- Email: [email protected]
Comparison and Quantification Analysis Method of Urban Energy Consumption Features from Perspective of Urban Energy Interconnection
Available online at www.sciencedirect.com Available online at www.sciencedirect.com
ScienceDirect ScienceDirect
Energy Procedia 00 (2018) 000–000 Available online www.sciencedirect.com Available online atatwww.sciencedirect.com Energy Procedia 00 (2018) 000–000
ScienceDirect ScienceDirect
www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia
Energy (2018) 000–000 265–270 EnergyProcedia Procedia145 00 (2017) www.elsevier.com/locate/procedia
Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, Applied Energy Symposium and Forum, Energy Integration REM 2017, 18–20 Renewable October 2017, Tianjin, China with Mini/Microgrids, REM 2017, 18–20 October 2017, Tianjin, China
Comparison and Quantification Analysis Method of Urban Energy Comparison Analysis Method of Urban Theand 15th Quantification International Symposium on District Heating and Cooling Energy Consumption Features from Perspective of Urban Energy Consumption Features from Perspective of Urban Energy Interconnection Assessing the feasibility of using the heat demand-outdoor Interconnection temperature function for a long-term district heat demand forecast Xue Wanga, Qiang Suna, Guanyuan Weia, Fengzhang Luob, Wentao Yangb,*, Ke Xuc, a c c Xue Wanga, Qiang Suna, Guanyuan Wei , Fengzhang Luob, Wentaoc Yangb,*, Ke Xu , Zhe a,b,c a a Wang b c I. Andrić *, A. Pina , P. Ferrão , J.Wang Fournier ., B. Lacarrière , O. Le Corre c Zhe a
a China State Grid Energy Research Institute, Beijing 102209, China IN+ Center for Innovation, Technology andGrid Policy Researchof- Instituto Superior Técnico, Av. Rovisco300072, Pais 1, 1049-001 Lisbon, Portugal b a of Smart Key Laboratory of Energy Ministry Education, Tianjin University, China China State Grid Research Institute, Beijing 102209,Tianjin China b Veolia c Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France b State Grid Tianjin Electric Power Corporation, Tianjin 300010, China Key Laboratory of Smart Grid of Ministry of Education, Tianjin University, Tianjin 300072, China c Département Systèmes c Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France State Grid Tianjin Electric Power Corporation, Tianjin 300010, China
Abstract Abstract Abstract Growing severity of the environment pollution and urban energy exhaustion cause the proposal of the concept called “Urban Energy District heating of networks are commonly addressed inenergy the literature as one theproposal most effective solutions for“Urban decreasing the Growing the to environment andurban urban exhaustion causeofbased the of the concept called Energy Internet”,severity which adapts the idea of pollution sustainable development. The paper, on the consumption sector of urban energy, greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat Internet”, the which adapts to comparison the idea of sustainable development. The paper, based on the consumption sector of urbanofenergy, proposed quantitative and analysisurban system facing the urban energy consumption feature from perspective Urban sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, proposed the quantitative comparison andthe analysis system and facing the urban energy consumption feature fromconsumption perspective offeatures Urban Energy Internet. The system can make comparison quantification analysis of the urban energy prolonging the investment return Energy Internet. The can period. make of theeconomy, comparison and quantification of the energy consumption features comprehensively fromsystem the perspective security, environmentalanalysis protection andurban convenience. The comprehensive The main scope of thisthe paper is to assess feasibility of usingenvironmental the heat demand – outdoor function for heat demand comprehensively from perspective ofthe economy, security, protection andtemperature convenience. The comprehensive comparison and quantification analysis results can reflect the feature and advantages of each type of urban energy consumption forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 comparison and quantification analysis results reflect the The feature and advantages of each typethe of urban energy consumption and help seeking the optimal way of using the can urban energy. method proposed can improve efficiency of urban energy buildings that vary both construction period and energy. typology. Three weather scenarios (low, medium, high) andurban three district and help seeking the in optimal way of using the urban proposed can consciousness improve the efficiency consumption, reduce the environment pollutions, and promoteThe the method energy consumption of China of to speed energy up the renovation scenariosthe were developedpollutions, (shallow, intermediate, deep). To estimate the error, obtained of heat demand values consumption, environment and promote the energy consumption consciousness China to speed up were the transformationreduce of energy consumption pattern in China. compared with results from a dynamic heat demand model, previously developed and validated by the authors. transformation of energy consumption pattern in China. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications Copyright © 2018 Elsevier Ltd. All rights reserved. (the error© annual was lower 20% forLtd. all weather scenarios considered). However, after introducing renovation Copyright ©in2018 2018 Thedemand Authors. Published by Elsevier Copyright Elsevier Ltd. All rights than reserved. Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Selection responsibility of the scientific committee of theand Applied Energyscenarios Symposium and Forum, scenarios,and thepeer-review error valueunder increased up to 59.5% (depending on the weather renovation combination considered). Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017. Renewable Integration with Mini/Microgrids, 2017 The value Energy of slope coefficient increased on averageREM within the range of 3.8% up to 8% per decade, that corresponds to the Renewable Energy Integration with Mini/Microgrids, REM 2017. decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and Keywords: urban energy internet; electric energy substitution; energy consumption; energy comparison system renovation scenarios considered). the substitution; other hand,energy function intercept increased for 7.8-12.7% Keywords: urban energy internet; electricOn energy consumption; energy comparison system per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations. © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. * Corresponding author. Tel.: +86-182-22619637; fax: +86-22-27403544. Keywords: Heat demand; Forecast; Climate change E-mail address:author. [email protected] * Corresponding Tel.: +86-182-22619637; fax: +86-22-27403544. E-mail address: [email protected] 1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility the scientific 1876-6102 Copyright © 2018 Elsevier Ltd. All of rights reserved. committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017. Selection and peer-review under responsibility of the scientific 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, Peer-review under responsibility REM of the 2017. Scientific Committee of The 15th International Symposium on District Heating and Cooling. 1876-6102 Copyright © 2018 The Authors. Published by Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017 10.1016/j.egypro.2018.04.049
266 2
Xue Wang et al. / Energy Procedia 145 (2018) 265–270 Xue Wang et al. / Energy Procedia 00 (2018) 000–000
1. Introduction As the concentration centers of global population, cities are not only the highest intensity areas of energy consumption, but also the highest intensity areas of environment pollution. Cities occupy less than 1% of the earth's surface, but consume 76% of the coal, 63% of the oil and 82% of the gas of the world. In 2014, the amount of global energy consumption is equivalent to 12 billion 928 million tons of oil. Energy consumption of the world's 300 major cities accounted for more than 50% of all the cities, and the energy consumption per capital was 31.7 times as much as other areas [1]. Since 2013, smog has appeared in some provinces of China, which affect people’s health seriously. According to statistics, 80% of the PM2.5 pollution in China is related to energy consumption and more than 70% of the greenhouse gas emissions is related to fossil fuel consumption [2]. With the growing severity of the environment pollution problem caused by the increasing scarcity of urban energy, it is important to build Urban Energy Internet, which can integrate into the global energy Internet, achieve a wider range of energy resource allocation, promote the conversion of all types of energy with electric power and improve the proportion of clean energy use in both power generation side and power consumption side [3], [4]. Electric energy is a kind of clean and efficient secondary energy with zero CO2 emissions [5], [6]. There have been a lot of lectures expounding the necessity and key points of electric energy substitution, e.g. the economic and environmental benefits [7]-[9]. Lecture [10] compares the energy consumption intensity of coal, electricity and oil per unit of GDP, and make important conclusion that the adjustment of energy consumption structure is significant by using Laspeyres decomposition method. Lecture [11] analyzes the effect of the increase of electric power price on industry products price using the input-output model. Junqueira Reis et al propose that demand side participation in power substitution can improve the efficiency of electric energy substitution [12], [13]. The research about the energy substitution above pay more attention on environmental protection and economy efficiency on the macro level [14][16]. The research on urban energy substitution and the comparison and analysis of different kinds of urban energy in the local urban area should be studied further. Bases on the urban energy consumption sector, this paper proposed the quantitative comparison and analysis index system of urban energy consumption features for Urban Energy Internet. The system can make the comparison and quantification analysis of the urban energy consumption features comprehensively from the perspective of economy, security, environmental protection and convenience. The comprehensive comparison and quantification analysis results can reflect the characteristics and advantages of each type of urban energy and help seeking the optimal way of using different urban energy. (1) Construction of comparative analysis system
Analysis of urban energy environment and consumption characteristics Urban energy consumption comparative index system Economy
Security
Environmental friendliness
Accessibility
(2) Model of comparative analysis index
Quantitative Quantitative model of Quantitative Quantitative model of model of consumption model of consumption consumption safety environmental consumption economy protection portability
Comprehensive evaluation system
(3) Implementation of comprehensive comparative analysis Establishment of index evaluation Index evaluation criteria selection standard Index weight setting Single index evaluation
Comprehensive evaluation
Comprehensive comparison and analysis of urban energy
Preferred city energy
Fig. 1. Flow chart of the comparison and analysis method of consumption features quantification
Xue Wang et al. / Energy Procedia 145 (2018) 265–270 Xue Wang et al. / Energy Procedia 00 (2018) 000–000
267 3
2. Quantitative Comparison Framework Of Urban Energy Consumption As shown in Fig.1, the flow chart of the quantitative comparison and analysis method of urban energy consumption mainly includes 3 aspects: (1) building the comparison system of different kinds of urban energy; (2) building models which can reflect the consumption features of urban energy; and (3) Conducting the comprehensive comparison and analysis of urban energy consumption features. 3. Quantitative Model And Index Of Urban Energy Consumption Features At present, the common urban energy in the consumption sector includes electric energy, gas, coal, oil and so on [17], [18]. According to the features of urban energy consumption and the demand of users, the paper builds comparing and analyzing system of urban energy from economy, security, environmental protection and convenience of four aspects. 1) Economic model of energy consumption The economic efficiency of different kinds of urban energy can be obtained through the energy consumption required to supply the same amount of heat. It can be estimated by (1) and (2):
Ei =
Q Ci ⋅ηi
(1)
In (1), Ei is the ith energy consumption which provides a certain amount of heat. Q is the consumption of heat. Ci is the calorific value of the ith energy consumption. ηi is the conversion efficiency of the ith energy consumption.
