Ecosystem services(ES)are the connection between nature and society,and are essential for the well-being of local communities that depend on them.In Ethiopia,church forests and the surrounding agricultural matrix supp...Ecosystem services(ES)are the connection between nature and society,and are essential for the well-being of local communities that depend on them.In Ethiopia,church forests and the surrounding agricultural matrix supply numerous ES.However,the ES delivered by both land use types have not yet been assessed simultaneously.Here we surveyed both church forests and their agricultural matrices,aiming to quantify,compare and unravel the drivers underlying tree-based ES supply,density and multifunctionality.We found that almost all church forests and half of the agricultural matrices provided high ES densities.ES multifunctionality was higher in the agricultural matrices,suggesting that people deliberately conserve or plant multifunctional tree species.Furthermore,the supply of all categories of ES was positively correlated with church forest age(p-value<0.001)in the agricultural matrix,while the extent of church forest was positively correlated with the density of all categories ecosystem services score in the church forests(p-value<0.001).Our results can be used to prioritize conservation efforts at sites that provide high levels of ES supply,ES density and ES multifunctionality,and to prioritize restoration efforts at sites with low levels thereof.展开更多
Using the 3-year observational data from ChinaFlux (Chinese Terrestrial Ecosystem Flux Research Network), we studied the gas regulation flux dynamics and cumulative process of gas regulation value in Qianyanzhou mid...Using the 3-year observational data from ChinaFlux (Chinese Terrestrial Ecosystem Flux Research Network), we studied the gas regulation flux dynamics and cumulative process of gas regulation value in Qianyanzhou middle subtropical plantation (QYF) and Changbai Mountain temperate mixed forest (CBF). The gas regulation service was differentiated into vegetation gas regulation service and net ecosystem gas regulation service. Carbon tax approach, reforestation cost approach and industrial oxygen approach were employed to calculate gas regulation value. Results show that there was significant seasonal variation in vegetation gas regulation flux. Daily CO2 uptake fluxes averaged 82.00 kg·ha^-·d^-1 and 59.37 kg·ha^-·d^-1 and the corresponding 02 emission fluxes were 59.65 kg·ha^-·d^-1 and 43.19 kg·ha^-·d^-1 for QYF and CBF, respectively. The cumulative curves of vegetation gas regulation value always followed a sigmoid shape, and the annual gas regulation value produced by vegetation was RMB 14342.69 yuan·ha^-1 and RMB 10384.18 yuan·ha^-1 for both QYF and CBF, respectively. In terms of monthly net ecosystem gas regulation service, QYF appeared as a CO2 sink and O2 source for the whole year, while CBF appeared to be a CO2 sink and O2 source mainly in the period between May and September. The cumulative curves of net ecosystem gas regulation value presented a sigmoid ("S") shape for QYF, while a unimodal type curve for CBF. The annual net ecosystem gas regulation value was 8470.52 yuan·ha^-1 and 5091.98yuan·ha^-1 for QYF and CBF, respectively. The economic value of both the vegetation gas regulation service and net ecosystem gas regulation service were mainly produced between May and October.展开更多
Hydrological service is a hot issue in the current researches of ecosystem service, particularly in the upper reaches of mountain rivers in dry land areas, where the Qilian Mountain is a representative one. The Qilian...Hydrological service is a hot issue in the current researches of ecosystem service, particularly in the upper reaches of mountain rivers in dry land areas, where the Qilian Mountain is a representative one. The Qilian Mountain, where forest, shrubland and grassland consist of its main ecosystems, can provide fresh water and many other ecosystem services, through a series of eco-hydrological process such as precipitation interception, soil water storage, and fresh water provision. Thus, monitoring water regulation and assessing the hydrological service of the Qilian Mountain are meaningful and helpful for the healthy development of the lower reaches of arid and semi-arid areas. In recent 10 years, hydrological services have been widely researched in terms of scale and landscape pattern, including water conservation, hydrological responses to afforestation and their ecological effects. This study, after analyzing lots of current models and applications of geographical information system(GIS) in hydrological services, gave a scientific and reasonable evaluation of mountain ecosystem in eco-hydrological services, by employing the combination of international forefronts and contentious issues into the Qilian Mountain. Assessments of hydrological services at regional or larger scales are limited compared with studies within watershed scale in the Qilian Mountain. In our evaluation results of forest ecosystems, it is concluded that long-term observation and dynamic monitoring of different types of ecosystem are indispensable, and the hydrological services and the potential variation in water supplement on regional and large scales should be central issues in the future research.v展开更多
