- Email: [email protected]
Potential distributions of electric vehicle secondary used batteries for frequency regulation in Europe
Available online at www.sciencedirect.com
ScienceDirect
Availableonline onlineatatwww.sciencedirect.com www.sciencedirect.com Available Energy Procedia 00 (2018) 000–000
ScienceDirect ScienceDirect
www.elsevier.com/locate/procedia
Energy (2019) 000–000 394–399 EnergyProcedia Procedia159 00 (2017) www.elsevier.com/locate/procedia
Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2018, 29–30 September 2018, Rhodes, Greece The 15th International Symposium on District Heating and used Coolingbatteries Potential distributions of electric vehicle secondary for frequency regulation in Europe Assessing the feasibility of using the heat demand-outdoor a b,* Nassar , Koji Tokimatsua,district Muhammad Aziz temperature Eslam function for a long-term heat demand forecast a
Dept. Transdisciplinary Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226a,b,c a a b c c 8503, Japan b Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan a IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal b Veolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France c Département Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France
I. Andrić
*, A. Pina , P. Ferrão , J. Fournier ., B. Lacarrière , O. Le Corre
Abstract
The number of electric vehicles (EVs) has been rapidly increasing, leading to the importance to predict the most beneficial way to Abstractthem with electrical grids. Continuous charging and discharging of EVs make their batteries degrade, resulting in a need integrate for them to be replaced. Therefore, many researchers have been discussing possible utilization of the secondary used batteries, as District heatingcapacities networkscan areassist commonly addressedincluding in the literature one ofand the providing most effective solutions forfordecreasing the their remaining in grid services, peak loadasshaving ancillary services the grids. In greenhouse emissions the building These require high investments which are returned through the heat this study, thegas future supplyfrom of secondary usedsector. batteries fromsystems the selected European countries is evaluated. In addition, a possible sales. Due from to the conditions buildingregulation renovation policies, demandThe in results the future decrease, distribution onechanged countryclimate to another based onand frequency needs is alsoheat observed. showcould a remarkable prolonging the investment return period. relation between grids with high renewable energy integration and need for batteries for frequency regulation. The main scope of this paper is to assess the feasibility of using the heat demand – outdoor temperature function for heat demand ©forecast. 2019 The Authors. Published Ltd. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 Copyright © 2018 Elsevier Ltd. by AllElsevier rights reserved. This is an open accessinarticle under the CC-BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) buildings that vary both construction period andthetypology. weatherofscenarios (low,Energy medium, high) and and threeForum, district Selection and peer-review under responsibility of scientificThree committee the Applied Symposium Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were Renewable Energy Integration with REM 2018. Renewable Energy Integration withMini/Microgrids, Mini/Microgrids, REM 2018. compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed thatsecondary when only weather change is considered, the margin of error could be acceptable for some applications Keywords: Electric vehicle, used batteries, renewable energy, frequency regulation, energy management (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% 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. Corresponding author. Tel.: +81-3-5734-3809; fax: +81-3-5734-3559.
