An improved energy demand forecasting model is built based on the autoregressive distributed lag(ARDL) bounds testing approach and an adaptive genetic algorithm(AGA) to obtain credible energy demand forecasting result...An improved energy demand forecasting model is built based on the autoregressive distributed lag(ARDL) bounds testing approach and an adaptive genetic algorithm(AGA) to obtain credible energy demand forecasting results. The ARDL bounds analysis is first employed to select the appropriate input variables of the energy demand model. After the existence of a cointegration relationship in the model is confirmed, the AGA is then employed to optimize the coefficients of both linear and quadratic forms with gross domestic product, economic structure, urbanization,and technological progress as the input variables. On the basis of historical annual data from1985 to 2015, the simulation results indicate that the proposed model has greater accuracy and reliability than conventional optimization methods. The predicted results of the proposed model also demonstrate that China will demand approximately 4.9, 5.6, and 6.1 billion standard tons of coal equivalent in 2020, 2025, and 2030, respectively.展开更多
Under China’s“Dual Carbon”target(DCT),“clean replacement”on the energy supply side and“electric energy replacement”on the energy consumption side are the ways to achieve energy transformation.However,energy pro...Under China’s“Dual Carbon”target(DCT),“clean replacement”on the energy supply side and“electric energy replacement”on the energy consumption side are the ways to achieve energy transformation.However,energy projects have a long construction period,complex technology categories,and investment risks that greatly affect the development of energy transformation.Correctly judging the effect of investment changes on primary energy production is of great practical significance to the realization of the DCT.Based on this,NARDL and TVP-SV-VAR models are innovatively used to reveal the nonlinear effect of fixed-asset investment on China’s primary energy production.The results show that the marginal effect of investment growth on coal production is about 1.44 times that of investment reduction.Similarly,the marginal effect of oil and gas investment growth is about 1.21times that of investment reduction.Due to the influence of resource constraints,China’s traditional fossil energy still has varying degrees of path dependence on the investment-driven development model.For non-fossil energy,investment in hydropower and nuclear power has an inverse correlation with the change in production.Negative marginal efficiency and diseconomies of scale have hindered the development of the hydropower and nuclear power industries.In addition,the asymmetric effect is not yet significant for the short development time and technical constraints of wind and solar power.From the impulse response results,the impact curves of investment in wind and solar power are generally positive,and investment has different degrees of time-delay and time-varying effects on various energy production,which verifies the heterogeneity of investment adjustment mechanisms in different energy industries.展开更多
In this paper,the primary energy source of high current electron beam accelerator based on spiral pulse forming line is investigated.It consists of the constant-current power supply,the high voltage pulse capacitor,th...In this paper,the primary energy source of high current electron beam accelerator based on spiral pulse forming line is investigated.It consists of the constant-current power supply,the high voltage pulse capacitor,the field distortion switch,and the protection system.The primary energy source can discharge to the primary winding of the transformer with high voltage pulses whose amplitude of voltage is 40kV,current is 80kA,pulse width is 8μs and repetition frequency is less than 5Hz.The primary energy source is applied to a high current electron beam accelerator, and is featured by its compactness,stability and reliability.展开更多
Primary energy has the potential to bring challenges to the reliability,economic,and eco-friendliness of global electric power systems.The concept of electric power security are proposed,including many factors that ar...Primary energy has the potential to bring challenges to the reliability,economic,and eco-friendliness of global electric power systems.The concept of electric power security are proposed,including many factors that are not considered in power system reliability analysis,such as coal supply for power system,fuel price for electricity power market,carbon emissions of power generation,and so on.It is broader than power system reliability and security,which means that providing energy in the form of reliable,economical,and eco-friendly electric power.Following an account of existing blackout defence methods and systems,the processes of transforming various kinds of primary energy into electric power and the interactions between them are described,particularly with regard to flows of energy,capital,and information.Factors that limit the liquidity of these flows are defined as“generalized congestion”,and the challenges presented by primary energy are named“primary energy congestion”.China’s dilemma on coal supply for power generation is presented in some detail as an example of primary energy congestion.To cope with impacts of the primary energy on electric power systems,an idea is introduced to extend the scope of existing coordinated blackout defence systems to account for primary energy,which would lead to an integrated tool to provide decision support to power system operators accounting for primary energy congestion.展开更多
