The California Simulation of Evapotranspiration of Applied Water (CaI-SIMETAW) model is a new tool developed by the California Department of Water Resources and the University of California, Davis to perform daily s...The California Simulation of Evapotranspiration of Applied Water (CaI-SIMETAW) model is a new tool developed by the California Department of Water Resources and the University of California, Davis to perform daily soil water balance and determine crop evapotranspiration (ETo), evapotranspiration of applied water (ETaw), and applied water (AW) for use in California water resources planning. ETaw is a seasonal estimate of the water needed to irrigate a crop assuming 100% irrigation efficiency. The model accounts for soils, crop coefficients, rooting depths, seepage, etc. that influence crop water balance. It provides spatial soil and climate information and it uses historical crop and land-use category information to provide seasonal water balance estimates by combinations of detailed analysis unit and county (DAU/County) over Califomia. The result is a large data base of ETc and ETaw that will be used to update information in the new California Water Plan (CWP). The application uses the daily climate data, i.e., maximum (Tx) and minimum (Tn) temperature and precipitation (Pcp), which were derived from monthly USDA-NRCS PRISM data (PRISM Group 2011) and daily US National Climate Data Center (NCDC) climate station data to cover California on a 4 kmx4 km change grid spacing. The application uses daily weather data to determine reference evapotranspiration (ETo), using the Hargreaves-Samani (HS) equation (Hargreaves and Samani 1982, 1985). Because the HS equation is based on temperature only, ETo from the HS equation were compared with CIMIS ETo at the same locations using available CIMIS data to determine correction factors to estimate CIMIS ETo from the HS ETo to account for spatial climate differences. CaI-SIMETAW also employs near real-time reference evapotranspiration (ETo) information from Spatial CIMIS, which is a model that combines weather station data and remote sensing to provide a grid of ETo information. A second database containing the available soil water holding capacity and soil depth information for all of California was also developed from the USDA-NRCS SSURGO database. The Cal-SIMETAW program also has the ability to generate daily weather data from monthly mean values for use in studying climate change scenarios and their possible impacts on water demand in the state. The key objective of this project is to improve the accuracy of water use estimates for the California Water Plan (CWP), which provides a comprehensive report on water supply, demand, and management in California. In this paper, we will discuss the model and how it determines ETaw for use in water resources planning.展开更多
High temperature and humidity can be controlled in greenhouses by using mechanical refrigeration cooling system such as air conditioner(AC)in warm and humid regions.This study aims to evaluate the techno-financial asp...High temperature and humidity can be controlled in greenhouses by using mechanical refrigeration cooling system such as air conditioner(AC)in warm and humid regions.This study aims to evaluate the techno-financial aspects of the AC-cooled greenhouse as compared to the evaporative cooled(EV-cooled)greenhouse in winter and summer seasons.Two quonset single-span prototype greenhouses were built in the Agriculture Experiment Station of Sultan Qaboos University,Oman,with dimensions of 6.0 m long and 3.0 m wide.The AC-cooled greenhouse was covered by a rockwool insulated polyethylene plastic sheet and light emitting diodes(LED)lights were used as a source of light,while the EV-cooled greenhouse was covered by a transparent polyethylene sheet and sunlight was used as light source.Three cultivars of high-value lettuce were grown for experimentation.To evaluate the technical efficiency of greenhouse performance,we conducted measures on land use efficiency(LUE),water use efficiency(WUE),gross water use efficiency(GWUE)and energy use efficiency(EUE).Financial analysis was conducted to compare the profitability of both greenhouses.The results showed that the LUE in winter were 10.10 and 14.50 kg/m^(2) for the AC-and EV-cooled greenhouses,respectively.However,the values reduced near to 6.80 kg/m^(2) in both greenhouses in summer.The WUE of the AC-cooled greenhouse was higher than that of the EV-cooled greenhouse by 3.8%in winter and 26.8%in summer.The GWUE was used to measure the total yield to the total greenhouse water consumption including irrigation and cooling water;it was higher in the AC-cooled greenhouse than in the EV-cooled greenhouse in both summer and winter seasons by almost 98.0%–99.4%.The EUE in the EV-cooled greenhouse was higher in both seasons.Financial analysis showed that in winter,gross return,net return and benefit-to-cost ratio were better in the EVcooled greenhouse,while in summer,those were higher in the AC-cooled greenhouse.The values of internal rate of return in the AC-and EV-cooled greenhouses were 63.4%and 129.3%,respectively.In both greenhouses,lettuce investment was highly sensitive to changes in price,yield and energy cost.The financial performance of the AC-cooled greenhouse in summer was better than that of the EV-cooled greenhouse and the pattern was opposite in winter.Finally,more studies on the optimum LED light intensity for any particular crop have to be conducted over different growing seasons in order to enhance the yield quantity and quality of crop.展开更多
The Chinese government is developing biomass ethanol as one of its automobile fuels for energy security and environmental improvement reasons. The energy efficiency of the biomass-based fuel ethanol is critical issue....The Chinese government is developing biomass ethanol as one of its automobile fuels for energy security and environmental improvement reasons. The energy efficiency of the biomass-based fuel ethanol is critical issue. To investigate the energy use in the three biomass-base ethanol fuel systems, energy content approach, Market value approach and Product displacement approach methods were used to allocate the energy use based on life cycle energy assessment. The results shows that the net energy of corn based, wheat based, and cassava-based ethanol fuel are 12543MJ, 10299MJ and 13112MJ when get one ton biomassbased ethanol, respectively, and they do produce positive net energy.展开更多
This article discusses cnergy-ficicnt rtfitting design strategics for commercial office buildings,and cxamincs thcir ffect on energy consumption.The objective of the rescarch was to study how to intcgrate passive desi...This article discusses cnergy-ficicnt rtfitting design strategics for commercial office buildings,and cxamincs thcir ffect on energy consumption.The objective of the rescarch was to study how to intcgrate passive design stratcgics and cnergy-efficient building systems to improve building performancc,and reduce the cncrgy consumption of existing buildings in three different climate types(cold,mixed and hot climates).First,propertics of existing buildings were analyzed based on national CBECS database to detcrminc typical charactcristics of office buildings located in Chicago,Baltimore and Phoenix,including size,building envelope treatment and building systems.Then,fourteen diffrent prototypes were developed,varying the building shape and orientation to represent different building stock,and cncrgy modcling was conducted to cstablish energy usage baselinc.Multiplc design con-sidcrations were investigated bascd on cxtensivc cncrgy simulations and modeling;where low-impact and decp retrofits were considered.Low-impact stratcgics included improvements to the building cnvelope,lighting systems and optimization of HVAC systems opcration(without upgrading heating and cooling cquipment).Decp cnergy rctrofits also included improvements to building envclopc and lighting,and con-sidered changcs and improvements to HVAC systems(spccifically,integration of radiant systcms).Energy modeling was conducted for all prototypes,and results were obtained for the bascline(current energy usagc),and energy usage considering low-impact design stratcgics and decp rctrofts.A total of 126 cnergy modcls was devcloped,simulated and analyzed,providing a dataset that captured cnergy usage for investigated scenarios.The comparative analysis of simulation results was used to determine how specific techniqucs lead to energy savings in different climatc types,as well as for buildings of various shapes and oricntations.展开更多