The ecosystem-based management of nearshore waters requires integrated assessment of ocean health and scientific guidance on artificial regulations to promote sustainable development. Quantitative approaches were deve...The ecosystem-based management of nearshore waters requires integrated assessment of ocean health and scientific guidance on artificial regulations to promote sustainable development. Quantitative approaches were developed in this paper to assess present and near-term ocean health based on ecosystem services. Results of the case study in the Laizhou Bay of China showed that the index score of ocean health was 0.785 6 out of 1.0 at present and was expected to range from 0.555 1 to 0.804 1 in the near-term future depending on different intensities of artificial regulation of negative pressures. Specifically, the results of ocean health at present mainly indicated that cultural services and provisioning services performed essentially perfectly while supporting services and regulating services functioned less well. It can be concluded that this nearshore ecosystem would partially lose supporting and regulating services in the near-term future if the increasing pressures were not wellregulated but that all of these categories of ecosystem services could be slightly improved if the negative pressures were fully controlled. Additionally, it is recommended that publicity and education on ecosystem services especially on cultural services and regulating services should be further strengthened. The analytical process and resulting quantification provide flexible tools to guide future development of regulations so as to facilitate ecosystem-based management in the coastal zone.展开更多
Background:Forests contribute to human wellbeing through the provision of important ecosystem services.Methods:In this study,we investigated how the perceived importance of ecosystem services may impact the overall ...Background:Forests contribute to human wellbeing through the provision of important ecosystem services.Methods:In this study,we investigated how the perceived importance of ecosystem services may impact the overall benefit provided by managed watersheds at the Hubbard Brook Experimental Forest over a 45-year period,using standardized measures of service capacity weighted by service importance weights derived from a survey of beneficiaries.Results:The capacity of watersheds to regulate water flow and quality was high in all watersheds throughout the study period,whereas cultural services such as scenic beauty declined after harvest.Impacts on greenhouse gas regulation depended on the efficiency with which harvested biomass was used.Surveys revealed that stakeholders placed high value on all ecosystem services,with regulating and cultural services seen as more important than provisioning services.When service metrics were weighted by survey responses and aggregated into a single measure,total service provision followed the same overall trend as greenhouse gas regulation.Where biomass use was less efficient in terms of greenhouse gas emissions,harvesting resulted in an overall "ecosystem service debt";where use was more efficient,this "ecosystem service debt" was reduced.Beneficiaries' educational backgrounds significantly affected overall assessment of service provision.Beneficiaries with college or university degrees incurred smaller "ecosystem service debts" and were less negatively affected by harvesting overall.Conclusions:This study highlights the importance of including empirical measures of beneficiary preference when attempting to quantify overall provision of ecosystem services to human beneficiaries over time.展开更多
Valuation of ecosystem services has been sought as effective tools that enable the decision makers in designing the cost effective response policies for management of ecosystems towards alleviating the poverty especia...Valuation of ecosystem services has been sought as effective tools that enable the decision makers in designing the cost effective response policies for management of ecosystems towards alleviating the poverty especially in economically poor regions like South Asia. Various directions and linkages between poverty and degradation of ecosystem and reduced flow of ecosystem services can better be understood if the regulating services like hydrological flow and carbon sequestration by forest, and nutrient cycling and bioremediation: by wetlandv can be captured in monetary unit. South Asian Countries including India. Nepal, Pakistan and Bangladesh are the hotspots of poverty where poor depend upon various ecosystem services for their livelihoods and allocation of resource for conservation of ecosystems would have additional merit if regulating services are captured and internalized into the pubtic policy.The paperfirst raises problematic issues in valuation of regulatig ecosystem services, and attempts to link it withthe dependence of poor. Second, complexities of poverty-ecosystem dynamics are discussed. Thirdly, the possible in-tervention to achieve poverty alleviation goal is analyzed with the help of some examples from accounting and valua-tion of regulating services of lndian forest. Finally, the paper suggests that greater attention is needed to do credibleand better valuation of regulating Services so that insight from these ean be used in understanding the impact of degradation of ecosysterns On poor people.展开更多