This work reveals the positioning of natural gas in the evolution of world energy and the general law of its development.In the long-term adjustment of energy structure,natural gas has gradually become the primary ene...This work reveals the positioning of natural gas in the evolution of world energy and the general law of its development.In the long-term adjustment of energy structure,natural gas has gradually become the primary energy source because of five factors:policy,resources,technology,facilities,and market.To expedite the revolution of energy production and consumption,China must urgently expand the use of natural gas toward a more positive role in complementing coal and renewable energy and prioritize its usage in three areas,namely,urban gas,power generation,and industrial fuel.Natural gas is expected to account for approximately 15%of China’s total energy consumption in the future.For natural gas to be the primary energy,the exploitation of gas resources must be expanded,resource access must be improved,a flexible trade system must be set up,infrastructure investment must be increased,and the security system must be enhanced.展开更多
In order to evaluate the heating performance of gas engine heat pump(GEHP) for air-conditioning and hot water supply, a test facility was developed and experiments were performed over a wide range of engine speed(1...In order to evaluate the heating performance of gas engine heat pump(GEHP) for air-conditioning and hot water supply, a test facility was developed and experiments were performed over a wide range of engine speed(1400-2600 r/min), ambient air temperature(2.4-17.8 ℃) and condenser water inlet temperature(30-50℃). The results show that as engine speed increases from 1400 r/min to 2600 r/min, the total heating capacity and energy consumption increase by about 30% and 89%, respectively; while the heat pump coefficient of performance(COP) and system primary energy ratio(PER) decrease by 44% and 31%, respectively. With the increase of ambient air temperature from 2.4 ℃ to 17.8 ℃, the heat pump COP and system PER increase by 32% and 19%, respectively. Moreover, the heat pump COP and system PER decrease by 27% and 15%, respectively, when the condenser water inlet temperature changes from 30 ℃ to 50 ℃. So, it is obvious that the effect of engine speed on the performance is more significant than the effects of ambient air temperature and condenser water inlet temperature.展开更多
Energy is one of the most important resources in the economy of developing countries. Jordan depends mainly on imported oil and gas at international prices. This creates a heavy burden upon Jordanian national economy,...Energy is one of the most important resources in the economy of developing countries. Jordan depends mainly on imported oil and gas at international prices. This creates a heavy burden upon Jordanian national economy, which is reflected in the same time on other sectors of the Jordanian society. The ever increasing fuel prices make it very necessary to look for new renewable energy resources. Jordan as a developing country with its fast growing urban development and construction projects will be studied. It is worthy to study the dynamic relationship between end user, fuel and comfort in the residential sector. Energy is a chronic problem in Jordan, due to lack of non renewable energy resources, the end consumer is influenced by this fact, in achieving his basic energy needs. This study tries to shed light on the fuel poverty line, definitions and parameters of fuel poverty. And to study what has been done in this regard on both international and local level. No studies have been identified in Jordan which, explore the problem of fuel poverty, especially after the vast and recent increase in fuel prices internationally and locally. This study will follow theoretical and field survey to understand the relationship between comfort, energy and building fabric. Method will depend mainly on field survey and statistical data, and necessary measurements, questionnaires will be adopted when necessary to explore comfort levels related to fuel consumption. Summary and recommendations will be concerned with how thermal comfort could be achieved within the ranges of fuel accessibility, building fabric, minimum pollution and cost.展开更多
