resultados c40 en latinoamérica

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In partnership with: Hybrid – Electric Bus Test Program in Latin America Final Report ISSRC January 2013 Prepared by: International Sustainable Systems Research Center - ISSRC 605 South Palm Street, Suite C, La Habra, CA 90631, USA www.issrc.org

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Page 1: Resultados C40 en Latinoamérica

In  partnership  with:  

 

 

Hybrid – Electric Bus Test Program in Latin America

Final Report

ISSRC January 2013

Prepared by:

International Sustainable Systems Research Center - ISSRC 605 South Palm Street, Suite C, La Habra, CA 90631, USA

www.issrc.org

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In  partnership  with:  

 

 

Project Name: Hybrid Electric Bus Test Program in Latin America (HEBTP-LA) Implementing Agency: C40 - Clinton Climate Initiative (CCI) Tests performed by: International Sustainable Systems Research Center (ISSRC) This Report: Santiago Report (ISSRC-HEBTP-08) C40-CCI Contact Person: Manuel Olivera, LATAM Hybrid bus test program & City Director, Santiago D.C.: [email protected] ISSRC Contact Person: Mauricio Osses, [email protected]

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TABLE OF CONTENTS 1   INTRODUCTION .................................................................................................................... 1  

1.1   GENERAL BACKGROUND .................................................................................................... 1  1.2   ORGANIZATION OF THIS REPORT ........................................................................................ 1  1.3   GENERAL METHODOLOGY .................................................................................................. 1  1.4   ABOUT HYBRID & ELECTRIC BUS TECHNOLOGIES ............................................................ 4  

2   ENERGY PERFORMANCE AND DRIVING CYCLES .................................................... 6  2.1   FUEL AND ENERGY CONSUMPTION ..................................................................................... 6  

2.1.1   Rio de Janeiro ............................................................................................................. 7  2.1.2   Sao Paulo .................................................................................................................... 7  2.1.3   Bogota ......................................................................................................................... 8  2.1.4   Santiago ....................................................................................................................... 9  

2.2   DRIVING CYCLES .............................................................................................................. 10  2.2.1   Rio de Janeiro ........................................................................................................... 11  2.2.2   Sao Paulo .................................................................................................................. 11  2.2.3   Bogota ....................................................................................................................... 12  2.2.4   Santiago ..................................................................................................................... 13  

3   EXHAUST EMISSIONS AND ENERGY CONSUMPTION ............................................ 15  3.1   OVERALL RAW EMISSIONS RESULTS ................................................................................. 15  

3.1.1   Rio de Janeiro ........................................................................................................... 16  3.1.2   Sao Paulo .................................................................................................................. 17  3.1.3   Bogota ....................................................................................................................... 19  3.1.4   Santiago ..................................................................................................................... 20  

3.2   EMISSIONS BY ENERGY DEMAND SITUATIONS PER CITY ................................................. 22  3.2.1   Rio de Janeiro ........................................................................................................... 22  3.2.2   Sao Paulo .................................................................................................................. 25  3.2.3   Bogota ....................................................................................................................... 28  3.2.4   Santiago ..................................................................................................................... 31  

3.3   NORMALIZED EMISSIONS RESULTS .................................................................................. 34  3.3.1   Rio de Janeiro ........................................................................................................... 34  3.3.2   Sao Paulo .................................................................................................................. 36  3.3.3   Bogota ....................................................................................................................... 37  3.3.4   Santiago ..................................................................................................................... 39  

4   DISCUSSION AND CONCLUSIONS ................................................................................. 41  4.1   EXHAUST EMISSIONS ........................................................................................................ 41  4.2   ENERGY AND FUEL EFFICIENCY ....................................................................................... 42  4.3   KEY FINDINGS AND RECOMMENDATIONS ........................................................................ 44  

4.3.1   Key findings and recommendations for stakeholders ................................................ 45  4.3.2   Key recommendations ............................................................................................... 45  