Pi = Ei ⋅ pi
(2)
In (2), Pi is the economic cost of the ith energy consumption. pi is the unit-price of the ith energy. Security model of energy consumption 2) The way to quantify the security of urban energy consumption is calculating the economic loss which is caused by the safety accidents during the urban energy consumption. It can be estimated by (3):
Si = Ai ⋅ si
(3)
In (3), Si is the security cost of the ith energy. Ai is the total number of accidents during the ith energy consumption per year. si is the average economic loss of per accident of the ith urban energy consumption. Energy consumption environmental protection model 3) The environment cost of one kind of energy can be calculated through the pollutant discharge level which is caused during the urban energy consumption. It can be estimated by (4), (5) and (6):
Oi = Ei ⋅ oi
(4)
Gi = Ei ⋅ gi
(5)
N i = Ei ⋅ ni
(6)
In (4), (5) and (6), Oi and Gi, and Ni are the emission of CO2, SO2 and NOx during the ith energy consumption. oi, gi and ni are the CO2, SO2 and NOx emission factors of the ith energy respectively. Energy consumption convenience model 4)
Xue Wang et al. / Energy Procedia 145 (2018) 265–270 Xue Wang et al. / Energy Procedia 00 (2018) 000–000
268 4
The convenience of a certain kind of energy for consumer consumption is an important index. Similar to the "power supply radius" in the field of urban power network. The consumption radius is used to quantify the convenience of one kind of urban energy consumption. The index αi is used to present the consumption radius of ith urban energy. Then, Delphi method is used to determine the weight. Tab.1 shows the weighting system which are determined by experts committed to urban energy consumption from big city such as Beijing, Tianjin, Shandong, Hunan and Henan. Tab.1 also shows the corresponding evaluation functions of piece-wise linear functions. Table 1. Weight and evaluation function of the analysis hierarchy of urban consumption energy Weight
Evaluation function
Economy
Type
0.4
-7.23x+117.81
Security
0.2
-0.00122x+100.18
0.3
-0.932x+100/-1.96x+100/-5.38x+100
0.1
-0.0095x+100.05
Environmental protection
CO2(0.4)/SO2(0.3)/NOx(0.3)
Convenience
4. Case Study According to the actual situation of urban energy consumption, the paper mainly compares and analyzes the consumption features of four energies: electric energy, gas, standard coal and diesel oil. As to the aspect of economy and environmental protection, the case takes boiling 100kg water as the analysis target to investigate the energy consumption and pollutant emissions. As to the aspect of security, the data of accidents during 2014 national urban energy consumption side is used. As to the aspect of convenience, the case calculates the moving average distance of four kinds of energy consumption. Tab.2 shows the data needed for calculating. Table 2. Basic data of the case study Data item
Electric energy
Natural gas
Standard coal
Diesel oil
Calorific value(Kcal/kWh, Kcal/m3, Kcal/kg, Kcal/L)
857
9500
7000
8686
Heat transfer efficiency
0.8
0.57
0.20
0.335
Energy price(RMB/kWh, RMB/m3, RMB/t, RMB/L)
0.49
2.4
480
4.92
Total number of accidents in 2014
5
350
6
7
Average economic loss of accident (Million RMB)
30
200
70
200
CO2 emission factor(kg/m3, kg/kg, kg/kg)
0
3.71
2.77
5.52
SO2 emission factor(g/m3, g/kg, g/kg)
0
0.102
16
10.53
NOx emission factor(kg/m3, g/kg, g/kg)
0
0.63
7.6
9
Energy consumption radius (m)
5
15
1000
2000
Fig. 2. Economy comparison of urban energies
Fig. 3. Security comparison of urban energies
Based on the data item of Tab.2, the comparison and analysis result of four aspects of urban energy consumption is calculated through (1) to (6) shown in Fig.2 to Fig.5. The comprehensive comparison and analysis results of the urban energy consumption, is as shown in Tab.3.
