights.solar energy太阳能renewable energy可再生能源subsidyn.补贴；津贴；助学金；奖金samplen.样品，华样；标本，榜Green Building绿色建筑Dwellingn.住处，处所；寓所；居住Utilizationn.利用，使用，效用Pumpn.泵；打气筒solar collector太阳能收集器，太阳能吸收器geothermaladj.地热的，地温的installvt.安装；安顿，cooling capacity
43、冷却能力quantity n.量，数量；定量，大批district heating 区域供暖；区域集中供热；grid n.格子；地图上的坐标方格；（输电线路、天然气管道等的）系统网络panel n.镶板；面consumption ratio 消费率Provision n.规定，条项high-rise n.高楼，大厦，多层建筑物implement vt.实施，执行；使生效semi-mechanical 半机械化system efficiency 系统效率New Words and PhrasesNotes（1）The development of utilization of renewable
44、 energy is designated as the preferential area for energy development by The Renewable Energy Law of the Peoples Republic of China.Energy saving and energy resource utilization is one of six categories of evaluation indices.可再生能源的开发利用被指定为受中华人民共和国可再生能源优先发展的领域。节能与能源利用是六项评价指标中的一种。（2）The green building
45、in China is defined to be“Four-Saving”and“Two-Benign”,namely land saving,energy saving,water saving and material saving,and benign to ambient environment and indoor environment,respectively.绿色建筑在中国被定义为“四个节约”，两个“有利于”，也就是土地节约，能源节约，水资源节约和材料节约，并且有利于外部环境和内部环境。（3）The national standard,Evaluation Standard
46、for Green building,is used to evaluate green building in China国家标准是绿色建筑的评价标准，过去常常用于在中国评价绿色建筑方面。Notes（4）In the standard,there are one Optional Provision and one Optimal Provision for evaluating renewable energy utilization of dwelling projects.Both of them take consumption ratio of renewable energy t
47、o total energy in building as evaluation index.在标准中，对住宅项目的可再生能源利用评价有可选措施和最优措施。它们都以可再生能源在建筑总能耗消费的比例作为评价指标。（5）In other green building evaluation or assessment systems,there are diverse types of evaluation method on renewable energy utilization.在其他绿色建筑评价或评估系统中，还有一些不同类型的可再生能源利用评价方法。1.Renewable energy ut
48、ilization in building during the Twelfth Five-Year,is aimed at 2.5billion square meters of floor area,with estimated ability of replacing conventional energy of 30 million tons of standard coal.2.If buildings with renewable energy utilization comply with Evaluation Standard for Green building at the
49、 same time,they will be considered firstly in demonstration program and financial subsidy by the government.Therefore,evaluation on renewable energy utilization not only affects quality of green building,but concerns with governmental fund allocation.3.Dwellings There are 18 GBL projects with renewa
50、ble energy utilization,accounting 56%of dwelling GBL projects.Furthermore,quantity percentage of projects applying ground source heat pump(GSHP)and solar water heater(SWH)in all dwelling projects is 16%and 50%,respectively.4.The circle in lower left corner represents the only one high rise building,
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