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LIST OF TABLES Table 2.1 Bus acronym and description .......................................................................................................... 6  Table 2.2 Drive cycle characteristics for HB2-S in Rio de Janeiro ............................................................... 11  Table 2.3 Drive cycle characteristics for Sao Paulo ...................................................................................... 11  Table 2.4 Drive cycle characteristics for Bogota .......................................................................................... 12  Table 2.5 Drive cycle characteristics for Santiago ........................................................................................ 13  Table 3.1 Bus acronym and description ........................................................................................................ 16  Table 3.2 Raw results of emissions and fuel consumption, Rio de Janeiro .................................................. 16  Table 3.3 Raw results of emissions and fuel consumption, Sao Paulo ......................................................... 17  Table 3.4 Raw results of emissions and fuel consumption, Bogota .............................................................. 19  Table 3.5 Raw results of emissions and fuel consumption, Santiago ........................................................... 20  Table 3.6 Normalized results of emissions and fuel consumption, Rio de Janeiro ....................................... 35  Table 3.7 Normalized results of emissions and fuel consumption, Sao Paulo .............................................. 36  Table 3.8 Normalized results of emissions and fuel consumption, Bogota .................................................. 37  Table 3.9 Normalized results of emissions and fuel consumption, Santiago ................................................ 39  

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LIST OF FIGURES Figure 1.1 Testing methodology for exhaust emissions and fuel consumption .............................................. 3  Figure 2.1 Fuel consumption test results in Rio de Janeiro ............................................................................ 7  Figure 2.2 Fuel consumption test results in Sao Paulo .................................................................................... 8  Figure 2.3 Fuel consumption test results in Bogota ........................................................................................ 9  Figure 2.4 Fuel consumption test results in Santiago .................................................................................... 10  Figure 2.5 Drive Cycle for HB1-P in Rio de Janeiro .................................................................................... 11  Figure 2.6 Common Drive Cycle for Sao Paulo ............................................................................................ 12  Figure 2.7 Common Drive Cycle for Bogota ................................................................................................ 13  Figure 2.8 Common Drive Cycle for Santiago .............................................................................................. 14  Figure 3.1 Raw results normalized in comparison with DB1-R in Rio de Janeiro ....................................... 17  Figure 3.2 Raw results normalized in terms of DB-R in Sao Paulo .............................................................. 19  Figure 3.3 Raw results normalized in terms of DB1-R in Bogota ................................................................ 20  Figure 3.4 Raw results normalized in terms of DB1-R in Santiago .............................................................. 21  Figure 3.5. CO2 per VSP-Bin Rio de Janeiro ................................................................................................ 23  Figure 3.6. NOx per VSP-Bin Rio de Janeiro ............................................................................................... 24  Figure 3.7. PM1.5 per VSP-Bin Rio de Janeiro ............................................................................................ 25  Figure 3.8. CO2 per VSP-Bin Sao Paulo ....................................................................................................... 26  Figure 3.9. NOx per VSP-Bin Sao Paulo ...................................................................................................... 27  Figure 3.10. PM1.5 per VSP-Bin Sao Paulo ................................................................................................. 28  Figure 3.11. CO2 per VSP-Bin Bogotá .......................................................................................................... 29  Figure 3.12. NOx per VSP-Bin Bogotá ......................................................................................................... 30  Figure 3.13. PM1.5 per VSP-Bin Bogotá ...................................................................................................... 31  Figure 3.14. CO2 per VSP-Bin Santiago ....................................................................................................... 32  Figure 3.15. NOx per VSP-Bin Santiago ...................................................................................................... 33  Figure 3.16. PM1.5 per VSP-Bin Santiago ................................................................................................... 34  Figure 3.17 Normalized results normalized in terms of DB-R in Rio de Janeiro ......................................... 36  Figure 3.18 Normalized results normalized in terms of DB-R in Sao Paulo ................................................ 37  Figure 3.19 Normalized results normalized in terms of DB-R in Bogota ..................................................... 39  Figure 3.20 Normalized results normalized in terms of DB-R in Santiago .................................................. 40  Figure 4.1 Emissions reductions for carbon dioxide and criteria pollutants ................................................. 42  Figure 4.2Fuel and energy consumption results ............................................................................................ 43  Figure 4.3 Fuel and energy consumption results per passenger .................................................................... 44  