*
© 2017address: The Authors. Published by Elsevier Ltd. E-mail [email protected] Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. Keywords: Heat demand; Forecast; Climate change 1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2018. 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. 1876-6102 © 2019 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. This is an open access article under the CC-BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2018. 10.1016/j.egypro.2018.12.070
2
Eslam Nassar et al. / Energy Procedia 159 (2019) 394–399 Eslam Nassar/ Energy Procedia 00 (2018) 000–000
395
Nomenclature EV PV BEV PHEV
electric vehicles photovoltaics battery electric vehicle power hybrid electric vehicle
1. Introduction High diffusion rate of renewable energy resources in the electrical grid may result in instability in production as well as high grid frequency fluctuations. Nevertheless, the growth rate of electric vehicles (EVs) market is phenomenal, and it is not only shaping the future of mobility, it also gives a great impact on both energy consumption and generation. Unlike internal combustion engines, EVs solely depend on electricity for driving their electric motors, thus their high capacity battery packs are capable of being charged with enough power to achieve the desired range and functionality of the car. While high growth rate might cause additional load on the electric grids during charging times, there are wide areas to utilize EV and their secondary used batteries in the energy markets [1]. Among many services, frequency regulation of electric grids is considered to have high potential, offering a complementary system that overcomes undesirable impacts of renewable energy resources on the grid [2]. Among car manufacturers, the reuse of retired batteries from EVs is being seriously investigated. After the battery capacity reaches 70-80% of its initial capacity, it needs to be replaced. Some experts anticipate them to be used to store and balance the renewable energy or grid ancillary services, such as frequency regulation, as they still retain significant capacity [3]. Further, it is also considered important to estimate what kind of impact that the growing number of residential battery storage systems has on the market, the electricity sector, and policy-making. Finally, Many studies have been addressing different applications for utilizing secondary batteries, however no clear correlation between the use of secondary batteries and other available power storage for frequency regulations was identified, and estimating market need among high EV adoption countries have been not properly analyzed, Therefore, in order to forecast the market shape, it is necessary to correlate between frequency regulation using EV, Renewable energy causing fluctuation, secondary used batteries and other available power storage. The research objective of this study is to estimate the best distribution of secondary used EV batteries among several countries, that can maximize the utilization of their energy storage capacity for frequency regulation. Specifically, the capacity of different renewable energy resources and their impact on frequency instability is analyzed in 8 European countries. Then the EV markets are evaluated in order to predict their used batteries potential while comparing secondary used batteries with other pre-existing energy storages in the selected countries. Lastly, an index was proposed and tested in the chosen countries, in order to determine which countries can be a potential distributor for secondary batteries in the future 1.1. Countries selection The following 8 European countries were chosen for this study: France, Germany, Denmark, Finland, Norway, Sweden, and Netherlands. These countries are members of the Electric vehicle initiative (EVI) The selection was based on their high adoption rates of EV during the past 5 years. Another factor for choosing countries was Renewable energies share; the 8 countries are rapidly progressing with increasing their electricity generation from renewable energy resources, especially hydro, wind and solar systems. As shown in Fig. 1, Norway is ahead of all European countries in terms of number of registered BEV and the highest in adopting BEV. In 2015, electric vehicles had a 22 % market share in Norway [4]. Policies, incentives, and infrastructure play a crucial role in the increase of EV market shares in countries [5]. 1.2. Renewable energy generation In 2016, Norway set a new electricity production record of 149 TWh. Norway has the highest share of electricity generation from renewable energy resources in Europe. Hydropower alone accounts for 96 % of Norwegian power
Eslam Nassar et al. / Energy Procedia 159 (2019) 394–399 Author name / Energy Procedia 00 (2018) 000–000
396
3
120000
120%
100000
100%
80000
80%
60000
60%
40000
40%
20000
20%
0
%
MW
supplies [6]. France has a low-carbon energy mix, owing to the main role of nuclear energy, which accounts for 73% of electricity generation [7]. In Germany, the high capacity generated power from renewable resources contributes to around 23% of its total electricity generation. On the other hand, the Netherlands produces only 13% of its energy generation using renewable energy, the major generation capacity is from fossil fuels. Generation from coal, gas and oil addresses to 82% of the total electricity generation. While most of the renewable energy generation comes from wind and biofuels [8].
0%
RE share (%)
RE capacity (MW)
Fig. 1. Renewable energy share and capacity Table 1. Renewable energy generation capacity, energy storage capacity, and BEV number Country
RE share
RE capacity (MW)
Available energy storage capacity (MWh)
Number of registered BEV (2013-2017)
France
19%
44304
5831
83658
Germany
32%
101606
7487
61405
UK
25%
32695
3303
43100
Netherlands
13%
6343
18
20499
Sweden
65%
23053
10
11790
Norway
97%
32717
967
109371
Denmark
54%
6106
3
8483
Finland
33%
4850
3
1204
1.3. BEV and PHEV trends As shown in Figs. 2 and 3, number of registered BEV and PHEV has been rapidly increasing during the last 5 years, leading to an increase in the total market share of electric cars in the respective countries [9]. Many parameters have led to the increase of the market share, from continuous advancement in EV technology and features, reduction in battery price, improved battery capacity contributing to longer drive ranges, encouraging policies, incentives and tax exemptions for EV owners to increasing of charging stations [10][11].