To advance the field of science and technology,we need to revitalize the development of science and technology through innovation.The development of science and technology has many beneficial implications on the revit...To advance the field of science and technology,we need to revitalize the development of science and technology through innovation.The development of science and technology has many beneficial implications on the revitalization of the country.For this reason,universities in China should give full attention to their role as the main propeller of science and technology.“Streamlining administration,delegating powers,improving regulation,and strengthening services”is a policy issued by the Chinese government for the management of science and technology funds in colleges and universities.Based on the policy of“streamlining administration,delegating powers,improving regulation,and strengthening services,”colleges and universities must optimize the management of science and technology funds for their efficient use.In this paper,we analyzed the importance of the policy and put forward an effective management strategy,aiming to improve the management of science and technology funds in colleges and universities.展开更多
Ecosystem services were defined as the conditions and processes through which natural ecosystems, and the species that make them up, sustain and fulfill human life. They include provisioning, regulating, cultural, and...Ecosystem services were defined as the conditions and processes through which natural ecosystems, and the species that make them up, sustain and fulfill human life. They include provisioning, regulating, cultural, and supporting services. These form the basis on which regional environmental reserves and development are assessed and for the valuation of ecosystem services. In this paper Hainan Island is used as an example to explore methods of regulating services based on the structure and processes of a natural ecosystem. Ecosystems were classified into 13 types: valley rain forest, mountainous rain forest, tropical monsoon forest, mountainous coppice forest, mountainous evergreen forest, tropical coniferous forest, shrubs, plantation, timber forest, windbreak forest, mangrove, savanna, and crop land. Regulating services and their economic values for Hainan Island ecosystems were assessed and evaluated in terms of water-holding, soil conservancy, nutrient cycle, C fixation and windbreak functions. The economic value of the regulating services in 2002 were estimated at 2035.88×10^8 to 2153.39×10^8 Chinese Yuan (CNY), which was eight times the value of provisioning services (wood and agricultural products), estimated at just 254.06×10^8 CNY. Our analyses imply that ecosystem regulating services play a very important role in the sustainable development of Hainan Island's society and economy.展开更多
Photovoltaic(PV)and battery energy storage systems(BESSs)are key components in the energy market and crucial contributors to carbon emission reduction targets.These systems can not only provide energy but can also gen...Photovoltaic(PV)and battery energy storage systems(BESSs)are key components in the energy market and crucial contributors to carbon emission reduction targets.These systems can not only provide energy but can also generate considerable revenue by providing frequency regulation services and participating in carbon trading.This study proposes a bidding strategy for PV and BESSs operating in joint energy and frequency regulation markets,with a specific focus on carbon reduction benefits.A two-stage bidding framework that optimizes the profit of PV and BESSs is presented.In the first stage,the day-ahead energy market takes into account potential real-time forecast deviations.In the second stage,the real-time balancing market uses a rolling optimization method to account for multiple uncertainties.Notably,a real-time frequency regulation control method is proposed for the participation of PV and BESSs in automatic generation control(AGC).This is particularly relevant given the uncertainty of grid frequency fluctuations in the optimization model of the real-time balancing market.This control method dynamically assigns the frequency regulation amount undertaken by the PV and BESSs according to the control interval in which the area control error(ACE)occurs.The case study results demonstrate that the proposed bidding strategy not only enables the PV and BESSs to effectively participate in the grid frequency regulation response but also yields considerable carbon emission reduction benefits and effectively improves the system operation economy.展开更多