The first available label standardizing a zero-balanced type of building is the Swiss Standard Minergie-A. The standard prescribes an annual net zero primary energy balance for heating, domestic hot water and ventilat...The first available label standardizing a zero-balanced type of building is the Swiss Standard Minergie-A. The standard prescribes an annual net zero primary energy balance for heating, domestic hot water and ventilation. Electricity consumption for appliances and lighting is excluded. Additionally, Minergie-A is the first standard worldwide which includes a requirement in regard to embodied energy. Based on an analysis of 39 Minergie-A buildings, this paper shows that a wide range of different energy concepts and embodied energy strategies are possible in the scope of the label. The basis of all Minergie-A buildings is a well-insulated building envelope. However, the step from the Swiss Standard Minergie-A to a Net ZEB (net zero energy building) standard which includes electricity consumption for appliances and lighting is not a very big one. Increasing the size of the photovoltaic system is sufficient in most cases. Anyway, some of the Minergie-A buildings evaluated are also Net ZEBs. In this paper, it is also shown that the net zero balance during the operational phase of Net ZEBs clearly outweighs the increased embodied energy for additional materials in a life cycle energy analysis.展开更多
There is a high potential for small-scale and medium scale wood-fired cogeneration in Estonia. The purpose of this research is to define the eligible capacity for wood fuel based cogeneration plant operating on the ba...There is a high potential for small-scale and medium scale wood-fired cogeneration in Estonia. The purpose of this research is to define the eligible capacity for wood fuel based cogeneration plant operating on the base of district heating systems in small towns. Results were checked and approbated by economical and environmental factors. Two optimal sizing methods were used maximizing of amount of heat year-round while working at full installed capacity and maximizing of amount of heat year-round while working with partial loads. Results of defining optimal capacities for wood-fired cogeneration plants in small Estonian towns showed that method of maximizing of amount of heat year-round while working with partial loads is more adequate to real situation.展开更多
What needs to be developed from the concept of"Smart Grid"is that:when renewable energy sources are absolutely prevailing in power generation,distributed power generation and distributed energy storage syste...What needs to be developed from the concept of"Smart Grid"is that:when renewable energy sources are absolutely prevailing in power generation,distributed power generation and distributed energy storage systems are widespread across the grid,and electric vehicle charging loads are prevailing in power load demands,how can the power grid support electric power as a core secondary energy source,undertake the role of a bridge between primary energy and end-use energy,and achieve the coordination and the optimization in macro energy perspective;how to guarantee the security of both macro energy and environment as well as the reliability of electricity.If a new term is needed,it should be Comprehensive Energy Network,not Energy Internet.展开更多
Based on the integrated input output accounting system of natural resources and economy, Chinese 1992 Input Output Table and Chinese Statistics Year Book (1993) , one new and concrete Energy Economy Environmental ...Based on the integrated input output accounting system of natural resources and economy, Chinese 1992 Input Output Table and Chinese Statistics Year Book (1993) , one new and concrete Energy Economy Environmental Input Output Table, Chinese 92’Energy Economy Environmental Input Output Table is put forward in this paper, and scenario forecast and analysis of Chinese energy resources economy environmental situation (1992 2020) are given, too.展开更多
To pursue the goal of sustainable mobility,two main paths can be considered:the electrification of vehicles and the use of biofuels,replacing fossil fuels,in internal combustion engine(ICE)vehicles.This paper proposes...To pursue the goal of sustainable mobility,two main paths can be considered:the electrification of vehicles and the use of biofuels,replacing fossil fuels,in internal combustion engine(ICE)vehicles.This paper proposes an analysis of different possible scenarios for automobiles towards a CO_(2)-neutral energy system,in the path of the use of biofuels and the production,distribution and use of biomethane.The study,an update of work presented previously,focuses on different scenarios that take into account numerous parameters that affect the overall efficiency of the production-and-use process.A Well-to-Wheel analysis is used to estimate the primary energy savings and reduction in greenhouse-gas emissions compared both to the use of fossil-based methane and