4
Eslam Nassar et al.Procedia / Energy 00 Procedia (2019) 394–399 Eslam Nassar/ Energy (2018)159 000–000
397
35000 30000 25000 20000 15000 10000 5000 0
50000 40000 30000 20000 10000 0
2013
2014
2015
2016
2017
2013
Fig. 2 Registered PHEV (2013-2017)
2014
2015
2016
2017
Fig. 3 Registered BEV (2013-2017)
1.4. EV secondary batteries capacity and uses Market analysis shows that the capacity of commercial BEV battery for passenger cars ranges from 16 kWh for the small-sized Mitsubishi i-MiEV with a driving range of about 85 km, to 100 kWh for the brand-new Tesla S 100D with a driving range up to 539 km. EV batteries need to be replaced when their efficiency drops to 80%; at which point, the EV battery cannot provide a sufficient power to the car, impacting the driving range [12]. Most previous studies have assumed a fixed EV battery lifespan of either 8 or 10 years under normal operating conditions. This implies that the user has avoided overcharging; aggressive driving, which can lead to rapid discharge and more frequent charging; and also operate at high temperatures [13]. Potential uses of secondary batteries are being thoroughly investigated in research. There is potential for secondary batteries to be used in load leveling and shifting the peak hours to reduce the grid load [14] or to add more benefits if it can be used for voltage and frequency regulations [15]. 1.5. Frequency fluctuation per energy source The impact of electricity generation resources on the frequency fluctuation of the grid is measured by inertia H(S). The higher the inertia constant, the better the system can reduce the rate of change of frequency after a significant drop in generation. Inertia has significant impact aspect for conventional generators that help in the inertial response for frequency control [16]. PV systems are connected to the grids through inverters and motors are encountered in the generation process. Therefore, unlike other resources such as thermal power, wind, hydro or nuclear, PV systems have zero inertia. The total grid inertia gets very low in case of high PV penetration, which leads to severe disturbance in the frequency of grid [17]. In order to estimate renewable energy generation resources impact scenarios in each country, the average value of inertia constants was used. Table 2. Inertia constants per generation type Production type
H(S)
PV
0
Hydro
3
Wind
4
Coal
6
CCGT
6.5
Eslam Nassar et al. / Energy Procedia 159 (2019) 394–399 Author name / Energy Procedia 00 (2018) 000–000
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5
2. Calculation method Grids with high penetration of renewable energy resources are more likely to encounter higher frequency fluctuation. Therefore, in this research, we tried to forecast the maximum benefits from EV secondary used batteries as a source for frequency regulation. The aim of the study is to observe the best distribution of secondary batteries that can happen between countries with a high share of EV and countries with high reliance on renewable energy resources. In addition, the available capacity of other installed energy storages was taken into consideration. Currently operating energy storages technologies for frequency regulation are hydrogen storage, lithium-ion battery, lead-acid battery and Electro-chemical. In order to estimate possible distributions for EV secondary batteries among the selected countries, a distribution index was created based on the relation between the actual number of registered BEV, available energy storage capacity, and renewable energy resources. α is estimated from the inertia constants of each renewable resource. While PHEV is not considered due to their relatively lower capacity compared with BEV. For estimating the weight of frequency fluctuation for each country, a factor α was calculated based on Inertia H(S) for each power resource. ݔ݁݀݊ܫൌ
ாሺ௨ሻାௌ௧ሺெௐሻ ோா௨௬ሺெௐሻ
ܴ ݇݊ܽݎݕܿ݊݁ݑݍ݁ݎ݂ܧൌ ߙଵ ܵ ݎ݈ܽ ߙଶ ݎ݀ݕܪ ߙଷ ܹ݅݊݀ ߑଵଷഀ ൌ ͳ
(1) (2) (3)