Introduction:Biodiversity and biodiversity-based ecosystems services are intrinsically dependent on the climate.During the twentieth century,climate change has posed major threats to biodiversity in Africa,and impacts...Introduction:Biodiversity and biodiversity-based ecosystems services are intrinsically dependent on the climate.During the twentieth century,climate change has posed major threats to biodiversity in Africa,and impacts are expected to increase as climate change continues and perhaps even accelerates.Outcomes:Our review shows that the multiple components of climate change are projected to affect all levels of biodiversity,from genes over species to biome level.Loss of biodiversity as a result of climate change can alter the structures and functions of African ecological systems.As a result,the provision of biodiversity-based ecosystem services and the wellbeing of people that rely on these services are being modified.Of particular concerns are“tipping points”where the exceedance of ecosystem thresholds will possibly lead to irreversible shifts of the structure of ecosystems and their services.In recent years,climate prediction models have portended continued warming and more frequent extreme weather events across the region.Such weather-related disturbances such as El Niño will place a premium on biodiversity and biodiversity-based ecosystem services that people rely on.Conclusion:As biodiversity underlies all goods and services provided by ecosystems that are crucial for human survival and well-being,this paper synthesizes and discusses observed and anticipated impacts of climate change on biodiversity and biodiversity-based ecosystem service provision and livelihoods,and what strategies might be employed to decrease current and future risks on the well-being of human in Africa.展开更多
In this paper, a new evaluation method of probabilistic TTC based on SVSR calculation is developed through a hierarchical simulation. A smooth technology based on the non-parametric kernel estimator is adapted to obta...In this paper, a new evaluation method of probabilistic TTC based on SVSR calculation is developed through a hierarchical simulation. A smooth technology based on the non-parametric kernel estimator is adapted to obtain the time-dependent probabilistic density function of the feeder-head load data. In order to describe possible operating change directions of the operating point, the original hyper-cone-like(HCL) model is constructed to consider the probabilistic distribution function(PDF) extracted from feeder-head load data to replace the simple Normal Distribution model and the uncertain generator outputs. To realize the fast TTC calculation of the current operating point in random conditions, a sub-hyper-cone-like(SHCL) model in full power injections space is proposed, which is a similarity transformation of the original one.展开更多
In northern China,thermal power units(TPUs)are important in improving the penetration level of renewable energy.In such areas,the potentials of coordinated dispatch of renewable energy sources(RESs)and TPUs can be bet...In northern China,thermal power units(TPUs)are important in improving the penetration level of renewable energy.In such areas,the potentials of coordinated dispatch of renewable energy sources(RESs)and TPUs can be better realized,if RESs and TPUs connected to the power grid at the same point of common coupling(PCC)are dispatched as a coupled system.Firstly,the definition of the coupled system is introduced,followed by an analysis on its characteristics.Secondly,based on the operation characteristics of deep peak regulation(DPR)of TPUs in the coupled system,the constraint of the ladder-type ramping rate applicable for day-ahead dispatch is proposed,and the corresponding flexible spinning reserve constraint is further established.Then,considering these constraints and peak regulation ancillary services,a day-ahead optimal dispatch model of the coupled system is established.Finally,the operational characteristics and advantages of the coupled system are analyzed in several case studies based on a real-world power grid in Liaoning province,China.The numerical results show that the coupled system can further improve the economic benefits of RESs and TPUs under the existing policies.展开更多
基金flnancial support from VLIR-UOS,Belgium through the VLIR-IUC Interuniversity cooperation with Bahir Dar University,Ethiopia (BDU-IUC)
文摘Ecosystem services(ES)are the connection between nature and society,and are essential for the well-being of local communities that depend on them.In Ethiopia,church forests and the surrounding agricultural matrix supply numerous ES.However,the ES delivered by both land use types have not yet been assessed simultaneously.Here we surveyed both church forests and their agricultural matrices,aiming to quantify,compare and unravel the drivers underlying tree-based ES supply,density and multifunctionality.We found that almost all church forests and half of the agricultural matrices provided high ES densities.ES multifunctionality was higher in the agricultural matrices,suggesting that people deliberately conserve or plant multifunctional tree species.Furthermore,the supply of all categories of ES was positively correlated with church forest age(p-value<0.001)in the agricultural matrix,while the extent of church forest was positively correlated with the density of all categories ecosystem services score in the church forests(p-value<0.001).Our results can be used to prioritize conservation efforts at sites that provide high levels of ES supply,ES density and ES multifunctionality,and to prioritize restoration efforts at sites with low levels thereof.
