Electric Buses Mark Poulton, Vehicle Technology Manager Surface Strategy & Planning London Electric Vehicle Partnership meeting City Hall, 7 July 2014

Contents  TfL’s electric bus research priorities  Trials of pure electric buses – • Routes 507 & 521

• Route H98 • Route 312 • Early results and feedback

• CO2 impacts • Issues / challenges

 Advanced technology demonstration – • Range-extended diesel-electric (plug-in) hybrid buses • High-power wireless charging

Research priorities for e-buses  Pure electric buses: to understand operational viability & durability of battery technology – • • • • •

realistic vehicle range recharging times charging strategies passenger / weight trade-off battery degradation

 Plug-in hybrid or range-extended diesel-electric hybrid buses: to investigate practicality & operational benefits and to quantify potential CO2 savings over existing hybrid technology  Opportunity charging: investigate the potential of wireless charging systems and fast / rapid charging for extending range and maximising availability

Electric bus trials in London  TfL, via bus operators, is undertaking a number of electric bus trials during 2014 and beyond  These will involve 8 single deck pure electric buses on four routes in both central London and outer suburbs

Routes 507 & 521 – BYD ebus  Two 12-m BYD ebuses operating alongside conventional diesel buses (Mercedes-Benz Citaro), since December 2013  507 service runs between Victoria and Waterloo stations: • route length 2.24km; running time ~ 20 minutes

 521 service runs between London Bridge and Waterloo stations: • route length 3.50km; running time ~ 35 minutes

Vehicle requirements – routes 507 & 521 Route:

507 MF Early Morning

50

05:30 07:30 33

45 40

Ref: MF Morning Peak 07:30 09:30 46

31745 MF Morning 10:00 12:00 36

MF MF Afternoon Evening Peak 13:00 16:30 15:30 19:00 21 43

MF Early Evening

MF Late evening

19:30 21:00 23

21:00 23:00 9

35 30 25 20 15 10 5 0 05:30 - 07:30

07:30 - 09:30

10:00 - 12:00

13:00 - 15:30

16:30 - 19:00

19:30 - 21:00

21:00 - 23:00

MF Early Morning

MF Morning Peak

MF Morning

MF Afternoon

MF Evening Peak

MF Early Evening

MF Late evening

BYD ebus monitoring & performance data  A snapshot of typical average daily charging, operational hours and performance monitoring data for two periods since February 2014: Charge duration

Daily operating hours (on road)

5hrs

9hrs

Daily battery SOC used

Daily mileage

%

Daily energy consumption kWh

Specific energy consumption kWh per mile

42

126

66

1.91

103

1.69

Some Examples of Longer

7hrs

13hrs

57

Operating

174

Hours

 Aim of this trial is to: • gain experience, knowledge and build confidence to plan the optimised deployment of electric buses in London • monitor performance to validate the manufacturer’s claims of an urban operating range of 250 km (156 miles) on a single charge • evaluate the potential fuel cost savings (75% claimed)

BYD ebus - London specifications Dimensions & Masses Length

12000

mm

Width

2550

mm

Kerb Weight

13800

kg

Range Urban Conditions

250

km

Battery Voltage Capacity

540

V

600

Ah

324

kWh

Charging System Standard Charge

5 (60kW)

h

Passenger Carrying Capacity Comparisons Make/Model

Seated

Standing

Wheelchair

Total

Citaro

21

75

0

96

BYD

17

39

0

56

Route H98 – Optare MetroCity  Four 10.6-m Optare MetroCity pure electric buses entered service on route H98 (HayesHoulslow) on 31 May 2014, alongside conventional diesel ADL Enviro200 buses  Vehicles are initially being deployed in a varied operational pattern to gain experience of capabilities  Recharging by both rapid DC (~ 1 hour) and slower (overnight 6-8 hours) techniques

CO2 impacts*  BYD ebus (vs 12-m Euro V Citaro) • Average energy consumption: 1.8 kWh/mile (1.12 kWh/km) • Average specific CO2 emissions: 528 g/km

 Optare MetroCity (vs 10.2-m Euro V Enviro200) • Average energy consumption: 1.2 kWh/mile (0.75 kWh/km) • Average specific CO2 emissions: 352 g/km

 TfL Euro V single deck diesel bus fleet average specific CO2 emissions: 938 g/km (tailpipe; WTW + c.15%) Pure electric single deck bus CO2 saving potential > 50% data; subject to verification & audit and based on 2012 UK grid carbon intensity factor, * preliminary including upstream emissions from production of fuels used in electricity generation, and for efficiency losses during electric vehicle charging and from electricity transmission and distribution (472.4 g/kWh)

Challenges for electric buses 1. Impact of ancillary loads (lights, HEVAC, air compressor, power steering, battery conditioning) reduces available range. During extreme weather these loads can be as much as the energy needed to propel the vehicle 2. Key to successful operation of electric buses is maximising utilisation and hours in operation and benefiting from reduced running costs. These can be achieved by:  Recharging during inter-peak period(s), but this can impact on TVR / PVR ratio, or  Opportunity (rapid) charging, either through DC chargers (plug-in charge points, overhead catenary or underground contactors) or by wireless chargers embedded in the road

Wireless energy transfer (Induction Charging)  High power wireless charging at strategic transport interchanges could be a key enabling technology for bus electrification (and other fleet applications, such as taxis)

 This technology is not yet fully commercialised and is being trialled by TfL as part of an 8-city European demonstration project (‘ZeEUS’)

TfL’s wireless charging bus demonstration project  TfL is to demonstrate “plug-in” series hybrid (or rangeextended electric) buses  Induction charging or ‘Inductive Power Transfer’ used to provide opportunity charging  Infrastructure is to be installed in TfL bus stations at either end of demonstration route(s)  Objective is to operate on grid electricity as much as possible; battery will provide a significant amount of the energy required  Flexibility of hybrid power-train retained

London ZeEUS demonstration – route 69

Route 69     

11 km km (~ (7 7miles) in length miles) long Running time ~40-50 minutes Layover time up to 15 minutes Running time ~40-50 minutes PVR 15-18 vehicles Busy, congested Layover time up bus stations to 14 minutes

 PVR 15-18 vehicles

 TfL will set a route-specific performance target (EV / grid energy %, fuel saving …)

Induction charging infrastructure  Ground stations are solid state; no moving parts  Inductive power transfer is initiated automatically when the vehicle is correctly aligned

 Infrastructure is waterproof, vandal-resistant and able to be remotely monitored  External requirements are a control unit and cooling system

Conclusions  Mayor’s climate change targets are driving TfL’s CO2 emissions reduction strategies  In addition to trialling new technology, TfL has already achieved operational improvments and retrofitted vehicles to reduce CO2 and improve air quality  Electric buses offer the potential to move towards zero emissions operation in future, in conjunction with policy levers such as the proposed ULEZ  Trials and demonstrations are to gain experience, knowledge and build confidence to plan the optimised deployment of electric buses in London  Infrastructure requirements (& investment) key to many future solutions – electric vehicles, range-extended/plug-in hybrids, hydrogen fuel cells ...