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LIST OF ACRONYMS CCI Clinton Climate Initiative HEBTP Hybrid-Electric Buses Test Program GHG Green House Gas BRT Bus Rapid Transit HB Hybrid Bus DB Diesel Bus HB1-P Hybrid Bus 1 - Parallel configuration, running on conventional diesel and electricity HB1-S Hybrid Bus 1 - Serial configuration, running on conventional diesel and electricity EB1 Electric Bus 1 running on electricity only DB1-R Diesel Bus 1 – Reference, running on conventional diesel DB2-F Diesel Bus 2 – Filter, running on conventional diesel and fitted with DPF DB2-N Diesel Bus 2 – New, running on conventional diesel, new technology DB2-A Diesel Bus 2 – Articulated, running on conventional diesel, 18 mt long VSP Vehicle Specific Power SCR Selective Catalytic Reduction for NOx control FE Fuel Efficiency in kilometers per liter FC Fuel Consumption in liters per 100 kilometers GPS Global Positioning System FE fm Fuel Efficiency flowmeter DPF Diesel Particulate Filter DOC Diesel Oxidation Catalyst LATAM Latin America SOC State of Charge of the battery pack

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Sao  Paulo  Report  for  C40-­‐CCI-­‐IDB  Hybrid  Electric  Bus  Test  Program  in  Latin  America  

International  Sustainable  Systems  Research  Center       1  

1 INTRODUCTION

1.1 General Background The Hybrid and Electric Bus Test Program (the “Program”) was conceived by C40-CCI, and has been actively supported by the IDB with a financial contribution of $1.49 million. C40-CCI as the implementing agency was responsible for gathering contributions from multiple stakeholders, and especially those involved in the testing of hybrid and electric buses and, for comparison purposes, conventional diesel vehicles. The Program aims to help cities to make sound decisions regarding test bus technology performance in city-specific driving conditions and duty cycles, with special attention to bus operating costs and to local emissions of air pollutants and emissions of GHG. The Program establishes the case for investment in hybrid and electric buses by bus technology companies, cities, and local transport operators; compiles and shares results within a network of participants, interested parties and cities in Latin American countries; and is designed ultimately to lead to the deployment of up to 9,000 hybrid and electric buses across Latin American cities in the period up to 2018, resulting in a steady-state reduction of 475,000 tons of carbon dioxide (CO2) emissions annually. Local governments, bus suppliers and operators in Bogota, Sao Paulo, Rio de Janeiro and Santiago implemented the Program. The results of testing and economic analysis have contributed to building a database that has been shared among cities and is helping to speed up decisions related to the incorporation of efficient, low emissions bus technologies. Reduction of GHG emissions will be demonstrated by verifying that performance of various hybrid bus technologies is superior to conventional public transport vehicles. Performance will be evaluated in different geographical altitudes and driving cycles. Test results will enable manufacturers to make appropriate adjustments to bus design or operation while guiding cities in the purchase of new or replacement fleets for existing, new Bus Rapid Transit (BRT) or conventional systems.