to other fuels and automotive technologies.In particular,the study shows that the Non-Renewable Primary Energy Consumption(NRPEC)for biomethane is slightly higher(+9%)than that of biodiesel,but significantly lower than those of all the other power trains analysed:-69%compared to the battery electric vehicle(BEV)and-55%compared to bioethanol.Compared to the use of fossil natural gas,the NRPEC is reduced to just over a third(2.81).With regard to CO_(2) emissions,biomethane has the lowest values:-69%compared to BEV,-176%compared to bioethanol and-124%with respect to biodiesel.Compared to the use of fossil natural gas,the CO_(2) emissions are reduced over a third(3.55).Moreover,the paper shows that biomethane can completely cover the consumption of fossil methane for vehicles in Italy,proposing two different hypotheses:maximum production and minimum production.It is evident,therefore,that biomethane production can completely cover the consumption of fossil methane for vehicles:this means that the use of biomethane in the car can lead to a reduction in NRPEC equal to 28.9×10^(6) GJ/year and a reduction of CO_(2) emissions equal to 1.9×10^(6) t/year.展开更多
The paper demonstrates how electromagnetic processing of materials(EPM)provides significant opportunities for saving primary energy and reducing carbon emissions in industrial thermal processes.Potentially electricity...The paper demonstrates how electromagnetic processing of materials(EPM)provides significant opportunities for saving primary energy and reducing carbon emissions in industrial thermal processes.Potentially electricity can replace up to 100%of other energy carriers currently used for process heat.For the time horizon from now to the year 2050 a transition scenario is developed and described.In this scenario the industrial processes are gradually switched from the actual situation to a situation with 100%electrically operated industrial processes.The developed scenarios take into account the most energy intensive industrial thermal processes,which could be replaced by electrothermal technologies and offer obviously the biggest future potential in terms of saving of primary energy and reducing of carbon emissions.As the average primary energy factor(PEF)gradually decreases from 2.5 currently,to 1 for a 100%renewable electricity system,the benefits of EPM will gradually increase.For each step in the development of the PEF the annual primary energy savings and annual reductions in greenhouse gas emissions are calculated and described in this paper.展开更多
A floating type pendulum wave energy converter(FPWEC) with a rotary vane pump as the power take-off system was proposed by Watabe et al.in 1998.They showed that this device had high energy conversion efficiency.In the...A floating type pendulum wave energy converter(FPWEC) with a rotary vane pump as the power take-off system was proposed by Watabe et al.in 1998.They showed that this device had high energy conversion efficiency.In the previous research,the authors conducted 2D wave tank tests in regular waves to evaluate the generating efficiency of FPWEC with a power take-off system composed of pulleys,belts and a generator.As a result,the influence of the electrical load on the generating efficiency was shown.Continuously,the load characteristics of FPWEC are pursued experimentally by using the servo motors to change the damping coefficient in this paper.In a later part of this paper,the motions of the model with the servo motors are compared with that of the case with the same power take-off system as the previous research.From the above experiment,it may be concluded that the maximum primary conversion efficiency is achieved as high as 98%at the optimal load.展开更多
Extreme weather events, sea level rise, and political disputes linked to climate change are driving masses to leave their homes. Their transitional settlements should be produced in a manner that causes minimum greenh...Extreme weather events, sea level rise, and political disputes linked to climate change are driving masses to leave their homes. Their transitional settlements should be produced in a manner that causes minimum greenhouse gas(GHG) emissions to prevent any further acceleration of climate change and the humanitarian crises it causes. This article presents a study of the carbon footprint and primary energy demand of the construction materials of eight different transitional shelters. The lowest carbon footprints were found from shelter models made from bamboo or timber. The highest emissions were caused by shelters that have either a short service life or that are made from metal-intensive structures. The choice of cladding materials was surprisingly important. The findings were further compared to the overall impacts of each construction project, to national per capita GHG emissions,and to construction costs. Some shelter projects had notable total energy consumption even compared to the annual energy use of industrialized countries. The study concludes that construction materials have an important impact on the carbon footprint of shelters. Comparisons should however be made only between similar functional units. Furthermore, benchmark values and more background data are urgently needed in order to give humanitarian nongovernmental organizations tools for lowering the carbon footprint of their construction operations.展开更多