3. Results and discussion Fig. 4 shows the calculated EV secondary battery distribution index. The resulted index shows the weight of each country as a distributor of the secondary used battery; high index countries are more likely to distribute batteries to other countries having a low index. Also, it is concluded that there is a big gap between high index countries, such as Norway, the Netherlands, and France, compared to low index countries, such as Sweden, Germany, and Finland. Therefore, the need of using EV secondary battery for regulating the frequency would be higher in lower index countries. In that case, we can propose the distribution of the retired EV batteries from countries with higher index to the countries that have a lower index and a higher need. For example, Norway will have a high rate of retired EV batteries due to their progressive adoption of EV. While in France and Netherlands, the share of renewable energy generation is not as high, resulting to a highly stable grid, it is possible for the secondary used batteries in France or Norway after their retirement to be distributed to Finland, Sweden or Germany. 20 15 10 5 0
Fig. 4. EV secondary battery distribution index
The high number of secondary used EV batteries have high potential to be utilized for ancillary services, providing services including frequency regulation. The availability and need for secondary batteries for frequency regulation can vary from one country to another based on many factors. In this research, we nominated some of the main factors
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Eslam Nassar et al. / Energy Procedia 159 (2019) 394–399 Eslam Nassar/ Energy Procedia 00 (2018) 000–000
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for estimating the need of different countries to utilize secondary used EV batteries. Distribution between countries can occur based on their need for using secondary batteries for frequency regulation. Reusing secondary batteries in other applications, such as an energy storage for peak load shaving, has also great potential. Other factors to be encountered in the future can be the disposal cost of batteries in each country, which can negatively impact the adoption rate and also PHEV. 4. Conclusion High spread rate of EV batteries will lead to a high number of secondary used EV batteries. Therefore, these batteries have a high potential to be used for frequency regulation. Availability and need of secondary batteries for frequency regulation can vary from one country to another based on many factors. In this research, we selected some of the main parameters in order to estimate the future supply and need trends for the batteries. Because reusing secondary batteries has a great potential, the distribution between countries should occur based on their need for using secondary batteries for frequency regulation or other services. Other factors to be encountered in the future can be the disposal cost of battery in each country, which can negatively impact the adoption rate, also PHEV numbers and participation in vehicle-to-grid. References [1]
M. Aziz, T. Oda, T. Mitani, Y. Watanabe, and T. Kashiwagi, “Utilization of electric vehicles and their used batteries for peak-load shifting,” Energies, vol. 8, no. 5, pp. 3720–3738, 2015.
[2]
M. Aziz, T. Oda, and M. Ito, “Battery-assisted charging system for simultaneous charging of electric vehicles,” Energy, vol. 100, pp. 82–90, 2016.
[3]
R. Madlener and A. Kirmas, “Economic Viability of Second Use Electric Vehicle Batteries for Energy Storage in Residential
[4]
“Norway | EAFO.” [Online]. Available: http://www.eafo.eu/content/norway. [Accessed: 12-Aug-2018].
Applications,” Energy Procedia, vol. 105, pp. 3806–3815, 2017. [5]
S. Shepherd, P. Bonsall, and G. Harrison, “Factors affecting future demand for electric vehicles: A model based study,” Transp. Policy, vol. 20, pp. 62–74, Mar. 2012.
[6]
“Electricity production - Energifakta Norge.” [Online]. Available: https://energifaktanorge.no/en/norskenergiforsyning/kraftproduksjon/. [Accessed: 13-Aug-2018].
[7]
“Database - Eurostat.” [Online]. Available: http://ec.europa.eu/eurostat/web/energy/data/database?p_p_id=NavTreeportletprod_WAR_NavTreeportletprod_INSTANCE_QAMy7P e6HwI1&p_p_lifecycle=0&p_p_state=normal&p_p_mode=view&p_p_col_id=column-2&p_p_col_count=1. [Accessed: 09-Aug2018].