1.2 Organization of this Report

1.3 General Methodology Vehicle emissions determination is a complex science; the most important challenge is to obtain representative results of a given technology under real operating conditions. In addition, it is particularly challenging to measure direct exhaust emissions from heavy-

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International  Sustainable  Systems  Research  Center     2  

duty vehicles (trucks or buses), mainly because laboratory equipment required to test these vehicles is almost inexistent in Latin America and most developing countries. A new methodology has been internationally developed to overcome these challenges; this methodology is called On Road Testing and to put it in practice Portable Emissions Measurement Systems (PEMS) are required. On the research performed on this Program, On Road Testing and PEMS have been applied to measure 17 buses in 4 cities of South America (Bogota, Sao Paulo, Santiago and Rio de Janeiro). Basically, the methodology used in this Program is dealing with the following challenges:

• Testing buses with different technologies, in 4 Latin American cities using a common and robust methodology

• Measure exhaust emissions and energy performance from real buses performing under real operating conditions

• Being able to report comparative results between technologies and cities In order to tackle the above challenges, ISSRC has performed a rigorous protocol in each city participating in the Program, applying its IVE1 methodology for measuring tailpipe emissions, driving cycles and energy use, and combining all these results through the Vehicle Specific Power (VSP) binning methodology. Testing protocol comprises two phases, as shown in Figure 1.1. Phase 1 uses PEMS equipment for measuring direct raw emissions from the exhaust tailpipe of each bus burning diesel fuel (diesel and hybrid technologies). Phase 2 measures energy use and driving characteristics while buses are running under representative operating conditions in each city (diesel, hybrid and electric technologies). After both phases have been performed, following a protocol of 10 repetitions for Phase 1 and 50 repetitions for Phase 2, all results follow a normalization procedure in order to compare results. On one hand, exhaust emissions are statistically binned according to the energy required to move the bus, following the vehicle specific power delivered and the amount of pollutants emitted per second for each bus. This procedure is repeated for CO, HC, NOx, PM1.5 and CO2 and provides a matrix of VSP Emissions. On the other hand, driving cycles from all diesel-burning buses are combined into a single cycle per city. Driving dynamics of this single cycle are also binned according to vehicle’s specific power, producing a set of driving conditions linked to levels of energy required to operate the bus along the designated route on each city. It is important to note that Phase 1 and Phase 2 do not necessarily share the same route. This procedure generates a VSP Driving matrix, which is associated to an energy efficiency measured under the same conditions.

1  International  Vehicle  Emissions  Model,  IVE,  available  at  www.issrc.org/ive  

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International  Sustainable  Systems  Research  Center   3  

Crossing both matrices, VSP-Emissions and VSP-Driving, produces a set of normalized emissions where all pollutants are estimated assuming the same driving characteristics. These emissions results are compared with fuel consumption and a validation process through carbon balance takes place closing the circuit. Using the VSP Binning Methodology both emissions and driving cycle can be classified under different energy demand situations. The advantage of this methodology relays on its versatility, combining VSP Emissions and VSP Driving allows evaluations of emissions under different routes for these buses or technologies.

Figure 1.1 Testing methodology for exhaust emissions and fuel consumption

Phase 1 has been designed to obtain emissions under all possible energy demand situations of a bus, defined as Emissions divided by Vehicle Specific Power (VSP Bin). This phase allows the evaluation of different Driving Pattern or Driving Cycles for the bus on the city, even future cycles developed by the city.

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International  Sustainable  Systems  Research  Center     4  

Phase 2 has been designed to measure energy efficiency and to determine driving cycles under real world situations, basically under an existing bus route. In order to obtain representative results each bus ran this route for at least 25 hours. Energy consumption was recorded using an external tank with a fuel flowmeter for diesel and with electronic equipment for hybrid and electric buses. In addition, each bus was equipped with a high resolution GPS which recorded bus position each second. This data frequency allows for fine energy demand analysis making possible the precise calculation of VSP binning.