With life cycle assessment(LCA) methodology,a life cycle model of coal-based vehicle fuels(CBVFs) including coal-based dimethyl ether(CBDME) and coal-based diesel(CBD) is established.Their primary energy consumption(P...With life cycle assessment(LCA) methodology,a life cycle model of coal-based vehicle fuels(CBVFs) including coal-based dimethyl ether(CBDME) and coal-based diesel(CBD) is established.Their primary energy consumption(PEC) and global warming potential(GWP) from well to wheel including feedstock extraction,fuel production,fuel consumption in vehicle and energy transportation are calculated and compared.Results show that the life cycle PEC and GWP of CBD pathway are 1.17 and 1.34 times as CBDME pathway.Based on the above results,CBDME will become a choice with great potential to replace conventional petroleum-based diesel (CPBD) in China.展开更多
文摘An improved energy demand forecasting model is built based on the autoregressive distributed lag(ARDL) bounds testing approach and an adaptive genetic algorithm(AGA) to obtain credible energy demand forecasting results. The ARDL bounds analysis is first employed to select the appropriate input variables of the energy demand model. After the existence of a cointegration relationship in the model is confirmed, the AGA is then employed to optimize the coefficients of both linear and quadratic forms with gross domestic product, economic structure, urbanization,and technological progress as the input variables. On the basis of historical annual data from1985 to 2015, the simulation results indicate that the proposed model has greater accuracy and reliability than conventional optimization methods. The predicted results of the proposed model also demonstrate that China will demand approximately 4.9, 5.6, and 6.1 billion standard tons of coal equivalent in 2020, 2025, and 2030, respectively.
基金supported by the National Natural Science Foundation of China under Grant No.71874133the Youth Innovation Team of Shaanxi Universities under Grant No.2020-68+1 种基金Shaanxi Province Qin Chuangyuan“Scientist+Engineer”Team Building Project under Grant No.2022KXJ-007the Seed Foundation of Innovation Practice for Graduate Students in Xidian University under Grant No.2021-26。
文摘Under China’s“Dual Carbon”target(DCT),“clean replacement”on the energy supply side and“electric energy replacement”on the energy consumption side are the ways to achieve energy transformation.However,energy projects have a long construction period,complex technology categories,and investment risks that greatly affect the development of energy transformation.Correctly judging the effect of investment changes on primary energy production is of great practical significance to the realization of the DCT.Based on this,NARDL and TVP-SV-VAR models are innovatively used to reveal the nonlinear effect of fixed-asset investment on China’s primary energy production.The results show that the marginal effect of investment growth on coal production is about 1.44 times that of investment reduction.Similarly,the marginal effect of oil and gas investment growth is about 1.21times that of investment reduction.Due to the influence of resource constraints,China’s traditional fossil energy still has varying degrees of path dependence on the investment-driven development model.For non-fossil energy,investment in hydropower and nuclear power has an inverse correlation with the change in production.Negative marginal efficiency and diseconomies of scale have hindered the development of the hydropower and nuclear power industries.In addition,the asymmetric effect is not yet significant for the short development time and technical constraints of wind and solar power.From the impulse response results,the impact curves of investment in wind and solar power are generally positive,and investment has different degrees of time-delay and time-varying effects on various energy production,which verifies the heterogeneity of investment adjustment mechanisms in different energy industries.
文摘In this paper,the primary energy source of high current electron beam accelerator based on spiral pulse forming line is investigated.It consists of the constant-current power supply,the high voltage pulse capacitor,the field distortion switch,and the protection system.The primary energy source can discharge to the primary winding of the transformer with high voltage pulses whose amplitude of voltage is 40kV,current is 80kA,pulse width is 8μs and repetition frequency is less than 5Hz.The primary energy source is applied to a high current electron beam accelerator, and is featured by its compactness,stability and reliability.