Developing a green economy is key to achieving the 2030 Sustainable Development Goals. This paper uses the SBM-GML index, which includes non-desired outputs, to measure the trend of regional green economic efficiency ...Developing a green economy is key to achieving the 2030 Sustainable Development Goals. This paper uses the SBM-GML index, which includes non-desired outputs, to measure the trend of regional green economic efficiency changes and analyze the impact mechanism and realization path of industrial transformation on green economic efficiency. The research results show that advanced industrial structure has a positive influence on green economic efficiency nationwide, while energy utilization structure and energy utilization efficiency have positive partial intermediary effects in the influence path;industrial structure rationalization is also significantly positively related to green economic efficiency nationwide, and the mediating effect of energy utilization is positive. The impact of industrial transformation on green economic efficiency has regional heterogeneity, and the mediating effect of energy use also differs. Among them, the impact effect in the eastern region is basically consistent with the national sample, but is negative in the central and western regions. This paper proposes countermeasures in terms of adjusting the industrial structure, improving energy efficiency, and perfecting industrial and energy policies, which can provide theoretical and practical references for promoting the transformation and upgrading of regional industrial structure, optimizing energy utilization, and advancing the efficiency of the national and regional green economy.展开更多
The“average occupant”methodology is widely used in energy consumption simulations of residential buildings;however,it fails to consider the differences in energy use behavior among family members.Based on a field su...The“average occupant”methodology is widely used in energy consumption simulations of residential buildings;however,it fails to consider the differences in energy use behavior among family members.Based on a field survey on the Central Shaanxi Plain,to identify the energy use behavior patterns of typical families,a stochastic energy use behavior model considering differences in energy use behavior among family members was proposed,to improve the accuracy of energy consumption simulations of residential buildings.The results indicated that the surveyed rural families could be classified into the following four types depending on specific energy use behavior patterns:families of one elderly couple,families of one middle-aged couple,families of one elderly couple and one child,and families of one couple and one child.Moreover,on typical summer days,the results of daily building energy consumption simulation obtained by the“average occupant”methodology were 25.39%and 28%lower than the simulation results obtained by the model proposed in this study for families of one elderly couple and families of one middle-aged couple,and 13.05%and 23.05%higher for families of one elderly couple and one child,and families of one couple and one child.On typical winter days,for the four types of families,the results of daily building energy consumption simulation obtained by the“average occupant”methodology were 21.69%,10.84%,1.21%,and 8.39%lower than the simulation results obtained by the model proposed in this study,respectively.展开更多
As the largest energy consuming manufacturing sector and one of the most important sources of carhon dioxide (CO2) emissions, the China's iron and steel industry has paid attention to the study of changing trend an...As the largest energy consuming manufacturing sector and one of the most important sources of carhon dioxide (CO2) emissions, the China's iron and steel industry has paid attention to the study of changing trend and influencing factors of CO2 emissions from energy use. The logarithmic mean Divisia index (LMD1) technique is used to decompose total change in CO2 emissions into four factors: emission factor effect, energy structure effect, energy consumption effect, and steel production effect. The results show that the steel production effect is the major factor which is responsible for the rise in CO2 emissions; whereas the energy consumption effect contributes most to the reduction in CO2 emissions. And the emission factor effect makes a weak negative contribution to the increase of CO2 emis- sions. To find out the detailed relationship between change in energy consumption or steel production and change in CO2 emissions, the correlation equations are also proposed.展开更多
Red plus blue light-emitting diodes(LEDs)are commonly applied in plant factories with artificial lighting due to photosynthetic pigments,which absorb strongly in red and blue light regions of the spectrum.However,plan...Red plus blue light-emitting diodes(LEDs)are commonly applied in plant factories with artificial lighting due to photosynthetic pigments,which absorb strongly in red and blue light regions of the spectrum.However,plants grown under natural environment are used to utilizing broad-wide spectrum by long-term evolution.In order to examine the effects of addition light added in red plus blue LEDs or white LEDs,green and purple leaf lettuces(Lactuca sativa L.cv.Lvdie and Ziya)were hydroponically cultivated for 20 days under white LEDs,white plus red LEDs,red plus blue LEDs,and red plus blue LEDs supplemented with ultraviolet,green or far-red light,respectively.The results indicated that the addition of far-red light in red plus blue LEDs increased leaf fresh and dry weights of green leaf lettuce by 28%and 34%,respectively.Addition of ultraviolet light did not induce any differences in growth and energy use efficiency in both lettuce cultivars,while supplementing green light with red plus blue LEDs reduced the vitamin C content of green leaf lettuce by 44%and anthocyanin content of purple leaf lettuce by 30%compared with red plus blue LEDs,respectively.Spectral absorbencies of purple leaf lettuce grown under red plus blue LEDs supplemented with green light were lower in green light region compared with those grown under red plus blue LEDs,which was associated with anthocyanin contents.White plus red LEDs significantly increased leaf fresh and dry weights of purple leaf lettuce by 25%,and no significant differences were observed in vitamin C and nitrate contents compared with white LEDs.Fresh weight,light and electrical energy use efficiencies of hydroponic green and purple leaf lettuces grown under white plus red LEDs were higher or no significant differences compared with those grown under red plus blue LEDs.In conclusion,white plus red LEDs were suggested to substitute for red plus blue LEDs in hydroponic lettuce(cv.Lvdie and Ziya)production in plant factories with artificial lighting.展开更多
