Thermophotovoltaic （TPV） system has been regarded as one promising means to alleviate current energy demand because it can directly generate electricity from radiation heat via photons. However, the presently availa...Thermophotovoltaic （TPV） system has been regarded as one promising means to alleviate current energy demand because it can directly generate electricity from radiation heat via photons. However, the presently available TPV systems suffer from low conversion efficiency and low throughput. A viable solution to increase their efficiency is to apply micro/nanoscale radiation principles in the design of different components to utilize the characteristics ~f thermal radiation at small distances and in microstructures. Several critical issues are reviewed, such as photovoltaic effect, quantum efficiency and efficiency of TPV system. Emphasis is given to the development of wavelength-selective emitters and filters and the aspects of micro/nanoscale heat transfer. Recent progress, along with the challenges and opportunities for future development of TPV systems are also outlined.展开更多
The objective of the present paper is to describe a technical and economical visibility study of the application of ground source heat pumps （GSHP） in a supermarket in Portugal. The study was developed under the Eur...The objective of the present paper is to describe a technical and economical visibility study of the application of ground source heat pumps （GSHP） in a supermarket in Portugal. The study was developed under the European project ＂Integration of Geothermal Energy Into Industrial Application - IGEIA＂, project number EIE 06/001, supported by the Intelligent Energy for Europe, IEE, of EACI, European Commission. In general for supermarkets installed in single buildings, the building envelope has higher rates of envelope areas per indoor air volume. In Portugal this fact produces high need of heating during the winter season and high cooling needs during the summer season. Inside the building there are strong internal heat loads produced by high densities of lights and equipments. However these internal loads are not distributed uniformly. There are some areas with high production of heat but there are others with production of cooling. Therefore the acclimatization of this kind of buildings is not so easy and the balance of heating and cooling needs is depending of different parameters which should be well evaluated. The energy consummation of the cold display cases and deep freezers in market area and storage is also very high. The different energy needs could be studied in an integrated way and could be partially satisfied by geothermal energy using ground source heat pumps. At the same time the boreholes could be used as an energy reservoir increasing the efficiency of whole system. Four different climatic zones in Portugal were selected, （north coast, interior north, south coast and interior south） using the same system. The results of the study show that the all energy needs can by partially satisfied by geothermal energy but they need to be integrated to increase the global efficiency. The paper shows that the geothermal energy can be an attractive application for the supermarkets in Portugal if the energy solution is studied in an integrated way and if it is also considered as a cost the emissions of CO2 avoid by the new system.展开更多
The sustainable and rapid development of Chinese economy entails fast growth of energy demand. In recent years, power is in short supply： supply and transportation of coal is tense causing a price rise; crude oil imp...The sustainable and rapid development of Chinese economy entails fast growth of energy demand. In recent years, power is in short supply： supply and transportation of coal is tense causing a price rise; crude oil import increases and oil price lingers on high end. These phenomena reflccting energy shortage have become people＇hot-debated issues in economic life, and public economic regulators and economists have shown unprecedented concerns about the energy-, environment-, and resources-related issues from the sustainable development point of view.展开更多
The periodic character of economic development and energy demand, the basic national policy of saving energy and reducing emissions, and the constraints of curbing global warming and reducing greenhouse gas emissions ...The periodic character of economic development and energy demand, the basic national policy of saving energy and reducing emissions, and the constraints of curbing global warming and reducing greenhouse gas emissions all necessitate corresponding adjustments to China＇s energy strategy, and especially its energy structure strategy. The previous energy strategy focused primarily on energy reserves and production, i.e., focused on energy supply in order to meet energy demand. In response to global climate change, the readjustment of China＇s energy strategy has become imperative： on the one hand, the government needs to engage in serious management of both energy supply and energy demand to meet China＇s energy demand; on the other, it needs to reduce CO： emissions and make this a constraint on meeting energy demand. In our study, through establishing an optimal model, we get the optimal energy structure allowing for energy conservation and emission constraints; then we proceed, by means of a computable general equilibrium （CGE） model, to estimate the impact of rising energy costs as a result of changes in energy structure on the macro-economy. Our research results show that the government＇s plan for renewable energy has a positive impact on reducing CO2 emissions. However, rising energy costs as a result of changes in the energy structure under carbon emission constraints negatively affects macro-economic performance. As many important Chinese industries depend heavily on coal and thermoelectricity, the room for CO2 emission reductions is limited at the present stage. Instead, the government should pay attention to realizing CO2 emission reductions in other fields of economic life.展开更多
基金Project(2009AA05Z215) supported by the National High Technology Research and Development Program of China
文摘Thermophotovoltaic （TPV） system has been regarded as one promising means to alleviate current energy demand because it can directly generate electricity from radiation heat via photons. However, the presently available TPV systems suffer from low conversion efficiency and low throughput. A viable solution to increase their efficiency is to apply micro/nanoscale radiation principles in the design of different components to utilize the characteristics ~f thermal radiation at small distances and in microstructures. Several critical issues are reviewed, such as photovoltaic effect, quantum efficiency and efficiency of TPV system. Emphasis is given to the development of wavelength-selective emitters and filters and the aspects of micro/nanoscale heat transfer. Recent progress, along with the challenges and opportunities for future development of TPV systems are also outlined.
