Overcoming the Operational Challenges of Electric Buses: Lessons Learnt from China
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Overcoming the operational challenges of electric buses: lessons learnt from China New energy bus adoption in China • China’s battery electric buses (abbreviated for “e-bus” thereafter) totaled 324,231 in 2019, accounting for around a half of the bus fleet—becoming the mainstreamed bus technology. China’s bus fleet composition in 2015 China’s bus fleet composition in 2019 Others Gasoline Ethanol Ethanol Gasoline 0% 2% 1% 0% 0% 1% Trolley PHEV+HEV 9% PHEV+HEV Diesel 0% BEV 12% 17% Dual fuel 6% LPG 3% 0% Diesel 45% Natural gas 22% Natural gas 33% BEV 47% Dual fuel Trolley 1% LPG 0% 1% Source: MOT 2020. New energy bus adoption in China (cont.) Top 15 cities with the largest number of new energy buses on street (in 1,000 buses, including BEV + PHEV) as of 2019 Even distribution of new energy buses (or e-buses) across Chinese cities, regardless of city sizes & economic development stages, Harbin Cold climate operating temperatures, and landscapes. Chongqing Hilly terrain Foshan 3rd or 4th tier Chinese city Geographic distribution of e-buses in China Jinan Hangzhou Chengdu Zhengzhou Jining 3rd or 4th tier Chinese city Dongguan Xi'an Shanghai Changsha Beijing Cold climate Guangzhou Shenzhen 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 Source: MOT 2020. WRI 2020 Setting the scene: charging technologies BEV’s charging technologies converge to slow & fast charging: • Slow charge: depot charge Examples: Shenzhen (battery range 250km) • Fast charge: terminal charge ( recharge every 1-3 cycles) Slow Charge Fast Charge Battery Swap Example: Guiyang (battery range 90~120km) Low battery ranges and high Long charging hours Frequent recharging needs infrastructure requirement • Opportunity charge(pantograph/trolley): costly infrastructure investment & lack of operational flexibility • Battery swap: extra battery reserve will drive up the cost & large land occupation • Wireless charge: costly technology, energy On route-pantograph Opp. Charge-cable Wireless charge loss, and safety concerns Costly infrastructure High infrastructure requirement Costly technology Source: WRI 2019 Setting the scene: lengths of e-buses Articulated buses The mainstreamed e-buses in China are 8~12meter buses, with a limited number of articulated e-buses and electric double deckers. Annual sales ratios of e-buses with different lengths 100% 90% 80% 70% 60% Double deckers 50% 40% 30% 20% 10% 0% 2015 2016 2017 2018 2019 below 6m between 6m ~ 8m between 8m ~ 10m between 10m ~ 12m above 12m Source: CATARC 2020 Research question: • The total cost of ownership of e-bus (8year service life) is already is lower than that of diesel bus. • The central question is no longer how to lower the TCO of e-buses to accelerate the adoption, but improve the operation efficiency. Total cost of ownership of e-bus in China (10meter bus, in 10,000RMB) 2016 120 Prices of e-buses in comparison to diesel buses (in 1000 USD) 2018 161 2020 156 bus (with subsidy) (with bus - E 纯电动(各类补助) 2016 224 2018 202 2020 168 bus (no subsidy) (no bus - E 纯电动(无补贴) 车 207 燃油 Diesel Diesel bus 0 50 100 150 200 250 车辆单价Vehicle 8年运营成本8-yr operation 8年维护成本Maintenance price cost cost Source: WRI 2019, WRI 2020 Research Method • E-bus “big data” analysis Collaborated with National New Energy Vehicle Big Data Lab to gather city-level e-bus fleet’s operation statistics of 15 Chinese cities based on e-bus On-Board Diagnostic data(OBD), including city-level vehicle availability, daily operating mileages, and statistics of charging behaviours. • Survey through purposive sampling Conducted a survey to bus operators and transit bureau officials in 10 sampled cities to triangulate the big data analysis (use Bootstrap sampling to balance the sample size of each city). City Representativeness • Different levels of e-bus adoption, development stages, and environment like temperature and landscape • E-bus charging technology deployed • Major OEMs and market landscape Sampled cities with different levels of e-bus adoption Geographical locations of the sampled cities (% of e-buses in the fleet) Yellow bar is the sampled city and their e-bus adoption levels City Representativeness: Brand coverage • China’s domestic e-bus market is fragmented. Although it increases the market competition and lower the prices of e-buses, it also creates the challenges of bus operators to discern e-buses’ technical performances and qualities. Top 10 OEMs with the largest annual sales as of 2019 The brand coverage of the selected sampled cities Shenzhen Zhengzhou Nanjing Hangzhou Beijing Qingdao Zhuzhou Others Yutong √ √ 21% Yutong 25% BYD √ √ Zhongtong √ CRRC Times √ King Long-Nanjing 2% Zhuhai Guangtong √ √ Ankai BAIC Futian √ 2% Xiamen Golden √ King Long-Xiamen