[8]
“DOE Global Energy Storage Database.” [Online]. Available: http://www.energystorageexchange.org/. [Accessed: 13-Aug-2018].
[9]
“European Alternative Fuel Observatory | Countries.”
[10]
A. Keeli and R. K. Sharma, “Optimal use of second life battery for peak load management and improving the life of the battery,” 2012
[11]
O. Van Vliet, A. Sjoerd Brouwer, T. Kuramochi, M. Van Den Broek, and A. Faaij, “Energy use, cost and CO 2 emissions of electric
[12]
“ANALYSIS OF THE COMBINED VEHICLE-AND POST-VEHICLE-USE VALUE OF LITHIUM-ION PLUG-IN-VEHICLE
[13]
P. W. Gruber, P. A. Medina, G. A. Keoleian, S. E. Kesler, M. P. Everson, and T. J. Wallington, “Global Lithium Availability,” J. Ind.
IEEE Int. Electr. Veh. Conf., pp. 1–6, 2012. cars,” J. Power Sources, vol. 196, pp. 2298–2310, 2010. PROPULSION BATTERIES,” 2012. Ecol., vol. 15, no. 5, pp. 760–775, Oct. 2011. [14]
M. Aziz, T. Oda, A. Morihara, T. Murakami, and N. Momose, “Utilization of EVs and their used batteries in factory load leveling,” 2014 IEEE PES Innov. Smart Grid Technol. Conf. ISGT 2014, 2014.
[15]
R. Faria et al., “Primary and secondary use of electric mobility batteries from a life cycle perspective,” J. Power Sources, vol. 262, pp.
[16]
A. Ulbig, T. S. Borsche, and G. Andersson, “Impact of Low Rotational Inertia on Power System Stability and Operation.”
[17]
A. Mills et al., “Understanding Variability and Uncertainty of Photovoltaics for Integration with the Electric Power System,” 2009.
169–177, Sep. 2014.
ScienceDirect
Availableonline onlineatatwww.sciencedirect.com www.sciencedirect.com Available Energy Procedia 00 (2018) 000–000
ScienceDirect ScienceDirect
www.elsevier.com/locate/procedia
Energy (2019) 000–000 394–399 EnergyProcedia Procedia159 00 (2017) www.elsevier.com/locate/procedia
Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2018, 29–30 September 2018, Rhodes, Greece The 15th International Symposium on District Heating and used Coolingbatteries Potential distributions of electric vehicle secondary for frequency regulation in Europe Assessing the feasibility of using the heat demand-outdoor a b,* Nassar , Koji Tokimatsua,district Muhammad Aziz temperature Eslam function for a long-term heat demand forecast a
Dept. Transdisciplinary Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226a,b,c a a b c c 8503, Japan b Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan a IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal b Veolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France c Département Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France
I. Andrić
*, A. Pina , P. Ferrão , J. Fournier ., B. Lacarrière , O. Le Corre
Abstract
The number of electric vehicles (EVs) has been rapidly increasing, leading to the importance to predict the most beneficial way to Abstractthem with electrical grids. Continuous charging and discharging of EVs make their batteries degrade, resulting in a need integrate for them to be replaced. Therefore, many researchers have been discussing possible utilization of the secondary used batteries, as District heatingcapacities networkscan areassist commonly addressedincluding in the literature one ofand the providing most effective solutions forfordecreasing the their remaining in grid services, peak loadasshaving ancillary services the grids. In greenhouse emissions the building These require high investments which are returned through the heat this study, thegas future supplyfrom of secondary usedsector. batteries fromsystems the selected European countries is evaluated. In addition, a possible sales. Due from to the conditions buildingregulation renovation policies, demandThe in results the future decrease, distribution onechanged countryclimate to another based onand frequency needs is alsoheat observed. showcould a remarkable prolonging the investment return period. relation between grids with high renewable energy integration and need for batteries for frequency regulation. The main scope of this paper is to assess the feasibility of using the heat demand – outdoor temperature function for heat demand ©forecast. 2019 The Authors. Published Ltd. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 Copyright © 2018 Elsevier Ltd. by AllElsevier rights reserved. This is an open accessinarticle under the CC-BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) buildings that vary both construction period andthetypology. weatherofscenarios (low,Energy medium, high) and and threeForum, district Selection and peer-review under responsibility of scientificThree committee the Applied Symposium Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were Renewable Energy Integration with REM 2018. Renewable Energy Integration withMini/Microgrids, Mini/Microgrids, REM 2018. compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed thatsecondary when only weather change is considered, the margin of error could be acceptable for some applications Keywords: Electric vehicle, used batteries, renewable energy, frequency regulation, energy management (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% 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. Corresponding author. Tel.: +81-3-5734-3809; fax: +81-3-5734-3559.