1.4 About Hybrid & Electric Bus Technologies Hybrid and electric bus technologies are recognized as low carbon technologies. Hybrid buses combine a conventional internal combustion engine propulsion system with an electric propulsion system. These types of buses normally use a diesel-electric power-train and are also described as hybrid diesel-electric buses. The electric power-train is intended to achieve better fuel economy than in a conventional vehicle. Modern hybrid diesel-electric buses make use of efficiency-improving technologies such as regenerative braking, which converts the vehicle's kinetic energy into electric energy to charge the battery rather than it being dissipated as heat energy whenever the vehicle slows down. In general, hybrid electric vehicles can be classified according to how the power is supplied to the drive-train: in parallel or in series. In parallel hybrids, both the internal combustion engine and the electric motor are connected to the mechanical transmission and can simultaneously transmit power to drive the wheels, usually through a conventional transmission. In series hybrids, only the electric motor drives the drive-train, and the internal combustion engine works as a generator to power the electric motor or to recharge the batteries. Series hybrids usually have smaller combustion engines and larger battery pack compared to parallel hybrids. Parallel hybrids have smaller engines compared to the equivalent diesel bus. Hybrid buses do not require incremental investments in infrastructure. The hybrid system consumes less fuel and correspondingly reduces CO2, nitrogen oxides, and particulate matter emissions. Electric buses are powered by electricity and propelled by electric motors. They can be connected by wires or run on batteries that need to be plugged into an electricity source and recharged over several hours. Battery-based vehicles run on chemical energy stored in rechargeable battery packs and do not have an internal combustion engine. These battery electric vehicles (BEV) or electric buses are dependent on the battery being plugged in at a charging station. Battery electric buses are propelled by motor controllers and electric motors instead of internal combustion engines. The motor controller regulates the power to the motor, which can be either a central electrical motor or, more recently, an in-wheel motor system. The wheel hub motor is an electric motor that is incorporated into the wheel hub which it drives directly, conferring additional savings by

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International  Sustainable  Systems  Research  Center   5  

eliminating the need for a transmission, differential, and related mechanical parts. This reduces both the overall weight of the bus and energy losses due to friction. Tail pipe emissions generated by an electric bus can be close to zero if the electricity used to charge it comes from low-carbon generating sources such as hydroelectricity. Vehicle GHG savings depend also on how the electricity is generated. A fleet of electric buses requires charging stations in bus terminals, a combination between quick-charging and slow-overnight charging schemes or multiple recharging per day at bus stops, which requires changes to the street infrastructure. The Program shows the better performance of hybrid and electric buses compared to conventional diesel buses in relation to exhaust emissions and energy efficiency. In Latin American countries the adoption of new low carbon technologies is subject to various policy scenarios regarding regulation and tax systems. For example, current subsidies for diesel tip the balance towards investing in conventional diesel technology, and import barriers in the form of duties favor continuation of local established production of diesel buses. Life-cycle costs are also a factor in long-term evaluations of operating costs. In analyzing different possible market scenarios, provision of technical assistance, and a secondary market at the end of the life cycle can be important. Although the economic life cycle of a hybrid or electric bus is shorter than that of a diesel bus, over a 10-year period the case should not be argued on economic grounds only. The bottom line in economic terms is a higher initial cost and a competitive operating cost, plus very low maintenance costs for electric buses. Their greatest advantages are the environmental, health, and social benefits of this technology. Decisions to adopt low carbon technologies could drive policy and market conditions and make these technologies more competitive and more convenient than traditional ones.

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International  Sustainable  Systems  Research  Center     6  

2 Energy Performance and Driving Cycles

2.1 Fuel and Energy consumption The Program tested fuel consumption for diesel-only and hybrid diesel-electric buses, as well as energy performance for full electric buses. Results varied by city, as showed in Figures 5 to 8, but in all cases energy efficiency of parallel-hybrid and full-electric buses was better than traditional diesel buses. Two electric vehicles, seven hybrid technologies and six diesel-only buses were tested in the four cities participating in the Program. In terms of fuel consumption, parallel-hybrid technologies reported an average of 31% reduction in fuel use compared to diesel buses. For electric buses an equivalent amount of diesel fuel was determined (eq-fuel), based on local electricity costs per kWh and diesel value per liter. Under these assumptions, electric technologies showed 76% eq-fuel consumption reduction comparing between buses, as an average for Santiago and Bogota. This reduction gets down to 59% if eq-fuel consumption per passenger is calculated, due to a lower carrying capacity when comparing electric and diesel-only vehicles. 2 Fuel consumption results per city are described below, where diesel buses are denominated as DB1 and DB2, hybrid buses are denominated as HB1 and HB2 and electric buses are EB1-1 and EB1-2. As well as before, it is important to note that these acronyms are not necessarily referred to the same buses or technologies when moving from city to city. The analysis included comparisons of fuel consumption by bus (FC) and by passenger (FC/pax), using the corresponding reference DB1 in each city. Different bus technologies were tested for fuel and energy consumption measurement and their designation for the analysis below are the following:

Table 2.1 Bus acronym and description

ID BUS DESCRIPTION

DB1-R Diesel Bus Reference tested in each city

DB2-F Diesel Bus with particulate Filter tested only in Santiago

DB2-A Diesel Bus Articulated tested only in Sao Paulo

HB1-P HB2-P Hybrid Bus Parallel configurations

TB1-S Hybrid Bus Serial configuration

EB1-C Electric Bus - equivalent fuel consumption based in energy Costs

EB1-E Electric Bus - equivalent fuel consumption based in Energy content

2  Diesel  buses  have  a  greater  passenger  capacity  given  their  comparatively  lighter  weight.  Hybrid  buses  have  20-­‐30%  less  capacity  than  diesel  buses  and  electric  buses  40-­‐50%  less.  

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International  Sustainable  Systems  Research  Center   7  

Data for consumption for electric buses was compared to the base line per monetary value and per unit of energy used. EB1-C estimates equivalent FC converting kWh into liters of fuel using local prices for each type of energy source, thus including local subsidies and/or taxes in the analysis. EB1-E estimates FC converting kWh and liters into kcal of energy, thus avoiding distortions or fluctuations from local energy market prices.

2.1.1 Rio de Janeiro Four buses were tested in Rio de Janeiro: a diesel reference bus (DB1), a newer Euro 4 diesel bus (DB2), a parallel-hybrid bus (HB1) and a serial-hybrid bus (HB2). Similarly to the case for emissions, strong differences between the two hybrid technologies were found for fuel use. The serial-hybrid (HB2) has considerably higher FC than DB1, while the parallel vehicle (HB1) was consistently lower. Hybrid Bus 1 (HB1) reported the best fuel performance, with 32% less FC than DB1. Hybrid Bus 2 reported the worst fuel consumption, with 3% higher FC than DB1.

Figure 2.1 Fuel consumption test results in Rio de Janeiro

2.1.2 Sao Paulo Figure 2.2 shows results for Sao Paulo, where four buses were tested: a 12-meter diesel reference bus (DB1), an 18-meter diesel articulated bus (DB2), a 12-meter parallel-hybrid bus (HB1) and a 12-meter serial-hybrid bus (HB2). In general hybrid technologies had less fuel consumption than diesel standard technology. There was 42% reduction in fuel consumption (FC) for HB1 and 22% for HB2. This reduction goes up to 47% for HB1 when fuel consumption per passenger (FC/pax) is estimated and gets down to 14% for

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Santiago  Report  for  C40-­‐CCI-­‐IDB  Hybrid  Electric  Bus  Test  Program  in  Latin  America  

International  Sustainable  Systems  Research  Center     8  

HB2, due to its lower capacity. DB2 shows 16% higher FC than DB1, but due to its larger capacity FC/pax is 19% lower (comparable to HB2).