The aim of this research is to conduct an energy use efficiency and greenhouse gas(GHG)emission analysis in watermelon production that took place in Kırklareli Province of Turkey during the 2021 production season.This...The aim of this research is to conduct an energy use efficiency and greenhouse gas(GHG)emission analysis in watermelon production that took place in Kırklareli Province of Turkey during the 2021 production season.This research contains calculations of Energy use efficiency,specific energy,energy productivity and net energy,energy input types,GHG emissions and GHG ratio.Survey,observation and data calculations are related to the 2021 production season.The data used in the research were collected from 30 different(accessible)farms through face-to-face surveys with full count method.EI and EO were calculated as 15698.99 MJ/hm^(2)and 104784.91 MJ/hm^(2),respectively.In relation to production inputs,24.29%of the energy inputs consisted of chemical fertilizers energy(3813.34 MJ/hm^(2)),20.04%consisted of transportation energy(3146.19 MJ/hm^(2)),10.63%consisted of diesel fuel energy(1668.52 MJ/hm^(2)),7.44%consisted of human labour energy(1168.09 MJ/hm^(2)),6.50%consisted of plant energy(1021.02 MJ/hm^(2)),5.76%consisted of electricity energy(904.50 MJ/hm^(2)),5.18%consisted of machinery energy(813.44 MJ/hm^(2)),3.36%consisted of irrigation water energy(527.63 MJ/hm^(2)),2.85%consisted of organic fertilizer energy(446.72 MJ/hm^(2)),2.40%consisted of farmyard manure energy(376.62 MJ/hm^(2))and 0.67%consisted of chemicals energy(105.67 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy were calculated as 6.67,0.28 MJ/kg,3.51 kg/MJ and 89085.91 MJ/hm^(2),respectively.The utilized total energy input in production was grouped as 27.19%direct energy,72.81%indirect energy,22.55%renewable energy and 77.45%nonrenewable.Total GHG emissions and GHG ratio were determined as 492.82 kg CO_(2)-eq/hm^(2),0.01 kg CO_(2)-eq/kg,respectively.展开更多
This study has been conducted with the purpose of determining energy use efficiency and greenhouse gas emissions of garlic cultivation during the 2020-2021 cultivation season in Adıyaman province of Turkey.Questionnai...This study has been conducted with the purpose of determining energy use efficiency and greenhouse gas emissions of garlic cultivation during the 2020-2021 cultivation season in Adıyaman province of Turkey.Questionnaires,observations and field works were performed in 134 garlic farms in the region through simple random method.In garlic cultivation,energy input was calculated as 32103.20 MJ/hm^(2)and energy output was calculated as 30096 MJ/hm^(2).With regards to the three highest inputs in garlic production,46.66%of the energy inputs consisted of chemical fertilizers energy(14979.26 MJ/hm^(2)),11.29%consisted of farmyard manure energy(3625.71 MJ/hm^(2))and 10.48%consisted of human labour energy(3363.36 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy in garlic cultivation were calculated as 0.94,1.71 MJ/kg,0.59 kg/MJ,and−2007.20 MJ/hm^(2),respectively.The total energy input consumed in garlic cultivation was classified as 27.19%direct energy,72.81%indirect energy,35.17%renewable energy and 64.87%nonrenewable energy.Total GHG emissions and GHG ratio were calculated as 8636.60 kg CO_(2)-eq/hm^(2)and 0.46 kg CO_(2)-eq/kg,respectively.展开更多
To enhance the transplants’growth and reduce energy use efficiency,Eggplant(Solanum melongena L.)transplants(cv.Jingqie 21)were cultivated in a plant factory laboratory under different LED light spectrums.The experim...To enhance the transplants’growth and reduce energy use efficiency,Eggplant(Solanum melongena L.)transplants(cv.Jingqie 21)were cultivated in a plant factory laboratory under different LED light spectrums.The experimental treatments included white plus blue LED lights(R:B=0.5,WB0.5),white LED lights(R:B=0.9,W0.9),white plus red LED lights(R:B=2.7,WR2.7),white plus red plus UV lights(R:B=3.8,WRUV3.8),and red plus blue plus green LED lights(R:B=5.4,RBG5.4).The transplants were grown for 30 d under a light intensity of 250μmol/m2·s and a photoperiod of 16 h/d.The morphological indicators and biomass accumulation of eggplant transplants were significantly higher in the W0.9 treatment compared to the other experimental treatments.The photosynthetic quantum yield in the W0.9 treatment exhibited an increase of over 22%compared to that in the WR2.7 treatment.The shoot dry weight of the W0.9 treatment reached(381±41)mg/plant and the leaf area was(113.3±8.9)cm^(2),indicating a higher health index compared to the other treatments.However,there were no significant differences in the net photosynthetic rate of the leaves among all treatments.The energy yield(EY)of the W0.9 treatment was(37.7±1.8)g/kW·h,which was higher than others.Therefore,considering the high quality of transplants and the maximization of energy use efficiency,the LED light spectrum in the eggplant transplants production was recommended to the white LED light with an R:B ratio of 0.9.展开更多
(Quoted from the 1Announcement and Call for Papers) The workshop is aimed at encouraging the use of biomass forenergy production and sustainable development, in particular, inthe field of China’s energy supply. In or...(Quoted from the 1Announcement and Call for Papers) The workshop is aimed at encouraging the use of biomass forenergy production and sustainable development, in particular, inthe field of China’s energy supply. In order to develop a sustain-able (economic, environmentally friendly and sound for futuregenerations) energy supply, pollution caused by emissions duringenergy generation needs to be reduced, and existing resources展开更多
The purpose of this study was to determine the energy use efficiency and greenhouse gas(GHG)emissions in peach production that took place in Kırklareli province of Turkey during the 2020-2021 production season.This st...The purpose of this study was to determine the energy use efficiency and greenhouse gas(GHG)emissions in peach production that took place in Kırklareli province of Turkey during the 2020-2021 production season.This study included calculations of energy input,energy output,energy use efficiency,specific energy,energy productivity,net energy,energy input types,GHG emissions and GHG ratio.Survey,observation and data calculations are related to the 2020-2021 production season.The data obtained from the study were collected from 16 different farms(reachable)through face-to-face surveys with full count method.Energy input and energy output were calculated as 19570.58 MJ/hm^(2) and 19471.94 MJ/hm^(2),respectively.With regards to production inputs,55.70% of the energy inputs consisted of chemical fertilizers energy(10900.03 MJ/hm^(2)),9.46% consisted of chemicals energy(1852.10 MJ/hm^(2)),9.32% consisted of human labour energy(1823.13 MJ/hm^(2)),7.65% consisted of electricity energy(1497.28 MJ/hm^(2)),6.91% consisted of diesel fuel energy(1351.52 MJ/hm^(2)),4.73% consisted of irrigation water energy(926.10 MJ/hm^(2)),3.43% consisted of machinery energy(671.98 MJ/hm^(2)),1.88% consisted of transportation energy(367.72 MJ/hm^(2)),0.88% consisted of farmyard manure energy(171.80 MJ/hm^(2))and 0.05%consisted of lime energy(8.94 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy were calculated as 0.99,1.91 MJ/kg,0.52 kg/MJ and-98.64 MJ/hm^(2),respectively.The consumed total energy input in production was classified as 28.60% direct energy,71.40% indirect energy,14.93% renewable energy and 85.07% non-renewable.Total GHG emissions and GHG ratio were calculated as 1683.24 kgCO_(2)-eq/hm^(2) and 0.16 kg CO_(2)-eq/kg,respectively.展开更多