Xue Wang et al. / Energy Procedia 145 (2018) 265–270 Xue Wang et al. / Energy Procedia 00 (2018) 000–000
269 5
Fig.6 shows the radar chart of four aspects of urban energy consumption. In view of the main consumption form of urban energy such as electric, gas, coal and oils, the comparison results of urban energy consumption from four aspects indicate that: in addition to the economy efficiency, electric energy has a strong advantage relative to other forms of urban energy whether from the unilateral indicators or overall comprehensive indicators. Due to gas, oils, coal and other forms of urban energy can be transferred into electric energy conveniently. It can be said that electricity is the optimal use of urban energy.
Fig. 4. Environmental friendliness comparison of urban energies
Fig. 5. Convenience comparison result of urban energies
Table 3. Comparative score of four aspects of urban consumption energies Consumption energy
Electric energy
Natural gas
Standard coal
Economy(0.4)
76.6
92.3
98.0
Security(0.2)
100.0
9.2
99.7
Environmental friendliness(0.3)
100.0
87.64
15.0
Convenience(0.1)
100.0
99.9
5.0
Overall Score
90.6
75.0
64.1
Fig. 6. Radar chart of four aspects of urban consumption energies
5. Conclusion A quantitative comparative analysis system and method for urban energy consumption pattern is put forward in this paper. The case results show that: The comprehensive comparison and analysis results can reflect the characteristics and advantages of each type of urban energy consumption in many ways and help seeking the optimal way of using the urban energy. The method can improve the efficiency of urban energy consumption, reduce the environment pollutions, promote the energy consumption consciousness of China and also speed up the transformation of energy consumption pattern in China. Electric energy, as the best energy source of urban energy, will be the important support of the sustainable development of urban energy.
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Xue Wang et al. / Energy Procedia 145 (2018) 265–270 Xue Wang et al. / Energy Procedia 00 (2018) 000–000
Acknowledgements This work is supported by National Natural Science Foundation of China (51207101); Science and Technology Projects of State Grid Corporation of China (SGXJJY00GHJS1700020). References [1] Wang W and Huang K. The Strategy of Electric Power Alteration: Opportunities, Challenges and Policy Options. Journal of North China Electric Power University: Social Sciences 2014; 4: 1-5. [2] Jiang L, Yuan Y, Wang Z, et al. Evaluation index system and comprehensive evaluation method of energy internet in innovative demonstration area of smart grid. Proceedings of the CSU-EPSA 2016; 28(1): 39-45. [3] Liu ZY, Global Energy Internet. vol. I. Beijing: China Electric Power Press; 2015. [4] Zhang Y. Electric energy substitution: walking on the road of cleaning, environmental protection and sustainable development. State Grid News 2013; 10: 34-40. [6] Zhang Y, Niu DX and Gu ZH. Electric energy substitution in terminal energy. Modern Economies 2008; 7: 61-62, 65. [7] Cao DL, Yuan Y, and Li ZX. Application and efficiency evaluation of alternative energy. Power System and Clean Energy 2011; 27: 3034. [8] Yin H. Energy conservation and emission reduction in the environment of electric energy alternative to other energy evaluation methods study. Master Dissertation. Beijing: North China Electric Power University; 2013. [9] Zhao YH. The analysis and optimization model of Beijing's energy substitution for the environment reduction targets. Ph.D. Dissertation, Beijing: North China Electric Power University; 2014. [10] Steenhof PA. Decomposition of electricity demand in China's industrial sector. Energy Economics 2006; 28: 370-384. [11] Nguyen KQ. Impacts of a rise in electricity tariff on prices of other products in Vietnam. Energy Policy 2008; 36: 3135-3139. [12] Reis MCJ and Coda HB. Physical and geometrical non-linear analysis of plane frames considering elastoplastic semi-rigid connections by the positional FEM. Latin American Journal of Solids & Structures 2014; 11: 1163-1189. [13] Yang YT, Fishbain B, Hochbaum DS, et al. The Supervised Normalized Cut Method for Detecting, Classifying, and Identifying Special Nuclear Materials. Informs Journal on Computing 2014; 26: 45-58. [14] Liang XL, Lu L and Zhou HM.Alternative energy in the energy network. Smart Grid 2015; 3: 1192-1196. [15] Yan QY, Zhu ML and Tang XF.Electrical Energy Alternative Research Based on the Cost Utility Analysis. Operations Research and Management Science 2015; 24: 176-183. [16] Dong X, Zhu YG, Wang F, et al. The future development model of Hubei area under the implementation of electric energy substitution strategy. Applied Energy Technology 2015; 11: 38-40. [17] Liang J and Zhang XL. Analysis on spatial distribution characteristics of urban energy consumption among capital cities in China. Resources science 2009; 31: 2086-2092. [18] Han LN. Research on energy structure in China. Ph.D. Dissertation. ShangHai: Shanghai Jiao Tong University. 2007.
