The studies and development of coal seam gas（CSG） have been conducted for more than 30 years in China, but few of China＇s CSG projects have achieved large-scale commercial success; faced with the boom of shale gas,...The studies and development of coal seam gas（CSG） have been conducted for more than 30 years in China, but few of China＇s CSG projects have achieved large-scale commercial success; faced with the boom of shale gas, some investors are beginning to lose patience and confidence in CSG. China currently faces the following question： Should the government continue to vigorously support the development of the CSG industry？ To provide a reference for policy makers and investors, this paper calculates the EROI_（stnd）[a standardized energy return on investment（EROI） method], EROI_（ide）（the maximum theoretical EROI）, EROI_（3,i）（EROI considering the energy investment in transport）, and EROI_（3,1＋e）（EROI with environmental inputs） of a single vertical CSG well in the Fanzhuang CSG project in the Qinshui Basin. The energy payback time（EPT） and the greenhouse gas（GHG） emissions of the CSG systems are also calculated. The results show that over a 15-year lifetime, EROI_（stnd）, EROI_（ide）, EROI_（3,1）, and EROI_（3,1＋e）are expected to deliver EROIs of approximately11：1, 20：1, 7：1, and 6：1, respectively. The EPT within different boundaries is no more than 2 years, and the life-cycle GHG emissions are approximately 18.8 million kg CO_2 equivalent. The relatively high EROI and short EPT indicate that the government should take more positive measures to promote the development of the CSG industry.展开更多
The index of payback period of dynamic investment is an improvement on index of payback period of static investment, which is the problem that the rules to evaluate the project are feasible or not. This paper proves t...The index of payback period of dynamic investment is an improvement on index of payback period of static investment, which is the problem that the rules to evaluate the project are feasible or not. This paper proves that rules shall be apt when using payback period of dynamic investment to evaluate the project feasibility under the condition of keeping the dynamic evaluation index to evaluate the same scheme and the consistent feasibility.展开更多
Ecological payback time was calculated for demolishing an existing commercial building with average energy performance and replacing it with an energy-efficient,prefabricated building.A life-cycle assessment was perfo...Ecological payback time was calculated for demolishing an existing commercial building with average energy performance and replacing it with an energy-efficient,prefabricated building.A life-cycle assessment was performed for a 5,000 ft2 commercial building designed by Project Frog and prefabricated in San Francisco,California,and compared to the impacts of annual energy consumption and continued status quo operation of a comparable average commercial building.Scenarios were run both with and without rooftop solar panels intended to make the prefabricated building net zero energy.The analysis considers the materials and manufacturing,transportation,annual energy use of the new building,and disposal of the existing building,compared to continued annual energy use of the existing building.The carbon payback of a new building with no solar against operation of an existing commercial building was found to be roughly eleven years,and a building with enough rooftop solar to be net zero energy was roughly 6.5 years.The full EcoIndicator99 environmental impact payback for a new efficient building with no solar was found to be twenty years,and a solar net-zero building was roughly eleven years against operation of an existing commercial building.展开更多
基金supported by the National Natural Science Foundation of China (No. 71273277, 71722003, 71690244)the Philosophy and Social Sciences Major Research Project of the Ministry of Education (No. 11JZD048)the National Key R&D Program (2016YFC0208901)
文摘The studies and development of coal seam gas（CSG） have been conducted for more than 30 years in China, but few of China＇s CSG projects have achieved large-scale commercial success; faced with the boom of shale gas, some investors are beginning to lose patience and confidence in CSG. China currently faces the following question： Should the government continue to vigorously support the development of the CSG industry？ To provide a reference for policy makers and investors, this paper calculates the EROI_（stnd）[a standardized energy return on investment（EROI） method], EROI_（ide）（the maximum theoretical EROI）, EROI_（3,i）（EROI considering the energy investment in transport）, and EROI_（3,1＋e）（EROI with environmental inputs） of a single vertical CSG well in the Fanzhuang CSG project in the Qinshui Basin. The energy payback time（EPT） and the greenhouse gas（GHG） emissions of the CSG systems are also calculated. The results show that over a 15-year lifetime, EROI_（stnd）, EROI_（ide）, EROI_（3,1）, and EROI_（3,1＋e）are expected to deliver EROIs of approximately11：1, 20：1, 7：1, and 6：1, respectively. The EPT within different boundaries is no more than 2 years, and the life-cycle GHG emissions are approximately 18.8 million kg CO_2 equivalent. The relatively high EROI and short EPT indicate that the government should take more positive measures to promote the development of the CSG industry.
基金This paper is supported by the National Natural Science Foundation of China （No.59579029）
文摘The index of payback period of dynamic investment is an improvement on index of payback period of static investment, which is the problem that the rules to evaluate the project are feasible or not. This paper proves that rules shall be apt when using payback period of dynamic investment to evaluate the project feasibility under the condition of keeping the dynamic evaluation index to evaluate the same scheme and the consistent feasibility.
文摘July 1st,an important day to mark summer arrival not according to Chinese lunar calendar,but to the habitual way of thinking that hot season sets in.
文摘Ecological payback time was calculated for demolishing an existing commercial building with average energy performance and replacing it with an energy-efficient,prefabricated building.A life-cycle assessment was performed for a 5,000 ft2 commercial building designed by Project Frog and prefabricated in San Francisco,California,and compared to the impacts of annual energy consumption and continued status quo operation of a comparable average commercial building.Scenarios were run both with and without rooftop solar panels intended to make the prefabricated building net zero energy.The analysis considers the materials and manufacturing,transportation,annual energy use of the new building,and disposal of the existing building,compared to continued annual energy use of the existing building.The carbon payback of a new building with no solar against operation of an existing commercial building was found to be roughly eleven years,and a building with enough rooftop solar to be net zero energy was roughly 6.5 years.The full EcoIndicator99 environmental impact payback for a new efficient building with no solar was found to be twenty years,and a solar net-zero building was roughly eleven years against operation of an existing commercial building.