The energy use of Bitcoin is fiercely debated among academics,practitioners,and the general public.This debate is often biased and characterized by a lack of understanding.Therefore,I start this paper with a discussio...The energy use of Bitcoin is fiercely debated among academics,practitioners,and the general public.This debate is often biased and characterized by a lack of understanding.Therefore,I start this paper with a discussion of the fundamentals of Bitcoin,which includes the clarification of widely held misconceptions.Next,I illustrate how Bitcoin is related to energy and describe the underlying incentive mechanism.In the main body of the paper,I discuss various components of Bitcoin’s energy use,including the amount,composition,and geographical distribution of the energy,as well as emerging positive and negative effects.These components are then combined into a comprehensive framework that provides a solid foundation for future academic research and presents practitioners with the big picture of how and why Bitcoin requires energy and whether this can be justified from an environmental point of view.展开更多
During metal machining, the satisfactoriness of cost-quality-time matrix convergence effectively depends on the supreme selection of cutting parameters. This study investigated the energy use minimisation and quality ...During metal machining, the satisfactoriness of cost-quality-time matrix convergence effectively depends on the supreme selection of cutting parameters. This study investigated the energy use minimisation and quality surface generation through optimised cutting parameters application, as sustainability enhancement during dry turning of EN19 material. Cutting parameter optimisation is a serious challenge confronting the machining industry as they strive to achieve low energy use and better component quality generation from their operations. The utility material, EN19, is a medium-carbon low alloy steel which typically gets applied in the manufacturing of multiple profiled cylindrical machine tool, rail locomotives and motor vehicle component parts, inter alia. Taguchi Full Factorial experimental plan was used to organise the empirical experiments. ANOVA and the main effects plot signal-to-noise ratio optimisation analysis were utilised in the study to establish the influence of process parameters on the response parameters—surface roughness and energy use. The aim was to investigate and determine the correlation of the machining strategy parameters with the outcome of low energy use and quality surface texture of the components as the cutting parameters were varied, and optimised for minimum surface roughness and energy use. Results of the extensive experimental study, produced optimum cutting speed, rake angle variation and feed rate which respectively influence the response parameters positively for energy use minimisation and improved surface quality. Validation experiments confirmed model findings.展开更多
Energy used for industrial production, buildings and transport will be accumulated in Atmosphere and Earth land. Global use of energy is known and documented for a long period of time and proportion of fossil and rene...Energy used for industrial production, buildings and transport will be accumulated in Atmosphere and Earth land. Global use of energy is known and documented for a long period of time and proportion of fossil and renewable energy is also known. Calculated accumulated energy in Earth land from 1971 to 2018 corresponds to 40% of IPCC Global Energy Inventory and calculated Atmosphere temperature increase from 1971 to 2018 corresponds to 100% of actual measurements.展开更多
Consider the task of tracking the energy use of an entire city while also working to reduce it by 50%in 17 years.How would you go about tracking and verifying such reductions?Further,how would this be accomplished in ...Consider the task of tracking the energy use of an entire city while also working to reduce it by 50%in 17 years.How would you go about tracking and verifying such reductions?Further,how would this be accomplished in a city without a database of building-specific characteristics and no energy reporting law?To begin,let’s consider what this task would look like for one building.Where to start?Let’s try with a performance metric and point of comparison.Just as cars gauge performance by MPG,and pitchers by ERA,buildings can use Energy Use Intensity(EUI)as a performance metric.Measured in Energy/ft2/year,EUI standardizes energy use per square foot,allowing for comparison between many buildings.EUI is a snapshot of building performance over one year’s time.It is relatively easy to calculate a building’s EUI if their energy usage is known,but in order to gauge performance over a longer period,a constant comparison point must be established so that evaluation is consistent.Called the baseline,this comparison point can be established as a past year,a future goal,or the average performance of similar buildings.This paper covers the work of the Pittsburgh 2030 District team in formulating an energy performance baseline for each building in Downtown Pittsburgh for purposes of tracking energy use reduction towards the 50%reduction goals of The 2030 Challenge.Pittsburgh is a city with a large stock of aging buildings,without mandatory benchmarking laws,and no single publicly accessible real estate profile by property.Thus,the energy baseline methods included in this paper summarize efforts to create such an aggregated property characteristic database and associated energy baseline for Downtown Pittsburgh;it is the hope of the authors that these efforts will assist similar cities in mirroring 2030 District goal setting and achievement for building energy.展开更多
This study develops a bottom-up model to quantitatively assess the comprehensive effects of replacing traditional petroleum-powered vehicles with natural gas vehicles(NGVs) in China based on an investigation of the ...This study develops a bottom-up model to quantitatively assess the comprehensive effects of replacing traditional petroleum-powered vehicles with natural gas vehicles(NGVs) in China based on an investigation of the direct energy consumption and critical air pollutant(CAP) emission intensity, life-cycle energy use and greenhouse gas(GHG) emission intensity of NGV fleets. The results indicate that, on average, there are no net energy savings from replacing a traditional fuel vehicle with an NGV. Interestingly, an NGV results in significant reductions in direct CAP and life-cycle GHG emissions compared to those of a traditional fuel vehicle, ranging from 61% to 76% and 12% to 29%, respectively. Due to the increasing use of natural gas as a vehicle fuel in China(i.e. approximately 28.2 billion cubic metres of natural gas in2015), the total petroleum substituted with natural gas was approximately 23.8 million tonnes(Mt), which generated a GHG emission reduction of 16.9 Mt of CO2 equivalent and a CAP emission reduction of 1.8 Mt in 2015. Given the significant contribution of NGVs, growing the NGV population in 2020 will further increase the petroleum substitution benefits and CAP and GHG emission reduction benefits by approximately 42.5 Mt of petroleum-based fuel, 3.1 Mt of CAPs and 28.0 Mt of GHGs. By 2030, these benefits will reach 81.5 Mt of traditional petroleum fuel, 5.6 Mt of CAPs and 50.5 Mt of GHGs, respectively.展开更多