ScienceDirect ScienceDirect
Energy Procedia 00 (2018) 000–000 Available online www.sciencedirect.com Available online atatwww.sciencedirect.com Energy Procedia 00 (2018) 000–000
ScienceDirect ScienceDirect
www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia
Energy (2018) 000–000 265–270 EnergyProcedia Procedia145 00 (2017) www.elsevier.com/locate/procedia
Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, Applied Energy Symposium and Forum, Energy Integration REM 2017, 18–20 Renewable October 2017, Tianjin, China with Mini/Microgrids, REM 2017, 18–20 October 2017, Tianjin, China
Comparison and Quantification Analysis Method of Urban Energy Comparison Analysis Method of Urban Theand 15th Quantification International Symposium on District Heating and Cooling Energy Consumption Features from Perspective of Urban Energy Consumption Features from Perspective of Urban Energy Interconnection Assessing the feasibility of using the heat demand-outdoor Interconnection temperature function for a long-term district heat demand forecast Xue Wanga, Qiang Suna, Guanyuan Weia, Fengzhang Luob, Wentao Yangb,*, Ke Xuc, a c c Xue Wanga, Qiang Suna, Guanyuan Wei , Fengzhang Luob, Wentaoc Yangb,*, Ke Xu , Zhe a,b,c a a Wang b c I. Andrić *, A. Pina , P. Ferrão , J.Wang Fournier ., B. Lacarrière , O. Le Corre c Zhe a
a China State Grid Energy Research Institute, Beijing 102209, China IN+ Center for Innovation, Technology andGrid Policy Researchof- Instituto Superior Técnico, Av. Rovisco300072, Pais 1, 1049-001 Lisbon, Portugal b a of Smart Key Laboratory of Energy Ministry Education, Tianjin University, China China State Grid Research Institute, Beijing 102209,Tianjin China b Veolia c Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France b State Grid Tianjin Electric Power Corporation, Tianjin 300010, China Key Laboratory of Smart Grid of Ministry of Education, Tianjin University, Tianjin 300072, China c Département Systèmes c Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France State Grid Tianjin Electric Power Corporation, Tianjin 300010, China
Abstract Abstract Abstract Growing severity of the environment pollution and urban energy exhaustion cause the proposal of the concept called “Urban Energy District heating of networks are commonly addressed inenergy the literature as one theproposal most effective solutions for“Urban decreasing the Growing the to environment andurban urban exhaustion causeofbased the of the concept called Energy Internet”,severity which adapts the idea of pollution sustainable development. The paper, on the consumption sector of urban energy, greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat Internet”, the which adapts to comparison the idea of sustainable development. The paper, based on the consumption sector of urbanofenergy, proposed quantitative and analysisurban system facing the urban energy consumption feature from perspective Urban sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, proposed the quantitative comparison andthe analysis system and facing the urban energy consumption feature fromconsumption perspective offeatures Urban Energy Internet. The system can make comparison quantification analysis of the urban energy prolonging the investment return Energy Internet. The can period. make of theeconomy, comparison and quantification of the energy consumption features comprehensively fromsystem the perspective security, environmentalanalysis protection andurban convenience. The comprehensive The main scope of thisthe paper is to assess feasibility of usingenvironmental the heat demand – outdoor function for heat demand comprehensively from perspective ofthe economy, security, protection andtemperature convenience. The comprehensive comparison and quantification analysis results can reflect the feature and advantages of each type of urban energy consumption forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 comparison and quantification analysis results reflect the The feature and advantages of each typethe of urban energy consumption and help seeking the optimal way of using the can urban energy. method proposed can improve efficiency of urban energy buildings that vary both construction period and energy. typology. Three weather scenarios (low, medium, high) andurban three district and help seeking the in optimal way of using the urban proposed can consciousness improve the efficiency consumption, reduce the environment pollutions, and promoteThe the method energy consumption of China of to speed energy up the renovation scenariosthe were developedpollutions, (shallow, intermediate, deep). To estimate the error, obtained of heat demand values consumption, environment and promote the energy consumption consciousness China to speed up were the transformationreduce of energy consumption pattern in China. compared with results from a dynamic heat demand model, previously developed and validated by the authors. transformation of energy consumption pattern in China. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications Copyright © 2018 Elsevier Ltd. All rights reserved. (the error© annual was lower 20% forLtd. all weather scenarios considered). However, after introducing renovation Copyright ©in2018 2018 Thedemand Authors. Published by Elsevier Copyright Elsevier Ltd. All rights than reserved. Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Selection responsibility of the scientific committee of theand Applied Energyscenarios Symposium and Forum, scenarios,and thepeer-review error valueunder increased up to 59.5% (depending on the weather renovation combination considered). Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017. Renewable Integration with Mini/Microgrids, 2017 The value Energy of slope coefficient increased on averageREM within the range of 3.8% up to 8% per decade, that corresponds to the Renewable Energy Integration with Mini/Microgrids, REM 2017. decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and Keywords: urban energy internet; electric energy substitution; energy consumption; energy comparison system renovation scenarios considered). the substitution; other hand,energy function intercept increased for 7.8-12.7% Keywords: urban energy internet; electricOn energy consumption; energy comparison system per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations. © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. * Corresponding author. Tel.: +86-182-22619637; fax: +86-22-27403544. Keywords: Heat demand; Forecast; Climate change E-mail address:author. [email protected] * Corresponding Tel.: +86-182-22619637; fax: +86-22-27403544. E-mail address: [email protected] 1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility the scientific 1876-6102 Copyright © 2018 Elsevier Ltd. All of rights reserved. committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017. Selection and peer-review under responsibility of the scientific 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, Peer-review under responsibility REM of the 2017. Scientific Committee of The 15th International Symposium on District Heating and Cooling. 1876-6102 Copyright © 2018 The Authors. Published by Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017 10.1016/j.egypro.2018.04.049