基金Chinese Terrestrial Ecosystem Flux Observational Research Network(ChinaFlux) for providing the observational data
文摘Using the 3-year observational data from ChinaFlux (Chinese Terrestrial Ecosystem Flux Research Network), we studied the gas regulation flux dynamics and cumulative process of gas regulation value in Qianyanzhou middle subtropical plantation (QYF) and Changbai Mountain temperate mixed forest (CBF). The gas regulation service was differentiated into vegetation gas regulation service and net ecosystem gas regulation service. Carbon tax approach, reforestation cost approach and industrial oxygen approach were employed to calculate gas regulation value. Results show that there was significant seasonal variation in vegetation gas regulation flux. Daily CO2 uptake fluxes averaged 82.00 kg·ha^-·d^-1 and 59.37 kg·ha^-·d^-1 and the corresponding 02 emission fluxes were 59.65 kg·ha^-·d^-1 and 43.19 kg·ha^-·d^-1 for QYF and CBF, respectively. The cumulative curves of vegetation gas regulation value always followed a sigmoid shape, and the annual gas regulation value produced by vegetation was RMB 14342.69 yuan·ha^-1 and RMB 10384.18 yuan·ha^-1 for both QYF and CBF, respectively. In terms of monthly net ecosystem gas regulation service, QYF appeared as a CO2 sink and O2 source for the whole year, while CBF appeared to be a CO2 sink and O2 source mainly in the period between May and September. The cumulative curves of net ecosystem gas regulation value presented a sigmoid ("S") shape for QYF, while a unimodal type curve for CBF. The annual net ecosystem gas regulation value was 8470.52 yuan·ha^-1 and 5091.98yuan·ha^-1 for QYF and CBF, respectively. The economic value of both the vegetation gas regulation service and net ecosystem gas regulation service were mainly produced between May and October.
基金Under the auspices of Ministry of Science and Technology of China(No.2012BAC08B01)
文摘Hydrological service is a hot issue in the current researches of ecosystem service, particularly in the upper reaches of mountain rivers in dry land areas, where the Qilian Mountain is a representative one. The Qilian Mountain, where forest, shrubland and grassland consist of its main ecosystems, can provide fresh water and many other ecosystem services, through a series of eco-hydrological process such as precipitation interception, soil water storage, and fresh water provision. Thus, monitoring water regulation and assessing the hydrological service of the Qilian Mountain are meaningful and helpful for the healthy development of the lower reaches of arid and semi-arid areas. In recent 10 years, hydrological services have been widely researched in terms of scale and landscape pattern, including water conservation, hydrological responses to afforestation and their ecological effects. This study, after analyzing lots of current models and applications of geographical information system(GIS) in hydrological services, gave a scientific and reasonable evaluation of mountain ecosystem in eco-hydrological services, by employing the combination of international forefronts and contentious issues into the Qilian Mountain. Assessments of hydrological services at regional or larger scales are limited compared with studies within watershed scale in the Qilian Mountain. In our evaluation results of forest ecosystems, it is concluded that long-term observation and dynamic monitoring of different types of ecosystem are indispensable, and the hydrological services and the potential variation in water supplement on regional and large scales should be central issues in the future research.v
基金The Public Science and Technology Research Funds Projects of Ocean in China under contract Nos 201005008 and201005009the National Natural Science Foundation of China under contract No.41206112
文摘The ecosystem-based management of nearshore waters requires integrated assessment of ocean health and scientific guidance on artificial regulations to promote sustainable development. Quantitative approaches were developed in this paper to assess present and near-term ocean health based on ecosystem services. Results of the case study in the Laizhou Bay of China showed that the index score of ocean health was 0.785 6 out of 1.0 at present and was expected to range from 0.555 1 to 0.804 1 in the near-term future depending on different intensities of artificial regulation of negative pressures. Specifically, the results of ocean health at present mainly indicated that cultural services and provisioning services performed essentially perfectly while supporting services and regulating services functioned less well. It can be concluded that this nearshore ecosystem would partially lose supporting and regulating services in the near-term future if the increasing pressures were not wellregulated but that all of these categories of ecosystem services could be slightly improved if the negative pressures were fully controlled. Additionally, it is recommended that publicity and education on ecosystem services especially on cultural services and regulating services should be further strengthened. The analytical process and resulting quantification provide flexible tools to guide future development of regulations so as to facilitate ecosystem-based management in the coastal zone.