With rapid economy growth,building energy consumption in China has been gradually increased.The energy consumption and indoor environmental quality of 51 office buildings in Hainan Province,a hot and humid area,were s...With rapid economy growth,building energy consumption in China has been gradually increased.The energy consumption and indoor environmental quality of 51 office buildings in Hainan Province,a hot and humid area,were studied through collection of verified data in site visits and field tests.The result revealed that,electricity accounted for 99.79% of the total energy consumption,natural gas 0.17%,and diesel 0.04%.The air conditioning dominated the energy use with a share of 43.18%,equipment in the particular areas 26.90%,equipment in the office rooms 11.95%,lighting system 8.67%,general service system 7.57%,and miscellaneous items 1.73%.Statistical method including six indicators obtained the energy consumption benchmark with upper limit of 98.31 kW-h/m2 and lower limit of 55.26 kW-h/m2.According to ASHRAE standard(comfortable standard) and GB/T 18883-2002(acceptable standard),the indoor environmental quality of 51 sampled office buildings was classified into three ranks:good,normal and bad.With benchmark of building energy consumption combined with indoor environmental quality,it was found that only 3.92% of sampled buildings can be identified as the best performance buildings with low energy consumption and advanced indoor environmental quality,and the buildings classified into normal level accounted for the maximum ratio.展开更多
基金supported and funded by the California Department of Water Resources(DWR)
文摘The California Simulation of Evapotranspiration of Applied Water (CaI-SIMETAW) model is a new tool developed by the California Department of Water Resources and the University of California, Davis to perform daily soil water balance and determine crop evapotranspiration (ETo), evapotranspiration of applied water (ETaw), and applied water (AW) for use in California water resources planning. ETaw is a seasonal estimate of the water needed to irrigate a crop assuming 100% irrigation efficiency. The model accounts for soils, crop coefficients, rooting depths, seepage, etc. that influence crop water balance. It provides spatial soil and climate information and it uses historical crop and land-use category information to provide seasonal water balance estimates by combinations of detailed analysis unit and county (DAU/County) over Califomia. The result is a large data base of ETc and ETaw that will be used to update information in the new California Water Plan (CWP). The application uses the daily climate data, i.e., maximum (Tx) and minimum (Tn) temperature and precipitation (Pcp), which were derived from monthly USDA-NRCS PRISM data (PRISM Group 2011) and daily US National Climate Data Center (NCDC) climate station data to cover California on a 4 kmx4 km change grid spacing. The application uses daily weather data to determine reference evapotranspiration (ETo), using the Hargreaves-Samani (HS) equation (Hargreaves and Samani 1982, 1985). Because the HS equation is based on temperature only, ETo from the HS equation were compared with CIMIS ETo at the same locations using available CIMIS data to determine correction factors to estimate CIMIS ETo from the HS ETo to account for spatial climate differences. CaI-SIMETAW also employs near real-time reference evapotranspiration (ETo) information from Spatial CIMIS, which is a model that combines weather station data and remote sensing to provide a grid of ETo information. A second database containing the available soil water holding capacity and soil depth information for all of California was also developed from the USDA-NRCS SSURGO database. The Cal-SIMETAW program also has the ability to generate daily weather data from monthly mean values for use in studying climate change scenarios and their possible impacts on water demand in the state. The key objective of this project is to improve the accuracy of water use estimates for the California Water Plan (CWP), which provides a comprehensive report on water supply, demand, and management in California. In this paper, we will discuss the model and how it determines ETaw for use in water resources planning.
文摘High temperature and humidity can be controlled in greenhouses by using mechanical refrigeration cooling system such as air conditioner(AC)in warm and humid regions.This study aims to evaluate the techno-financial aspects of the AC-cooled greenhouse as compared to the evaporative cooled(EV-cooled)greenhouse in winter and summer seasons.Two quonset single-span prototype greenhouses were built in the Agriculture Experiment Station of Sultan Qaboos University,Oman,with dimensions of 6.0 m long and 3.0 m wide.The AC-cooled greenhouse was covered by a rockwool insulated polyethylene plastic sheet and light emitting diodes(LED)lights were used as a source of light,while the EV-cooled greenhouse was covered by a transparent polyethylene sheet and sunlight was used as light source.Three cultivars of high-value lettuce were grown for experimentation.To evaluate the technical efficiency of greenhouse performance,we conducted measures on land use efficiency(LUE),water use efficiency(WUE),gross water use efficiency(GWUE)and energy use efficiency(EUE).Financial analysis was conducted to compare the profitability of both greenhouses.The results showed that the LUE in winter were 10.10 and 14.50 kg/m^(2) for the AC-and EV-cooled greenhouses,respectively.However,the values reduced near to 6.80 kg/m^(2) in both greenhouses in summer.The WUE of the AC-cooled greenhouse was higher than that of the EV-cooled greenhouse by 3.8%in winter and 26.8%in summer.The GWUE was used to measure the total yield to the total greenhouse water consumption including irrigation and cooling water;it was higher in the AC-cooled greenhouse than in the EV-cooled greenhouse in both summer and winter seasons by almost 98.0%–99.4%.The EUE in the EV-cooled greenhouse was higher in both seasons.Financial analysis showed that in winter,gross return,net return and benefit-to-cost ratio were better in the EVcooled greenhouse,while in summer,those were higher in the AC-cooled greenhouse.The values of internal rate of return in the AC-and EV-cooled greenhouses were 63.4%and 129.3%,respectively.In both greenhouses,lettuce investment was highly sensitive to changes in price,yield and energy cost.The financial performance of the AC-cooled greenhouse in summer was better than that of the EV-cooled greenhouse and the pattern was opposite in winter.Finally,more studies on the optimum LED light intensity for any particular crop have to be conducted over different growing seasons in order to enhance the yield quantity and quality of crop.
基金This work was supported by the David and Lucie Packard Foundation in partnership with the Energy Foundation, US. Project (G - 0205 -06347)
文摘The Chinese government is developing biomass ethanol as one of its automobile fuels for energy security and environmental improvement reasons. The energy efficiency of the biomass-based fuel ethanol is critical issue. To investigate the energy use in the three biomass-base ethanol fuel systems, energy content approach, Market value approach and Product displacement approach methods were used to allocate the energy use based on life cycle energy assessment. The results shows that the net energy of corn based, wheat based, and cassava-based ethanol fuel are 12543MJ, 10299MJ and 13112MJ when get one ton biomassbased ethanol, respectively, and they do produce positive net energy.