文摘The objective of the present paper is to describe a technical and economical visibility study of the application of ground source heat pumps （GSHP） in a supermarket in Portugal. The study was developed under the European project ＂Integration of Geothermal Energy Into Industrial Application - IGEIA＂, project number EIE 06/001, supported by the Intelligent Energy for Europe, IEE, of EACI, European Commission. In general for supermarkets installed in single buildings, the building envelope has higher rates of envelope areas per indoor air volume. In Portugal this fact produces high need of heating during the winter season and high cooling needs during the summer season. Inside the building there are strong internal heat loads produced by high densities of lights and equipments. However these internal loads are not distributed uniformly. There are some areas with high production of heat but there are others with production of cooling. Therefore the acclimatization of this kind of buildings is not so easy and the balance of heating and cooling needs is depending of different parameters which should be well evaluated. The energy consummation of the cold display cases and deep freezers in market area and storage is also very high. The different energy needs could be studied in an integrated way and could be partially satisfied by geothermal energy using ground source heat pumps. At the same time the boreholes could be used as an energy reservoir increasing the efficiency of whole system. Four different climatic zones in Portugal were selected, （north coast, interior north, south coast and interior south） using the same system. The results of the study show that the all energy needs can by partially satisfied by geothermal energy but they need to be integrated to increase the global efficiency. The paper shows that the geothermal energy can be an attractive application for the supermarkets in Portugal if the energy solution is studied in an integrated way and if it is also considered as a cost the emissions of CO2 avoid by the new system.
文摘The sustainable and rapid development of Chinese economy entails fast growth of energy demand. In recent years, power is in short supply： supply and transportation of coal is tense causing a price rise; crude oil import increases and oil price lingers on high end. These phenomena reflccting energy shortage have become people＇hot-debated issues in economic life, and public economic regulators and economists have shown unprecedented concerns about the energy-, environment-, and resources-related issues from the sustainable development point of view.
文摘The periodic character of economic development and energy demand, the basic national policy of saving energy and reducing emissions, and the constraints of curbing global warming and reducing greenhouse gas emissions all necessitate corresponding adjustments to China＇s energy strategy, and especially its energy structure strategy. The previous energy strategy focused primarily on energy reserves and production, i.e., focused on energy supply in order to meet energy demand. In response to global climate change, the readjustment of China＇s energy strategy has become imperative： on the one hand, the government needs to engage in serious management of both energy supply and energy demand to meet China＇s energy demand; on the other, it needs to reduce CO： emissions and make this a constraint on meeting energy demand. In our study, through establishing an optimal model, we get the optimal energy structure allowing for energy conservation and emission constraints; then we proceed, by means of a computable general equilibrium （CGE） model, to estimate the impact of rising energy costs as a result of changes in energy structure on the macro-economy. Our research results show that the government＇s plan for renewable energy has a positive impact on reducing CO2 emissions. However, rising energy costs as a result of changes in the energy structure under carbon emission constraints negatively affects macro-economic performance. As many important Chinese industries depend heavily on coal and thermoelectricity, the room for CO2 emission reductions is limited at the present stage. Instead, the government should pay attention to realizing CO2 emission reductions in other fields of economic life.