基金support from the USDA Forest Service's Northeastern States Research Cooperative(NSRC)in collaboration with the Hubbard Brook Research Foundationthe Cary Institute of Ecosystem Studies
文摘Background:Forests contribute to human wellbeing through the provision of important ecosystem services.Methods:In this study,we investigated how the perceived importance of ecosystem services may impact the overall benefit provided by managed watersheds at the Hubbard Brook Experimental Forest over a 45-year period,using standardized measures of service capacity weighted by service importance weights derived from a survey of beneficiaries.Results:The capacity of watersheds to regulate water flow and quality was high in all watersheds throughout the study period,whereas cultural services such as scenic beauty declined after harvest.Impacts on greenhouse gas regulation depended on the efficiency with which harvested biomass was used.Surveys revealed that stakeholders placed high value on all ecosystem services,with regulating and cultural services seen as more important than provisioning services.When service metrics were weighted by survey responses and aggregated into a single measure,total service provision followed the same overall trend as greenhouse gas regulation.Where biomass use was less efficient in terms of greenhouse gas emissions,harvesting resulted in an overall "ecosystem service debt";where use was more efficient,this "ecosystem service debt" was reduced.Beneficiaries' educational backgrounds significantly affected overall assessment of service provision.Beneficiaries with college or university degrees incurred smaller "ecosystem service debts" and were less negatively affected by harvesting overall.Conclusions:This study highlights the importance of including empirical measures of beneficiary preference when attempting to quantify overall provision of ecosystem services to human beneficiaries over time.
文摘Valuation of ecosystem services has been sought as effective tools that enable the decision makers in designing the cost effective response policies for management of ecosystems towards alleviating the poverty especially in economically poor regions like South Asia. Various directions and linkages between poverty and degradation of ecosystem and reduced flow of ecosystem services can better be understood if the regulating services like hydrological flow and carbon sequestration by forest, and nutrient cycling and bioremediation: by wetlandv can be captured in monetary unit. South Asian Countries including India. Nepal, Pakistan and Bangladesh are the hotspots of poverty where poor depend upon various ecosystem services for their livelihoods and allocation of resource for conservation of ecosystems would have additional merit if regulating services are captured and internalized into the pubtic policy.The paperfirst raises problematic issues in valuation of regulatig ecosystem services, and attempts to link it withthe dependence of poor. Second, complexities of poverty-ecosystem dynamics are discussed. Thirdly, the possible in-tervention to achieve poverty alleviation goal is analyzed with the help of some examples from accounting and valua-tion of regulating services of lndian forest. Finally, the paper suggests that greater attention is needed to do credibleand better valuation of regulating Services so that insight from these ean be used in understanding the impact of degradation of ecosysterns On poor people.
文摘To advance the field of science and technology,we need to revitalize the development of science and technology through innovation.The development of science and technology has many beneficial implications on the revitalization of the country.For this reason,universities in China should give full attention to their role as the main propeller of science and technology.“Streamlining administration,delegating powers,improving regulation,and strengthening services”is a policy issued by the Chinese government for the management of science and technology funds in colleges and universities.Based on the policy of“streamlining administration,delegating powers,improving regulation,and strengthening services,”colleges and universities must optimize the management of science and technology funds for their efficient use.In this paper,we analyzed the importance of the policy and put forward an effective management strategy,aiming to improve the management of science and technology funds in colleges and universities.
基金National Natural Science Foundation of China No.40635029
文摘Ecosystem services were defined as the conditions and processes through which natural ecosystems, and the species that make them up, sustain and fulfill human life. They include provisioning, regulating, cultural, and supporting services. These form the basis on which regional environmental reserves and development are assessed and for the valuation of ecosystem services. In this paper Hainan Island is used as an example to explore methods of regulating services based on the structure and processes of a natural ecosystem. Ecosystems were classified into 13 types: valley rain forest, mountainous rain forest, tropical monsoon forest, mountainous coppice forest, mountainous evergreen forest, tropical coniferous forest, shrubs, plantation, timber forest, windbreak forest, mangrove, savanna, and crop land. Regulating services and their economic values for Hainan Island ecosystems were assessed and evaluated in terms of water-holding, soil conservancy, nutrient cycle, C fixation and windbreak functions. The economic value of the regulating services in 2002 were estimated at 2035.88×10^8 to 2153.39×10^8 Chinese Yuan (CNY), which was eight times the value of provisioning services (wood and agricultural products), estimated at just 254.06×10^8 CNY. Our analyses imply that ecosystem regulating services play a very important role in the sustainable development of Hainan Island's society and economy.
基金supported by the Jilin Province Science and Technology Development Plan Project(No.20220203163SF).