*
© 2017address: The Authors. Published by Elsevier Ltd. E-mail [email protected] Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. Keywords: Heat demand; Forecast; Climate change 1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2018. 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. 1876-6102 © 2019 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. This is an open access article under the CC-BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2018. 10.1016/j.egypro.2018.12.070
2
Eslam Nassar et al. / Energy Procedia 159 (2019) 394–399 Eslam Nassar/ Energy Procedia 00 (2018) 000–000
395
Nomenclature EV PV BEV PHEV
electric vehicles photovoltaics battery electric vehicle power hybrid electric vehicle
1. Introduction High diffusion rate of renewable energy resources in the electrical grid may result in instability in production as well as high grid frequency fluctuations. Nevertheless, the growth rate of electric vehicles (EVs) market is phenomenal, and it is not only shaping the future of mobility, it also gives a great impact on both energy consumption and generation. Unlike internal combustion engines, EVs solely depend on electricity for driving their electric motors, thus their high capacity battery packs are capable of being charged with enough power to achieve the desired range and functionality of the car. While high growth rate might cause additional load on the electric grids during charging times, there are wide areas to utilize EV and their secondary used batteries in the energy markets [1]. Among many services, frequency regulation of electric grids is considered to have high potential, offering a complementary system that overcomes undesirable impacts of renewable energy resources on the grid [2]. Among car manufacturers, the reuse of retired batteries from EVs is being seriously investigated. After the battery capacity reaches 70-80% of its initial capacity, it needs to be replaced. Some experts anticipate them to be used to store and balance the renewable energy or grid ancillary services, such as frequency regulation, as they still retain significant capacity [3]. Further, it is also considered important to estimate what kind of impact that the growing number of residential battery storage systems has on the market, the electricity sector, and policy-making. Finally, Many studies have been addressing different applications for utilizing secondary batteries, however no clear correlation between the use of secondary batteries and other available power storage for frequency regulations was identified, and estimating market need among high EV adoption countries have been not properly analyzed, Therefore, in order to forecast the market shape, it is necessary to correlate between frequency regulation using EV, Renewable energy causing fluctuation, secondary used batteries and other available power storage. The research objective of this study is to estimate the best distribution of secondary used EV batteries among several countries, that can maximize the utilization of their energy storage capacity for frequency regulation. Specifically, the capacity of different renewable energy resources and their impact on frequency instability is analyzed in 8 European countries. Then the EV markets are evaluated in order to predict their used batteries potential while comparing secondary used batteries with other pre-existing energy storages in the selected countries. Lastly, an index was proposed and tested in the chosen countries, in order to determine which countries can be a potential distributor for secondary batteries in the future 1.1. Countries selection The following 8 European countries were chosen for this study: France, Germany, Denmark, Finland, Norway, Sweden, and Netherlands. These countries are members of the Electric vehicle initiative (EVI) The selection was based on their high adoption rates of EV during the past 5 years. Another factor for choosing countries was Renewable energies share; the 8 countries are rapidly progressing with increasing their electricity generation from renewable energy resources, especially hydro, wind and solar systems. As shown in Fig. 1, Norway is ahead of all European countries in terms of number of registered BEV and the highest in adopting BEV. In 2015, electric vehicles had a 22 % market share in Norway [4]. Policies, incentives, and infrastructure play a crucial role in the increase of EV market shares in countries [5]. 1.2. Renewable energy generation In 2016, Norway set a new electricity production record of 149 TWh. Norway has the highest share of electricity generation from renewable energy resources in Europe. Hydropower alone accounts for 96 % of Norwegian power
Eslam Nassar et al. / Energy Procedia 159 (2019) 394–399 Author name / Energy Procedia 00 (2018) 000–000
396
3
120000
120%
100000
100%
80000
80%
60000
60%
40000
40%
20000
20%
0
%
MW
supplies [6]. France has a low-carbon energy mix, owing to the main role of nuclear energy, which accounts for 73% of electricity generation [7]. In Germany, the high capacity generated power from renewable resources contributes to around 23% of its total electricity generation. On the other hand, the Netherlands produces only 13% of its energy generation using renewable energy, the major generation capacity is from fossil fuels. Generation from coal, gas and oil addresses to 82% of the total electricity generation. While most of the renewable energy generation comes from wind and biofuels [8].