文摘This article discusses cnergy-ficicnt rtfitting design strategics for commercial office buildings,and cxamincs thcir ffect on energy consumption.The objective of the rescarch was to study how to intcgrate passive design stratcgics and cnergy-efficient building systems to improve building performancc,and reduce the cncrgy consumption of existing buildings in three different climate types(cold,mixed and hot climates).First,propertics of existing buildings were analyzed based on national CBECS database to detcrminc typical charactcristics of office buildings located in Chicago,Baltimore and Phoenix,including size,building envelope treatment and building systems.Then,fourteen diffrent prototypes were developed,varying the building shape and orientation to represent different building stock,and cncrgy modcling was conducted to cstablish energy usage baselinc.Multiplc design con-sidcrations were investigated bascd on cxtensivc cncrgy simulations and modeling;where low-impact and decp retrofits were considered.Low-impact stratcgics included improvements to the building cnvelope,lighting systems and optimization of HVAC systems opcration(without upgrading heating and cooling cquipment).Decp cnergy rctrofits also included improvements to building envclopc and lighting,and con-sidered changcs and improvements to HVAC systems(spccifically,integration of radiant systcms).Energy modeling was conducted for all prototypes,and results were obtained for the bascline(current energy usagc),and energy usage considering low-impact design stratcgics and decp rctrofts.A total of 126 cnergy modcls was devcloped,simulated and analyzed,providing a dataset that captured cnergy usage for investigated scenarios.The comparative analysis of simulation results was used to determine how specific techniqucs lead to energy savings in different climatc types,as well as for buildings of various shapes and oricntations.
基金supported by National Natural Science Foundation of China [grant numbers 42371194]。
文摘Developing a green economy is key to achieving the 2030 Sustainable Development Goals. This paper uses the SBM-GML index, which includes non-desired outputs, to measure the trend of regional green economic efficiency changes and analyze the impact mechanism and realization path of industrial transformation on green economic efficiency. The research results show that advanced industrial structure has a positive influence on green economic efficiency nationwide, while energy utilization structure and energy utilization efficiency have positive partial intermediary effects in the influence path;industrial structure rationalization is also significantly positively related to green economic efficiency nationwide, and the mediating effect of energy utilization is positive. The impact of industrial transformation on green economic efficiency has regional heterogeneity, and the mediating effect of energy use also differs. Among them, the impact effect in the eastern region is basically consistent with the national sample, but is negative in the central and western regions. This paper proposes countermeasures in terms of adjusting the industrial structure, improving energy efficiency, and perfecting industrial and energy policies, which can provide theoretical and practical references for promoting the transformation and upgrading of regional industrial structure, optimizing energy utilization, and advancing the efficiency of the national and regional green economy.
基金funded by the National Natural Science Foundation of China(52378109)Shaanxi Provincial Department of Science and Technology(2023KJXX-043).
文摘The“average occupant”methodology is widely used in energy consumption simulations of residential buildings;however,it fails to consider the differences in energy use behavior among family members.Based on a field survey on the Central Shaanxi Plain,to identify the energy use behavior patterns of typical families,a stochastic energy use behavior model considering differences in energy use behavior among family members was proposed,to improve the accuracy of energy consumption simulations of residential buildings.The results indicated that the surveyed rural families could be classified into the following four types depending on specific energy use behavior patterns:families of one elderly couple,families of one middle-aged couple,families of one elderly couple and one child,and families of one couple and one child.Moreover,on typical summer days,the results of daily building energy consumption simulation obtained by the“average occupant”methodology were 25.39%and 28%lower than the simulation results obtained by the model proposed in this study for families of one elderly couple and families of one middle-aged couple,and 13.05%and 23.05%higher for families of one elderly couple and one child,and families of one couple and one child.On typical winter days,for the four types of families,the results of daily building energy consumption simulation obtained by the“average occupant”methodology were 21.69%,10.84%,1.21%,and 8.39%lower than the simulation results obtained by the model proposed in this study,respectively.
基金Item Sponsored by the Fundamental Research Funds for the Central Universities of China(N090602007)
文摘As the largest energy consuming manufacturing sector and one of the most important sources of carhon dioxide (CO2) emissions, the China's iron and steel industry has paid attention to the study of changing trend and influencing factors of CO2 emissions from energy use. The logarithmic mean Divisia index (LMD1) technique is used to decompose total change in CO2 emissions into four factors: emission factor effect, energy structure effect, energy consumption effect, and steel production effect. The results show that the steel production effect is the major factor which is responsible for the rise in CO2 emissions; whereas the energy consumption effect contributes most to the reduction in CO2 emissions. And the emission factor effect makes a weak negative contribution to the increase of CO2 emis- sions. To find out the detailed relationship between change in energy consumption or steel production and change in CO2 emissions, the correlation equations are also proposed.
基金This work was supported by the National Key Research and Development Program of China(2017YFB0403901)This manuscript was presented at 2019 International Symposium on Environment Control Technology for Value-added Plant Production hold in Beijing from Aug.27-29,2019.
文摘Red plus blue light-emitting diodes(LEDs)are commonly applied in plant factories with artificial lighting due to photosynthetic pigments,which absorb strongly in red and blue light regions of the spectrum.However,plants grown under natural environment are used to utilizing broad-wide spectrum by long-term evolution.In order to examine the effects of addition light added in red plus blue LEDs or white LEDs,green and purple leaf lettuces(Lactuca sativa L.cv.Lvdie and Ziya)were hydroponically cultivated for 20 days under white LEDs,white plus red LEDs,red plus blue LEDs,and red plus blue LEDs supplemented with ultraviolet,green or far-red light,respectively.The results indicated that the addition of far-red light in red plus blue LEDs increased leaf fresh and dry weights of green leaf lettuce by 28%and 34%,respectively.Addition of ultraviolet light did not induce any differences in growth and energy use efficiency in both lettuce cultivars,while supplementing green light with red plus blue LEDs reduced the vitamin C content of green leaf lettuce by 44%and anthocyanin content of purple leaf lettuce by 30%compared with red plus blue LEDs,respectively.Spectral absorbencies of purple leaf lettuce grown under red plus blue LEDs supplemented with green light were lower in green light region compared with those grown under red plus blue LEDs,which was associated with anthocyanin contents.White plus red LEDs significantly increased leaf fresh and dry weights of purple leaf lettuce by 25%,and no significant differences were observed in vitamin C and nitrate contents compared with white LEDs.Fresh weight,light and electrical energy use efficiencies of hydroponic green and purple leaf lettuces grown under white plus red LEDs were higher or no significant differences compared with those grown under red plus blue LEDs.In conclusion,white plus red LEDs were suggested to substitute for red plus blue LEDs in hydroponic lettuce(cv.Lvdie and Ziya)production in plant factories with artificial lighting.