文摘Photovoltaic(PV)and battery energy storage systems(BESSs)are key components in the energy market and crucial contributors to carbon emission reduction targets.These systems can not only provide energy but can also generate considerable revenue by providing frequency regulation services and participating in carbon trading.This study proposes a bidding strategy for PV and BESSs operating in joint energy and frequency regulation markets,with a specific focus on carbon reduction benefits.A two-stage bidding framework that optimizes the profit of PV and BESSs is presented.In the first stage,the day-ahead energy market takes into account potential real-time forecast deviations.In the second stage,the real-time balancing market uses a rolling optimization method to account for multiple uncertainties.Notably,a real-time frequency regulation control method is proposed for the participation of PV and BESSs in automatic generation control(AGC).This is particularly relevant given the uncertainty of grid frequency fluctuations in the optimization model of the real-time balancing market.This control method dynamically assigns the frequency regulation amount undertaken by the PV and BESSs according to the control interval in which the area control error(ACE)occurs.The case study results demonstrate that the proposed bidding strategy not only enables the PV and BESSs to effectively participate in the grid frequency regulation response but also yields considerable carbon emission reduction benefits and effectively improves the system operation economy.
文摘Introduction:Biodiversity and biodiversity-based ecosystems services are intrinsically dependent on the climate.During the twentieth century,climate change has posed major threats to biodiversity in Africa,and impacts are expected to increase as climate change continues and perhaps even accelerates.Outcomes:Our review shows that the multiple components of climate change are projected to affect all levels of biodiversity,from genes over species to biome level.Loss of biodiversity as a result of climate change can alter the structures and functions of African ecological systems.As a result,the provision of biodiversity-based ecosystem services and the wellbeing of people that rely on these services are being modified.Of particular concerns are“tipping points”where the exceedance of ecosystem thresholds will possibly lead to irreversible shifts of the structure of ecosystems and their services.In recent years,climate prediction models have portended continued warming and more frequent extreme weather events across the region.Such weather-related disturbances such as El Niño will place a premium on biodiversity and biodiversity-based ecosystem services that people rely on.Conclusion:As biodiversity underlies all goods and services provided by ecosystems that are crucial for human survival and well-being,this paper synthesizes and discusses observed and anticipated impacts of climate change on biodiversity and biodiversity-based ecosystem service provision and livelihoods,and what strategies might be employed to decrease current and future risks on the well-being of human in Africa.
基金supported the National Hi-Tech Research and Development Program of China(Grant No.2015AA050403)the National Natural Science Foundation of China(Grant Nos.51277128+7 种基金51407125&51361135704)Statement of Collaboration between University of VictoriaCanadaTianjin UniversityChinaand"131"Talent&Innovative Team of Tianjin CityFundamental and Perspective Project of State Grid Corporation of China-"Study on the Energy Internet Technology Framework"Science and Technology Project of State Grid Corporation of China(Grant No.5217L0150004)
文摘In this paper, a new evaluation method of probabilistic TTC based on SVSR calculation is developed through a hierarchical simulation. A smooth technology based on the non-parametric kernel estimator is adapted to obtain the time-dependent probabilistic density function of the feeder-head load data. In order to describe possible operating change directions of the operating point, the original hyper-cone-like(HCL) model is constructed to consider the probabilistic distribution function(PDF) extracted from feeder-head load data to replace the simple Normal Distribution model and the uncertain generator outputs. To realize the fast TTC calculation of the current operating point in random conditions, a sub-hyper-cone-like(SHCL) model in full power injections space is proposed, which is a similarity transformation of the original one.
基金supported in part by the National Key Research and Development Program of China(No.2019YFB1505400).
文摘In northern China,thermal power units(TPUs)are important in improving the penetration level of renewable energy.In such areas,the potentials of coordinated dispatch of renewable energy sources(RESs)and TPUs can be better realized,if RESs and TPUs connected to the power grid at the same point of common coupling(PCC)are dispatched as a coupled system.Firstly,the definition of the coupled system is introduced,followed by an analysis on its characteristics.Secondly,based on the operation characteristics of deep peak regulation(DPR)of TPUs in the coupled system,the constraint of the ladder-type ramping rate applicable for day-ahead dispatch is proposed,and the corresponding flexible spinning reserve constraint is further established.Then,considering these constraints and peak regulation ancillary services,a day-ahead optimal dispatch model of the coupled system is established.Finally,the operational characteristics and advantages of the coupled system are analyzed in several case studies based on a real-world power grid in Liaoning province,China.The numerical results show that the coupled system can further improve the economic benefits of RESs and TPUs under the existing policies.