0%
RE share (%)
RE capacity (MW)
Fig. 1. Renewable energy share and capacity Table 1. Renewable energy generation capacity, energy storage capacity, and BEV number Country
RE share
RE capacity (MW)
Available energy storage capacity (MWh)
Number of registered BEV (2013-2017)
France
19%
44304
5831
83658
Germany
32%
101606
7487
61405
UK
25%
32695
3303
43100
Netherlands
13%
6343
18
20499
Sweden
65%
23053
10
11790
Norway
97%
32717
967
109371
Denmark
54%
6106
3
8483
Finland
33%
4850
3
1204
1.3. BEV and PHEV trends As shown in Figs. 2 and 3, number of registered BEV and PHEV has been rapidly increasing during the last 5 years, leading to an increase in the total market share of electric cars in the respective countries [9]. Many parameters have led to the increase of the market share, from continuous advancement in EV technology and features, reduction in battery price, improved battery capacity contributing to longer drive ranges, encouraging policies, incentives and tax exemptions for EV owners to increasing of charging stations [10][11].
4
Eslam Nassar et al.Procedia / Energy 00 Procedia (2019) 394–399 Eslam Nassar/ Energy (2018)159 000–000
397
35000 30000 25000 20000 15000 10000 5000 0
50000 40000 30000 20000 10000 0
2013
2014
2015
2016
2017
2013
Fig. 2 Registered PHEV (2013-2017)
2014
2015
2016
2017
Fig. 3 Registered BEV (2013-2017)
1.4. EV secondary batteries capacity and uses Market analysis shows that the capacity of commercial BEV battery for passenger cars ranges from 16 kWh for the small-sized Mitsubishi i-MiEV with a driving range of about 85 km, to 100 kWh for the brand-new Tesla S 100D with a driving range up to 539 km. EV batteries need to be replaced when their efficiency drops to 80%; at which point, the EV battery cannot provide a sufficient power to the car, impacting the driving range [12]. Most previous studies have assumed a fixed EV battery lifespan of either 8 or 10 years under normal operating conditions. This implies that the user has avoided overcharging; aggressive driving, which can lead to rapid discharge and more frequent charging; and also operate at high temperatures [13]. Potential uses of secondary batteries are being thoroughly investigated in research. There is potential for secondary batteries to be used in load leveling and shifting the peak hours to reduce the grid load [14] or to add more benefits if it can be used for voltage and frequency regulations [15]. 1.5. Frequency fluctuation per energy source The impact of electricity generation resources on the frequency fluctuation of the grid is measured by inertia H(S). The higher the inertia constant, the better the system can reduce the rate of change of frequency after a significant drop in generation. Inertia has significant impact aspect for conventional generators that help in the inertial response for frequency control [16]. PV systems are connected to the grids through inverters and motors are encountered in the generation process. Therefore, unlike other resources such as thermal power, wind, hydro or nuclear, PV systems have zero inertia. The total grid inertia gets very low in case of high PV penetration, which leads to severe disturbance in the frequency of grid [17]. In order to estimate renewable energy generation resources impact scenarios in each country, the average value of inertia constants was used. Table 2. Inertia constants per generation type Production type
H(S)
PV
0
Hydro
3
Wind
4
Coal
6
CCGT
6.5
Eslam Nassar et al. / Energy Procedia 159 (2019) 394–399 Author name / Energy Procedia 00 (2018) 000–000
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5