266 2
Xue Wang et al. / Energy Procedia 145 (2018) 265–270 Xue Wang et al. / Energy Procedia 00 (2018) 000–000
1. Introduction As the concentration centers of global population, cities are not only the highest intensity areas of energy consumption, but also the highest intensity areas of environment pollution. Cities occupy less than 1% of the earth's surface, but consume 76% of the coal, 63% of the oil and 82% of the gas of the world. In 2014, the amount of global energy consumption is equivalent to 12 billion 928 million tons of oil. Energy consumption of the world's 300 major cities accounted for more than 50% of all the cities, and the energy consumption per capital was 31.7 times as much as other areas [1]. Since 2013, smog has appeared in some provinces of China, which affect people’s health seriously. According to statistics, 80% of the PM2.5 pollution in China is related to energy consumption and more than 70% of the greenhouse gas emissions is related to fossil fuel consumption [2]. With the growing severity of the environment pollution problem caused by the increasing scarcity of urban energy, it is important to build Urban Energy Internet, which can integrate into the global energy Internet, achieve a wider range of energy resource allocation, promote the conversion of all types of energy with electric power and improve the proportion of clean energy use in both power generation side and power consumption side [3], [4]. Electric energy is a kind of clean and efficient secondary energy with zero CO2 emissions [5], [6]. There have been a lot of lectures expounding the necessity and key points of electric energy substitution, e.g. the economic and environmental benefits [7]-[9]. Lecture [10] compares the energy consumption intensity of coal, electricity and oil per unit of GDP, and make important conclusion that the adjustment of energy consumption structure is significant by using Laspeyres decomposition method. Lecture [11] analyzes the effect of the increase of electric power price on industry products price using the input-output model. Junqueira Reis et al propose that demand side participation in power substitution can improve the efficiency of electric energy substitution [12], [13]. The research about the energy substitution above pay more attention on environmental protection and economy efficiency on the macro level [14][16]. The research on urban energy substitution and the comparison and analysis of different kinds of urban energy in the local urban area should be studied further. Bases on the urban energy consumption sector, this paper proposed the quantitative comparison and analysis index system of urban energy consumption features for Urban Energy Internet. The system can make the comparison and quantification analysis of the urban energy consumption features comprehensively from the perspective of economy, security, environmental protection and convenience. The comprehensive comparison and quantification analysis results can reflect the characteristics and advantages of each type of urban energy and help seeking the optimal way of using different urban energy. (1) Construction of comparative analysis system
Analysis of urban energy environment and consumption characteristics Urban energy consumption comparative index system Economy
Security
Environmental friendliness
Accessibility
(2) Model of comparative analysis index
Quantitative Quantitative model of Quantitative Quantitative model of model of consumption model of consumption consumption safety environmental consumption economy protection portability
Comprehensive evaluation system
(3) Implementation of comprehensive comparative analysis Establishment of index evaluation Index evaluation criteria selection standard Index weight setting Single index evaluation
Comprehensive evaluation
Comprehensive comparison and analysis of urban energy
Preferred city energy
Fig. 1. Flow chart of the comparison and analysis method of consumption features quantification
Xue Wang et al. / Energy Procedia 145 (2018) 265–270 Xue Wang et al. / Energy Procedia 00 (2018) 000–000
267 3
2. Quantitative Comparison Framework Of Urban Energy Consumption As shown in Fig.1, the flow chart of the quantitative comparison and analysis method of urban energy consumption mainly includes 3 aspects: (1) building the comparison system of different kinds of urban energy; (2) building models which can reflect the consumption features of urban energy; and (3) Conducting the comprehensive comparison and analysis of urban energy consumption features. 3. Quantitative Model And Index Of Urban Energy Consumption Features At present, the common urban energy in the consumption sector includes electric energy, gas, coal, oil and so on [17], [18]. According to the features of urban energy consumption and the demand of users, the paper builds comparing and analyzing system of urban energy from economy, security, environmental protection and convenience of four aspects. 1) Economic model of energy consumption The economic efficiency of different kinds of urban energy can be obtained through the energy consumption required to supply the same amount of heat. It can be estimated by (1) and (2):
Ei =
Q Ci ⋅ηi
(1)
In (1), Ei is the ith energy consumption which provides a certain amount of heat. Q is the consumption of heat. Ci is the calorific value of the ith energy consumption. ηi is the conversion efficiency of the ith energy consumption.