Dragon 4% King Long-Xiamen √ BYD Xiamen Golden 16% Ankai √ Dragon King Long-Nanjing √ √ 4% BAIC Futian CRRC Others √ √ 5% Times Zhongtong Zhuhai Guangtong 7% 8% 6% Source: CATS 2019 Source: WRI 2019 City Representativeness: Charging technologies • The way to operate slow charging e-buses differs from that for fast charging e-buses. • Many sampled cities rely on slow charging, but there are also quite a few cities deploying fast charging. Hybrid cases also exist (like Nanjing and Suzhou). Charging technologies and e-bus operation schemes of the sampled cities Slow charging operation Fast charging operation Battery range Above 120km Below 120km (rough) Fast charging Daytime 0~1 recharge 2~4 recharge recharging 1~2hour charging sessions 10~20 minute charging sessions 3C Overnight Yes Sometimes, no charging Above 1.6C Slow charging Sampled Shenzhen, Zhengzhou, Beijing, Guiyang, Chengdu, Chongqing, 1.6C cities Hangzhou, Shanghai, Wuhan, Jinan Blow 1.6C Qingdao, Zhuzhou Yichang 0 Source: WRI 2019 Evaluating city-level e-buses’ operation efficiency • Pre-condition: Bus electrification will not affect existing operation like route alignment or timetables. • Operation efficiency indicators 1. (City-level) average daily vehicle availability 2. (City-level) average daily mileage 3. (Route-level or city-level) replacement rate between diesel buses and electric buses 1. Vehicle availability Low vehicle availability rates due to: 1. Vehicle downtime 2. Back-up vehicles not deployed when passenger demand is low 3. Unfit for operation resulting from limited ranges and etc. 4. Issues with OBD data reporting Average availability rates of e-buses for 15 cities in summer workdays 90% 84% 79% 79% 80% 77% 73% 71% 68% 70% 65% 64% 62% 60% 60% 56% 49% 50% 42% 40% 30% 24% 20% 10% 0% Chengdu成都市Zhuzhou株洲市Chongqing重庆市 宜昌市Yi 贵阳市Gui 杭州市Hang 济南市Jinan 上海市Shang Shenzhen深圳市 青岛市Qing 郑州市Zheng 北京市Beijing 南京市Nan 武汉市Wuhan 襄阳市Xiang Chang yang zhou hai dao zhou jing yang Source: WRI 2019 2. Daily mileage The national average daily mileage of e-buses was 123 kilometers, nearly half of that for diesel buses. Mileage of diesel buses vs. e-buses ranked by the top 10 provinces with the Average daily operating mileage in China highest e-bus mileages (km) (2016-2018) (km) 200 Guangdong 169 140 Shanghai 216 119 123 158 120 229 Gansu 155 97 100 200 Chongqing 150 80 182 Guizhou 148 60 164.16 Xizang 144 40 154.92 Qinghai 144 20 181 Shanxi 143 0 200 Hubei 138 2016 2017 2018 195 Zhengjiang 137 0 50 100 150 200 250 Daily operating mileage of diesel bus Source: WRI 2019, MOT 2019 Daily operating mileage of e-bus 2. Daily mileage (cont.) Sizes of e-buses deployed and routes typically targeted for electrification (survey result) Unit: bootstrapped sample size Source: WRI 2019 Daily mileage (km) Source: WRI 2019 3. Route-level replacement rate between diesel buses and e-buses Source: WRI 2019 3. Route-level replacement rate between diesel buses and e-buses (cont.) • Options to replace an all-day diesel bus with e-buses 6:00am 22:00pm An all-day diesel bus Diesel #1 (260km) 6:00am 14:00pm 22:00pm 1:2 (e-bus) replacement E-bus #1 (130km) E-bus #2 (130km) 6:00am 17:00pm 22:00pm 2:3 (e-bus) replacement E-bus #1 (190km) E-bus #2 (80km) 6:00am 19:00pm 22:00pm Efficient replacement E-bus #1 (220km) E-bus #2 (40km) Source: WRI 2019 Factors that affect e-bus’s operational inefficiency Unit: sampleUnit: bootstrappedsize Source: WRI 2019 1.What technical specifications would be required from e-buses that won’t affect operation efficiency? • Slow charging operation (depot charging): • Fast charging operation (terminal charging): • Battery range: 120~280 km (depending on route • Battery range: 60~120 km (depending on route length and daily operating mileage) length, layover time, terminal points, and charger availability) • Daytime charging: 0~1 times, 1~1.5 hour duration • Daytime charging: 2~4 times, 10~20min duration for for each session each session • Night-time charging: a must • Night-time charging: no need • Example: Shenzhen • Example: Guiyang Battery range Battery range & C-rate Unit: bootstrapped sample size sample bootstrapped Unit: Unit: bootstrapped sample size sample bootstrapped Unit: Source: WRI 2019 1.What technical specifications would be required from e-buses that won’t affect operation efficiency? (con.t) • Fast-charging case 1: ample chargers • One terminal point Route length: 15km • 15min recharge after each roundtrip (30km) • Range: above 50km Terminal point • Fast-charging case 2: limited chargers • One terminal point Route length: 15km • 15min recharge every two roundtrips (60km) Terminal point • Range: above 100km • Fast-charging others: Terminal point • Two terminal points Route length: 20km • Different route lengths Terminal point • Range: above 83km Assume the maximum DOD is 40%. Source: WRI 2019 1.What technical specifications