2. Calculation method Grids with high penetration of renewable energy resources are more likely to encounter higher frequency fluctuation. Therefore, in this research, we tried to forecast the maximum benefits from EV secondary used batteries as a source for frequency regulation. The aim of the study is to observe the best distribution of secondary batteries that can happen between countries with a high share of EV and countries with high reliance on renewable energy resources. In addition, the available capacity of other installed energy storages was taken into consideration. Currently operating energy storages technologies for frequency regulation are hydrogen storage, lithium-ion battery, lead-acid battery and Electro-chemical. In order to estimate possible distributions for EV secondary batteries among the selected countries, a distribution index was created based on the relation between the actual number of registered BEV, available energy storage capacity, and renewable energy resources. α is estimated from the inertia constants of each renewable resource. While PHEV is not considered due to their relatively lower capacity compared with BEV. For estimating the weight of frequency fluctuation for each country, a factor α was calculated based on Inertia H(S) for each power resource. ݔ݁݀݊ܫൌ
ாሺ௨ሻାௌ௧ሺெௐሻ ோா௨௬ሺெௐሻ
ܴ ݇݊ܽݎݕܿ݊݁ݑݍ݁ݎ݂ܧൌ ߙଵ ܵ ݎ݈ܽ ߙଶ ݎ݀ݕܪ ߙଷ ܹ݅݊݀ ߑଵଷഀ ൌ ͳ
(1) (2) (3)
3. Results and discussion Fig. 4 shows the calculated EV secondary battery distribution index. The resulted index shows the weight of each country as a distributor of the secondary used battery; high index countries are more likely to distribute batteries to other countries having a low index. Also, it is concluded that there is a big gap between high index countries, such as Norway, the Netherlands, and France, compared to low index countries, such as Sweden, Germany, and Finland. Therefore, the need of using EV secondary battery for regulating the frequency would be higher in lower index countries. In that case, we can propose the distribution of the retired EV batteries from countries with higher index to the countries that have a lower index and a higher need. For example, Norway will have a high rate of retired EV batteries due to their progressive adoption of EV. While in France and Netherlands, the share of renewable energy generation is not as high, resulting to a highly stable grid, it is possible for the secondary used batteries in France or Norway after their retirement to be distributed to Finland, Sweden or Germany. 20 15 10 5 0
Fig. 4. EV secondary battery distribution index
The high number of secondary used EV batteries have high potential to be utilized for ancillary services, providing services including frequency regulation. The availability and need for secondary batteries for frequency regulation can vary from one country to another based on many factors. In this research, we nominated some of the main factors
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for estimating the need of different countries to utilize secondary used EV batteries. Distribution between countries can occur based on their need for using secondary batteries for frequency regulation. Reusing secondary batteries in other applications, such as an energy storage for peak load shaving, has also great potential. Other factors to be encountered in the future can be the disposal cost of batteries in each country, which can negatively impact the adoption rate and also PHEV. 4. Conclusion High spread rate of EV batteries will lead to a high number of secondary used EV batteries. Therefore, these batteries have a high potential to be used for frequency regulation. Availability and need of secondary batteries for frequency regulation can vary from one country to another based on many factors. In this research, we selected some of the main parameters in order to estimate the future supply and need trends for the batteries. Because reusing secondary batteries has a great potential, the distribution between countries should occur based on their need for using secondary batteries for frequency regulation or other services. Other factors to be encountered in the future can be the disposal cost of battery in each country, which can negatively impact the adoption rate, also PHEV numbers and participation in vehicle-to-grid. References [1]
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