Pi = Ei ⋅ pi
(2)
In (2), Pi is the economic cost of the ith energy consumption. pi is the unit-price of the ith energy. Security model of energy consumption 2) The way to quantify the security of urban energy consumption is calculating the economic loss which is caused by the safety accidents during the urban energy consumption. It can be estimated by (3):
Si = Ai ⋅ si
(3)
In (3), Si is the security cost of the ith energy. Ai is the total number of accidents during the ith energy consumption per year. si is the average economic loss of per accident of the ith urban energy consumption. Energy consumption environmental protection model 3) The environment cost of one kind of energy can be calculated through the pollutant discharge level which is caused during the urban energy consumption. It can be estimated by (4), (5) and (6):
Oi = Ei ⋅ oi
(4)
Gi = Ei ⋅ gi
(5)
N i = Ei ⋅ ni
(6)
In (4), (5) and (6), Oi and Gi, and Ni are the emission of CO2, SO2 and NOx during the ith energy consumption. oi, gi and ni are the CO2, SO2 and NOx emission factors of the ith energy respectively. Energy consumption convenience model 4)
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The convenience of a certain kind of energy for consumer consumption is an important index. Similar to the "power supply radius" in the field of urban power network. The consumption radius is used to quantify the convenience of one kind of urban energy consumption. The index αi is used to present the consumption radius of ith urban energy. Then, Delphi method is used to determine the weight. Tab.1 shows the weighting system which are determined by experts committed to urban energy consumption from big city such as Beijing, Tianjin, Shandong, Hunan and Henan. Tab.1 also shows the corresponding evaluation functions of piece-wise linear functions. Table 1. Weight and evaluation function of the analysis hierarchy of urban consumption energy Weight
Evaluation function
Economy
Type
0.4
-7.23x+117.81
Security
0.2
-0.00122x+100.18
0.3
-0.932x+100/-1.96x+100/-5.38x+100
0.1
-0.0095x+100.05
Environmental protection
CO2(0.4)/SO2(0.3)/NOx(0.3)
Convenience
4. Case Study According to the actual situation of urban energy consumption, the paper mainly compares and analyzes the consumption features of four energies: electric energy, gas, standard coal and diesel oil. As to the aspect of economy and environmental protection, the case takes boiling 100kg water as the analysis target to investigate the energy consumption and pollutant emissions. As to the aspect of security, the data of accidents during 2014 national urban energy consumption side is used. As to the aspect of convenience, the case calculates the moving average distance of four kinds of energy consumption. Tab.2 shows the data needed for calculating. Table 2. Basic data of the case study Data item
Electric energy
Natural gas
Standard coal
Diesel oil
Calorific value(Kcal/kWh, Kcal/m3, Kcal/kg, Kcal/L)
857
9500
7000
8686
Heat transfer efficiency
0.8
0.57
0.20
0.335
Energy price(RMB/kWh, RMB/m3, RMB/t, RMB/L)
0.49
2.4
480
4.92
Total number of accidents in 2014
5
350
6
7
Average economic loss of accident (Million RMB)
30
200
70
200
CO2 emission factor(kg/m3, kg/kg, kg/kg)
0
3.71
2.77
5.52
SO2 emission factor(g/m3, g/kg, g/kg)
0
0.102
16
10.53
NOx emission factor(kg/m3, g/kg, g/kg)
0
0.63
7.6
9
Energy consumption radius (m)
5
15
1000
2000
Fig. 2. Economy comparison of urban energies
Fig. 3. Security comparison of urban energies
Based on the data item of Tab.2, the comparison and analysis result of four aspects of urban energy consumption is calculated through (1) to (6) shown in Fig.2 to Fig.5. The comprehensive comparison and analysis results of the urban energy consumption, is as shown in Tab.3.