文摘The aim of this research is to conduct an energy use efficiency and greenhouse gas(GHG)emission analysis in watermelon production that took place in Kırklareli Province of Turkey during the 2021 production season.This research contains calculations of Energy use efficiency,specific energy,energy productivity and net energy,energy input types,GHG emissions and GHG ratio.Survey,observation and data calculations are related to the 2021 production season.The data used in the research were collected from 30 different(accessible)farms through face-to-face surveys with full count method.EI and EO were calculated as 15698.99 MJ/hm^(2)and 104784.91 MJ/hm^(2),respectively.In relation to production inputs,24.29%of the energy inputs consisted of chemical fertilizers energy(3813.34 MJ/hm^(2)),20.04%consisted of transportation energy(3146.19 MJ/hm^(2)),10.63%consisted of diesel fuel energy(1668.52 MJ/hm^(2)),7.44%consisted of human labour energy(1168.09 MJ/hm^(2)),6.50%consisted of plant energy(1021.02 MJ/hm^(2)),5.76%consisted of electricity energy(904.50 MJ/hm^(2)),5.18%consisted of machinery energy(813.44 MJ/hm^(2)),3.36%consisted of irrigation water energy(527.63 MJ/hm^(2)),2.85%consisted of organic fertilizer energy(446.72 MJ/hm^(2)),2.40%consisted of farmyard manure energy(376.62 MJ/hm^(2))and 0.67%consisted of chemicals energy(105.67 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy were calculated as 6.67,0.28 MJ/kg,3.51 kg/MJ and 89085.91 MJ/hm^(2),respectively.The utilized total energy input in production was grouped as 27.19%direct energy,72.81%indirect energy,22.55%renewable energy and 77.45%nonrenewable.Total GHG emissions and GHG ratio were determined as 492.82 kg CO_(2)-eq/hm^(2),0.01 kg CO_(2)-eq/kg,respectively.
文摘This study has been conducted with the purpose of determining energy use efficiency and greenhouse gas emissions of garlic cultivation during the 2020-2021 cultivation season in Adıyaman province of Turkey.Questionnaires,observations and field works were performed in 134 garlic farms in the region through simple random method.In garlic cultivation,energy input was calculated as 32103.20 MJ/hm^(2)and energy output was calculated as 30096 MJ/hm^(2).With regards to the three highest inputs in garlic production,46.66%of the energy inputs consisted of chemical fertilizers energy(14979.26 MJ/hm^(2)),11.29%consisted of farmyard manure energy(3625.71 MJ/hm^(2))and 10.48%consisted of human labour energy(3363.36 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy in garlic cultivation were calculated as 0.94,1.71 MJ/kg,0.59 kg/MJ,and−2007.20 MJ/hm^(2),respectively.The total energy input consumed in garlic cultivation was classified as 27.19%direct energy,72.81%indirect energy,35.17%renewable energy and 64.87%nonrenewable energy.Total GHG emissions and GHG ratio were calculated as 8636.60 kg CO_(2)-eq/hm^(2)and 0.46 kg CO_(2)-eq/kg,respectively.
基金This work was financially supported by the Key Research and Development Project of Shandong Province(Grant No.2022 CXGC020708)Chinese Universities Scientific Fund(2023TC087).
文摘To enhance the transplants’growth and reduce energy use efficiency,Eggplant(Solanum melongena L.)transplants(cv.Jingqie 21)were cultivated in a plant factory laboratory under different LED light spectrums.The experimental treatments included white plus blue LED lights(R:B=0.5,WB0.5),white LED lights(R:B=0.9,W0.9),white plus red LED lights(R:B=2.7,WR2.7),white plus red plus UV lights(R:B=3.8,WRUV3.8),and red plus blue plus green LED lights(R:B=5.4,RBG5.4).The transplants were grown for 30 d under a light intensity of 250μmol/m2·s and a photoperiod of 16 h/d.The morphological indicators and biomass accumulation of eggplant transplants were significantly higher in the W0.9 treatment compared to the other experimental treatments.The photosynthetic quantum yield in the W0.9 treatment exhibited an increase of over 22%compared to that in the WR2.7 treatment.The shoot dry weight of the W0.9 treatment reached(381±41)mg/plant and the leaf area was(113.3±8.9)cm^(2),indicating a higher health index compared to the other treatments.However,there were no significant differences in the net photosynthetic rate of the leaves among all treatments.The energy yield(EY)of the W0.9 treatment was(37.7±1.8)g/kW·h,which was higher than others.Therefore,considering the high quality of transplants and the maximization of energy use efficiency,the LED light spectrum in the eggplant transplants production was recommended to the white LED light with an R:B ratio of 0.9.
基金National Natural Science Foundation of China(NSFC)German Science Foundation(DFG)Sino-German Science Center
文摘(Quoted from the 1Announcement and Call for Papers) The workshop is aimed at encouraging the use of biomass forenergy production and sustainable development, in particular, inthe field of China’s energy supply. In order to develop a sustain-able (economic, environmentally friendly and sound for futuregenerations) energy supply, pollution caused by emissions duringenergy generation needs to be reduced, and existing resources
文摘The purpose of this study was to determine the energy use efficiency and greenhouse gas(GHG)emissions in peach production that took place in Kırklareli province of Turkey during the 2020-2021 production season.This study included calculations of energy input,energy output,energy use efficiency,specific energy,energy productivity,net energy,energy input types,GHG emissions and GHG ratio.Survey,observation and data calculations are related to the 2020-2021 production season.The data obtained from the study were collected from 16 different farms(reachable)through face-to-face surveys with full count method.Energy input and energy output were calculated as 19570.58 MJ/hm^(2) and 19471.94 MJ/hm^(2),respectively.With regards to production inputs,55.70% of the energy inputs consisted of chemical fertilizers energy(10900.03 MJ/hm^(2)),9.46% consisted of chemicals energy(1852.10 MJ/hm^(2)),9.32% consisted of human labour energy(1823.13 MJ/hm^(2)),7.65% consisted of electricity energy(1497.28 MJ/hm^(2)),6.91% consisted of diesel fuel energy(1351.52 MJ/hm^(2)),4.73% consisted of irrigation water energy(926.10 MJ/hm^(2)),3.43% consisted of machinery energy(671.98 MJ/hm^(2)),1.88% consisted of transportation energy(367.72 MJ/hm^(2)),0.88% consisted of farmyard manure energy(171.80 MJ/hm^(2))and 0.05%consisted of lime energy(8.94 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy were calculated as 0.99,1.91 MJ/kg,0.52 kg/MJ and-98.64 MJ/hm^(2),respectively.The consumed total energy input in production was classified as 28.60% direct energy,71.40% indirect energy,14.93% renewable energy and 85.07% non-renewable.Total GHG emissions and GHG ratio were calculated as 1683.24 kgCO_(2)-eq/hm^(2) and 0.16 kg CO_(2)-eq/kg,respectively.