基金This work is jointly supported by Major Program of National Natural Science Foundation of China(No.91024028)National High Technology Research and Development Program of China(863 Program)(No.2011AA05A105)+1 种基金SGCC Projects SGCC-MPLG003-2012the Australian Research Council(DP120101345).
文摘Primary energy has the potential to bring challenges to the reliability,economic,and eco-friendliness of global electric power systems.The concept of electric power security are proposed,including many factors that are not considered in power system reliability analysis,such as coal supply for power system,fuel price for electricity power market,carbon emissions of power generation,and so on.It is broader than power system reliability and security,which means that providing energy in the form of reliable,economical,and eco-friendly electric power.Following an account of existing blackout defence methods and systems,the processes of transforming various kinds of primary energy into electric power and the interactions between them are described,particularly with regard to flows of energy,capital,and information.Factors that limit the liquidity of these flows are defined as“generalized congestion”,and the challenges presented by primary energy are named“primary energy congestion”.China’s dilemma on coal supply for power generation is presented in some detail as an example of primary energy congestion.To cope with impacts of the primary energy on electric power systems,an idea is introduced to extend the scope of existing coordinated blackout defence systems to account for primary energy,which would lead to an integrated tool to provide decision support to power system operators accounting for primary energy congestion.
文摘This work reveals the positioning of natural gas in the evolution of world energy and the general law of its development.In the long-term adjustment of energy structure,natural gas has gradually become the primary energy source because of five factors:policy,resources,technology,facilities,and market.To expedite the revolution of energy production and consumption,China must urgently expand the use of natural gas toward a more positive role in complementing coal and renewable energy and prioritize its usage in three areas,namely,urban gas,power generation,and industrial fuel.Natural gas is expected to account for approximately 15%of China’s total energy consumption in the future.For natural gas to be the primary energy,the exploitation of gas resources must be expanded,resource access must be improved,a flexible trade system must be set up,infrastructure investment must be increased,and the security system must be enhanced.
基金Project(hx2013-87)supported by the Qingdao Economic and Technology Development Zone Haier Water-Heater Co.Ltd.,China
文摘In order to evaluate the heating performance of gas engine heat pump(GEHP) for air-conditioning and hot water supply, a test facility was developed and experiments were performed over a wide range of engine speed(1400-2600 r/min), ambient air temperature(2.4-17.8 ℃) and condenser water inlet temperature(30-50℃). The results show that as engine speed increases from 1400 r/min to 2600 r/min, the total heating capacity and energy consumption increase by about 30% and 89%, respectively; while the heat pump coefficient of performance(COP) and system primary energy ratio(PER) decrease by 44% and 31%, respectively. With the increase of ambient air temperature from 2.4 ℃ to 17.8 ℃, the heat pump COP and system PER increase by 32% and 19%, respectively. Moreover, the heat pump COP and system PER decrease by 27% and 15%, respectively, when the condenser water inlet temperature changes from 30 ℃ to 50 ℃. So, it is obvious that the effect of engine speed on the performance is more significant than the effects of ambient air temperature and condenser water inlet temperature.
文摘Energy is one of the most important resources in the economy of developing countries. Jordan depends mainly on imported oil and gas at international prices. This creates a heavy burden upon Jordanian national economy, which is reflected in the same time on other sectors of the Jordanian society. The ever increasing fuel prices make it very necessary to look for new renewable energy resources. Jordan as a developing country with its fast growing urban development and construction projects will be studied. It is worthy to study the dynamic relationship between end user, fuel and comfort in the residential sector. Energy is a chronic problem in Jordan, due to lack of non renewable energy resources, the end consumer is influenced by this fact, in achieving his basic energy needs. This study tries to shed light on the fuel poverty line, definitions and parameters of fuel poverty. And to study what has been done in this regard on both international and local level. No studies have been identified in Jordan which, explore the problem of fuel poverty, especially after the vast and recent increase in fuel prices internationally and locally. This study will follow theoretical and field survey to understand the relationship between comfort, energy and building fabric. Method will depend mainly on field survey and statistical data, and necessary measurements, questionnaires will be adopted when necessary to explore comfort levels related to fuel consumption. Summary and recommendations will be concerned with how thermal comfort could be achieved within the ranges of fuel accessibility, building fabric, minimum pollution and cost.