Xue Wang et al. / Energy Procedia 145 (2018) 265–270 Xue Wang et al. / Energy Procedia 00 (2018) 000–000
269 5
Fig.6 shows the radar chart of four aspects of urban energy consumption. In view of the main consumption form of urban energy such as electric, gas, coal and oils, the comparison results of urban energy consumption from four aspects indicate that: in addition to the economy efficiency, electric energy has a strong advantage relative to other forms of urban energy whether from the unilateral indicators or overall comprehensive indicators. Due to gas, oils, coal and other forms of urban energy can be transferred into electric energy conveniently. It can be said that electricity is the optimal use of urban energy.
Fig. 4. Environmental friendliness comparison of urban energies
Fig. 5. Convenience comparison result of urban energies
Table 3. Comparative score of four aspects of urban consumption energies Consumption energy
Electric energy
Natural gas
Standard coal
Economy(0.4)
76.6
92.3
98.0
Security(0.2)
100.0
9.2
99.7
Environmental friendliness(0.3)
100.0
87.64
15.0
Convenience(0.1)
100.0
99.9
5.0
Overall Score
90.6
75.0
64.1
Fig. 6. Radar chart of four aspects of urban consumption energies
5. Conclusion A quantitative comparative analysis system and method for urban energy consumption pattern is put forward in this paper. The case results show that: The comprehensive comparison and analysis results can reflect the characteristics and advantages of each type of urban energy consumption in many ways and help seeking the optimal way of using the urban energy. The method can improve the efficiency of urban energy consumption, reduce the environment pollutions, promote the energy consumption consciousness of China and also speed up the transformation of energy consumption pattern in China. Electric energy, as the best energy source of urban energy, will be the important support of the sustainable development of urban energy.
270 6
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Acknowledgements This work is supported by National Natural Science Foundation of China (51207101); Science and Technology Projects of State Grid Corporation of China (SGXJJY00GHJS1700020). References [1] Wang W and Huang K. The Strategy of Electric Power Alteration: Opportunities, Challenges and Policy Options. Journal of North China Electric Power University: Social Sciences 2014; 4: 1-5. [2] Jiang L, Yuan Y, Wang Z, et al. Evaluation index system and comprehensive evaluation method of energy internet in innovative demonstration area of smart grid. Proceedings of the CSU-EPSA 2016; 28(1): 39-45. [3] Liu ZY, Global Energy Internet. vol. I. Beijing: China Electric Power Press; 2015. [4] Zhang Y. Electric energy substitution: walking on the road of cleaning, environmental protection and sustainable development. State Grid News 2013; 10: 34-40. [6] Zhang Y, Niu DX and Gu ZH. Electric energy substitution in terminal energy. Modern Economies 2008; 7: 61-62, 65. [7] Cao DL, Yuan Y, and Li ZX. Application and efficiency evaluation of alternative energy. Power System and Clean Energy 2011; 27: 3034. [8] Yin H. Energy conservation and emission reduction in the environment of electric energy alternative to other energy evaluation methods study. Master Dissertation. Beijing: North China Electric Power University; 2013. [9] Zhao YH. The analysis and optimization model of Beijing's energy substitution for the environment reduction targets. Ph.D. Dissertation, Beijing: North China Electric Power University; 2014. [10] Steenhof PA. Decomposition of electricity demand in China's industrial sector. Energy Economics 2006; 28: 370-384. [11] Nguyen KQ. Impacts of a rise in electricity tariff on prices of other products in Vietnam. Energy Policy 2008; 36: 3135-3139. [12] Reis MCJ and Coda HB. Physical and geometrical non-linear analysis of plane frames considering elastoplastic semi-rigid connections by the positional FEM. Latin American Journal of Solids & Structures 2014; 11: 1163-1189. [13] Yang YT, Fishbain B, Hochbaum DS, et al. The Supervised Normalized Cut Method for Detecting, Classifying, and Identifying Special Nuclear Materials. Informs Journal on Computing 2014; 26: 45-58. [14] Liang XL, Lu L and Zhou HM.Alternative energy in the energy network. Smart Grid 2015; 3: 1192-1196. [15] Yan QY, Zhu ML and Tang XF.Electrical Energy Alternative Research Based on the Cost Utility Analysis. Operations Research and Management Science 2015; 24: 176-183. [16] Dong X, Zhu YG, Wang F, et al. The future development model of Hubei area under the implementation of electric energy substitution strategy. Applied Energy Technology 2015; 11: 38-40. [17] Liang J and Zhang XL. Analysis on spatial distribution characteristics of urban energy consumption among capital cities in China. Resources science 2009; 31: 2086-2092. [18] Han LN. Research on energy structure in China. Ph.D. Dissertation. ShangHai: Shanghai Jiao Tong University. 2007.