文摘The energy use of Bitcoin is fiercely debated among academics,practitioners,and the general public.This debate is often biased and characterized by a lack of understanding.Therefore,I start this paper with a discussion of the fundamentals of Bitcoin,which includes the clarification of widely held misconceptions.Next,I illustrate how Bitcoin is related to energy and describe the underlying incentive mechanism.In the main body of the paper,I discuss various components of Bitcoin’s energy use,including the amount,composition,and geographical distribution of the energy,as well as emerging positive and negative effects.These components are then combined into a comprehensive framework that provides a solid foundation for future academic research and presents practitioners with the big picture of how and why Bitcoin requires energy and whether this can be justified from an environmental point of view.
文摘During metal machining, the satisfactoriness of cost-quality-time matrix convergence effectively depends on the supreme selection of cutting parameters. This study investigated the energy use minimisation and quality surface generation through optimised cutting parameters application, as sustainability enhancement during dry turning of EN19 material. Cutting parameter optimisation is a serious challenge confronting the machining industry as they strive to achieve low energy use and better component quality generation from their operations. The utility material, EN19, is a medium-carbon low alloy steel which typically gets applied in the manufacturing of multiple profiled cylindrical machine tool, rail locomotives and motor vehicle component parts, inter alia. Taguchi Full Factorial experimental plan was used to organise the empirical experiments. ANOVA and the main effects plot signal-to-noise ratio optimisation analysis were utilised in the study to establish the influence of process parameters on the response parameters—surface roughness and energy use. The aim was to investigate and determine the correlation of the machining strategy parameters with the outcome of low energy use and quality surface texture of the components as the cutting parameters were varied, and optimised for minimum surface roughness and energy use. Results of the extensive experimental study, produced optimum cutting speed, rake angle variation and feed rate which respectively influence the response parameters positively for energy use minimisation and improved surface quality. Validation experiments confirmed model findings.
文摘Energy used for industrial production, buildings and transport will be accumulated in Atmosphere and Earth land. Global use of energy is known and documented for a long period of time and proportion of fossil and renewable energy is also known. Calculated accumulated energy in Earth land from 1971 to 2018 corresponds to 40% of IPCC Global Energy Inventory and calculated Atmosphere temperature increase from 1971 to 2018 corresponds to 100% of actual measurements.
文摘Consider the task of tracking the energy use of an entire city while also working to reduce it by 50%in 17 years.How would you go about tracking and verifying such reductions?Further,how would this be accomplished in a city without a database of building-specific characteristics and no energy reporting law?To begin,let’s consider what this task would look like for one building.Where to start?Let’s try with a performance metric and point of comparison.Just as cars gauge performance by MPG,and pitchers by ERA,buildings can use Energy Use Intensity(EUI)as a performance metric.Measured in Energy/ft2/year,EUI standardizes energy use per square foot,allowing for comparison between many buildings.EUI is a snapshot of building performance over one year’s time.It is relatively easy to calculate a building’s EUI if their energy usage is known,but in order to gauge performance over a longer period,a constant comparison point must be established so that evaluation is consistent.Called the baseline,this comparison point can be established as a past year,a future goal,or the average performance of similar buildings.This paper covers the work of the Pittsburgh 2030 District team in formulating an energy performance baseline for each building in Downtown Pittsburgh for purposes of tracking energy use reduction towards the 50%reduction goals of The 2030 Challenge.Pittsburgh is a city with a large stock of aging buildings,without mandatory benchmarking laws,and no single publicly accessible real estate profile by property.Thus,the energy baseline methods included in this paper summarize efforts to create such an aggregated property characteristic database and associated energy baseline for Downtown Pittsburgh;it is the hope of the authors that these efforts will assist similar cities in mirroring 2030 District goal setting and achievement for building energy.
基金co-sponsored by the National Natural Science Foundation of China (71774095, 71690244 and 71673165)the Postdoctoral Science Foundation of China (2017M610096)the International Science and Technology Cooperation Program of China (2016YFE0102200)
文摘This study develops a bottom-up model to quantitatively assess the comprehensive effects of replacing traditional petroleum-powered vehicles with natural gas vehicles(NGVs) in China based on an investigation of the direct energy consumption and critical air pollutant(CAP) emission intensity, life-cycle energy use and greenhouse gas(GHG) emission intensity of NGV fleets. The results indicate that, on average, there are no net energy savings from replacing a traditional fuel vehicle with an NGV. Interestingly, an NGV results in significant reductions in direct CAP and life-cycle GHG emissions compared to those of a traditional fuel vehicle, ranging from 61% to 76% and 12% to 29%, respectively. Due to the increasing use of natural gas as a vehicle fuel in China(i.e. approximately 28.2 billion cubic metres of natural gas in2015), the total petroleum substituted with natural gas was approximately 23.8 million tonnes(Mt), which generated a GHG emission reduction of 16.9 Mt of CO2 equivalent and a CAP emission reduction of 1.8 Mt in 2015. Given the significant contribution of NGVs, growing the NGV population in 2020 will further increase the petroleum substitution benefits and CAP and GHG emission reduction benefits by approximately 42.5 Mt of petroleum-based fuel, 3.1 Mt of CAPs and 28.0 Mt of GHGs. By 2030, these benefits will reach 81.5 Mt of traditional petroleum fuel, 5.6 Mt of CAPs and 50.5 Mt of GHGs, respectively.
基金Project(2011BAJ01B05) supported by the National Science and Technology Pillar Program during the Twelfth Five-year Plan Period of China
文摘With rapid economy growth,building energy consumption in China has been gradually increased.The energy consumption and indoor environmental quality of 51 office buildings in Hainan Province,a hot and humid area,were studied through collection of verified data in site visits and field tests.The result revealed that,electricity accounted for 99.79% of the total energy consumption,natural gas 0.17%,and diesel 0.04%.The air conditioning dominated the energy use with a share of 43.18%,equipment in the particular areas 26.90%,equipment in the office rooms 11.95%,lighting system 8.67%,general service system 7.57%,and miscellaneous items 1.73%.Statistical method including six indicators obtained the energy consumption benchmark with upper limit of 98.31 kW-h/m2 and lower limit of 55.26 kW-h/m2.According to ASHRAE standard(comfortable standard) and GB/T 18883-2002(acceptable standard),the indoor environmental quality of 51 sampled office buildings was classified into three ranks:good,normal and bad.With benchmark of building energy consumption combined with indoor environmental quality,it was found that only 3.92% of sampled buildings can be identified as the best performance buildings with low energy consumption and advanced indoor environmental quality,and the buildings classified into normal level accounted for the maximum ratio.