文摘The first available label standardizing a zero-balanced type of building is the Swiss Standard Minergie-A. The standard prescribes an annual net zero primary energy balance for heating, domestic hot water and ventilation. Electricity consumption for appliances and lighting is excluded. Additionally, Minergie-A is the first standard worldwide which includes a requirement in regard to embodied energy. Based on an analysis of 39 Minergie-A buildings, this paper shows that a wide range of different energy concepts and embodied energy strategies are possible in the scope of the label. The basis of all Minergie-A buildings is a well-insulated building envelope. However, the step from the Swiss Standard Minergie-A to a Net ZEB (net zero energy building) standard which includes electricity consumption for appliances and lighting is not a very big one. Increasing the size of the photovoltaic system is sufficient in most cases. Anyway, some of the Minergie-A buildings evaluated are also Net ZEBs. In this paper, it is also shown that the net zero balance during the operational phase of Net ZEBs clearly outweighs the increased embodied energy for additional materials in a life cycle energy analysis.
文摘There is a high potential for small-scale and medium scale wood-fired cogeneration in Estonia. The purpose of this research is to define the eligible capacity for wood fuel based cogeneration plant operating on the base of district heating systems in small towns. Results were checked and approbated by economical and environmental factors. Two optimal sizing methods were used maximizing of amount of heat year-round while working at full installed capacity and maximizing of amount of heat year-round while working with partial loads. Results of defining optimal capacities for wood-fired cogeneration plants in small Estonian towns showed that method of maximizing of amount of heat year-round while working with partial loads is more adequate to real situation.
基金This work is supported by National High Technology Research and Development Program of China(863 Program)(No.2011AA05A105)and SGCC Projects.
文摘What needs to be developed from the concept of"Smart Grid"is that:when renewable energy sources are absolutely prevailing in power generation,distributed power generation and distributed energy storage systems are widespread across the grid,and electric vehicle charging loads are prevailing in power load demands,how can the power grid support electric power as a core secondary energy source,undertake the role of a bridge between primary energy and end-use energy,and achieve the coordination and the optimization in macro energy perspective;how to guarantee the security of both macro energy and environment as well as the reliability of electricity.If a new term is needed,it should be Comprehensive Energy Network,not Energy Internet.
文摘Based on the integrated input output accounting system of natural resources and economy, Chinese 1992 Input Output Table and Chinese Statistics Year Book (1993) , one new and concrete Energy Economy Environmental Input Output Table, Chinese 92’Energy Economy Environmental Input Output Table is put forward in this paper, and scenario forecast and analysis of Chinese energy resources economy environmental situation (1992 2020) are given, too.
文摘To pursue the goal of sustainable mobility,two main paths can be considered:the electrification of vehicles and the use of biofuels,replacing fossil fuels,in internal combustion engine(ICE)vehicles.This paper proposes an analysis of different possible scenarios for automobiles towards a CO_(2)-neutral energy system,in the path of the use of biofuels and the production,distribution and use of biomethane.The study,an update of work presented previously,focuses on different scenarios that take into account numerous parameters that affect the overall efficiency of the production-and-use process.A Well-to-Wheel analysis is used to estimate the primary energy savings and reduction in greenhouse-gas emissions compared both to the use of fossil-based methane and to other fuels and automotive technologies.In particular,the study shows that the Non-Renewable Primary Energy Consumption(NRPEC)for biomethane is slightly higher(+9%)than that of biodiesel,but significantly lower than those of all the other power trains analysed:-69%compared to the battery electric vehicle(BEV)and-55%compared to bioethanol.Compared to the use of fossil natural gas,the NRPEC is reduced to just over a third(2.81).With regard to CO_(2) emissions,biomethane has the lowest values:-69%compared to BEV,-176%compared to bioethanol and-124%with respect to biodiesel.Compared to the use of fossil natural gas,the CO_(2) emissions are reduced over a third(3.55).Moreover,the paper shows that biomethane can completely cover the consumption of fossil methane for vehicles in Italy,proposing two different hypotheses:maximum production and minimum production.It is evident,therefore,that biomethane production can completely cover the consumption of fossil methane for vehicles:this means that the use of biomethane in the car can lead to a reduction in NRPEC equal to 28.9×10^(6) GJ/year and a reduction of CO_(2) emissions equal to 1.9×10^(6) t/year.
文摘The paper demonstrates how electromagnetic processing of materials(EPM)provides significant opportunities for saving primary energy and reducing carbon emissions in industrial thermal processes.Potentially electricity can replace up to 100%of other energy carriers currently used for process heat.For the time horizon from now to the year 2050 a transition scenario is developed and described.In this scenario the industrial processes are gradually switched from the actual situation to a situation with 100%electrically operated industrial processes.The developed scenarios take into account the most energy intensive industrial thermal processes,which could be replaced by electrothermal technologies and offer obviously the biggest future potential in terms of saving of primary energy and reducing of carbon emissions.As the average primary energy factor(PEF)gradually decreases from 2.5 currently,to 1 for a 100%renewable electricity system,the benefits of EPM will gradually increase.For each step in the development of the PEF the annual primary energy savings and annual reductions in greenhouse gas emissions are calculated and described in this paper.
文摘A floating type pendulum wave energy converter(FPWEC) with a rotary vane pump as the power take-off system was proposed by Watabe et al.in 1998.They showed that this device had high energy conversion efficiency.In the previous research,the authors conducted 2D wave tank tests in regular waves to evaluate the generating efficiency of FPWEC with a power take-off system composed of pulleys,belts and a generator.As a result,the influence of the electrical load on the generating efficiency was shown.Continuously,the load characteristics of FPWEC are pursued experimentally by using the servo motors to change the damping coefficient in this paper.In a later part of this paper,the motions of the model with the servo motors are compared with that of the case with the same power take-off system as the previous research.From the above experiment,it may be concluded that the maximum primary conversion efficiency is achieved as high as 98%at the optimal load.
基金financial support of the Ruohonjuuri Fund, Finland has made this case study possible
文摘Extreme weather events, sea level rise, and political disputes linked to climate change are driving masses to leave their homes. Their transitional settlements should be produced in a manner that causes minimum greenhouse gas(GHG) emissions to prevent any further acceleration of climate change and the humanitarian crises it causes. This article presents a study of the carbon footprint and primary energy demand of the construction materials of eight different transitional shelters. The lowest carbon footprints were found from shelter models made from bamboo or timber. The highest emissions were caused by shelters that have either a short service life or that are made from metal-intensive structures. The choice of cladding materials was surprisingly important. The findings were further compared to the overall impacts of each construction project, to national per capita GHG emissions,and to construction costs. Some shelter projects had notable total energy consumption even compared to the annual energy use of industrialized countries. The study concludes that construction materials have an important impact on the carbon footprint of shelters. Comparisons should however be made only between similar functional units. Furthermore, benchmark values and more background data are urgently needed in order to give humanitarian nongovernmental organizations tools for lowering the carbon footprint of their construction operations.
文摘With life cycle assessment(LCA) methodology,a life cycle model of coal-based vehicle fuels(CBVFs) including coal-based dimethyl ether(CBDME) and coal-based diesel(CBD) is established.Their primary energy consumption(PEC) and global warming potential(GWP) from well to wheel including feedstock extraction,fuel production,fuel consumption in vehicle and energy transportation are calculated and compared.Results show that the life cycle PEC and GWP of CBD pathway are 1.17 and 1.34 times as CBDME pathway.Based on the above results,CBDME will become a choice with great potential to replace conventional petroleum-based diesel (CPBD) in China.