Figure 2.2 Fuel consumption test results in Sao Paulo

2.1.3 Bogota Figure 2.3 shows two hybrid-parallel technologies and one full-electric bus compared with one reference diesel bus in Bogota. Hybrid and electric technologies had less fuel consumption than diesel standard technology, under comparable conditions. There was a 33% reduction of fuel consumption (FC) as an average for HB1 and HB2 technologies. This reduction goes down to 31% for HB1 when fuel consumption per passenger (FC/pax) is estimated and gets up to 43% for HB2, due to its higher capacity. There was one electric bus in Bogota, and its equivalent fuel consumption has been estimated using the two approaches explained above. For EB1-1, equivalent fuel consumption per bus was 72% lower for the electric bus in Bogota, compared with DB1, or 52% lower for equivalent FC/pax. For EB1-2 the same above savings were 81% and 71% respectively.3

3  Costs  of  energy  in  Bogota  were,  at  the  time  of  analysis,  0.17  U$/kW  and  1.21  U$/liter  of  fuel  

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Santiago  Report  for  C40-­‐CCI-­‐IDB  Hybrid  Electric  Bus  Test  Program  in  Latin  America  

International  Sustainable  Systems  Research  Center   9  

Figure 2.3 Fuel consumption test results in Bogota

2.1.4 Santiago Testing in Santiago comprised four buses for energy performance analysis. A diesel bus used as reference (DB1), a second diesel bus fitted with particle filter and oxidation catalyst (DB2), a parallel-hybrid bus (HB1) and a full-electric bus (EB1). There was 40% reduction of fuel consumption (FC) for HB1. This reduction goes down to 25% for HB1 when fuel consumption per passenger (FC/pax) is estimated, due to its lower capacity. There was one electric bus in Santiago and, as well as in Bogota, its equivalent fuel consumption has been estimated using two approaches. EB1-1 estimates equivalent FC converting kWh into liters of fuel using local prices for each type of energy source. EB1-2 estimates FC converting kWh and liters into kcal of energy. For EB1-1, equivalent fuel consumption per bus was 79% lower, compared with DB1, or 60% lower for equivalent FC/pax. For EB1-2 the same above savings were 73% and 50% respectively. Electricity costs per kWh are lower in Santiago than in Bogota, while diesel cost per liter is similar in both cities. This distortion makes electricity more attractive in Santiago.4

4  Costs  of  energy  in  Santiago  were,  at  the  time  of  analysis,  0.086  U$/kW  and  1.155  U$/liter  of  fuel  

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Santiago  Report  for  C40-­‐CCI-­‐IDB  Hybrid  Electric  Bus  Test  Program  in  Latin  America  

International  Sustainable  Systems  Research  Center     10  

Figure 2.4 Fuel consumption test results in Santiago

2.2 Driving Cycles According to the methodology, each city participating in the Program selected one or two bus routes for conducting this testing. Each bus ran along the designated route during 10 hours for Phase 1 and 25 hours for Phase 2. Phase 1 provided emissions in grams per kilometer and also emissions per VSP bins. Phase 2 provided energy consumption and also driving dynamics recorded along the route. Several drive cycles have been created using GPS data collected in Phase 2. Each driving cycle has two sections with the same duration, the first one corresponding to low speed conditions and the second one representing high speed operation. There is one cycle for each bus participating in the program and, even the buses used the same route, there are differences in their driving behavior due to several factors such as vehicle technology, driver habits, variations in traffic conditions, and weather conditions. In order to generate emissions results that are comparable, a common driving cycle has been produced combining cycles from all buses using diesel fuel (thus conventional diesel and hybrid buses). A VSP-Driving matrix is generated from this cycle, applying VSP binning methodology. Combining VSP-Emissions and VSP-Driving matrices, a set of Normalized Emissions is calculated, where all buses share the same operating conditions. Next, a summary of driving cycles for each bus and the common driving cycle used to normalize emissions is shown.

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Santiago  Report  for  C40-­‐CCI-­‐IDB  Hybrid  Electric  Bus  Test  Program  in  Latin  America  

International  Sustainable  Systems  Research  Center   11  

2.2.1 Rio de Janeiro Four buses were tested in Rio de Janeiro: a reference diesel (DB1-R), a new diesel model with modern technology (DB2-N), a parallel hybrid bus (HB1-P) and a serial hybrid bus (HB2-S).

Table 2.2 Drive cycle characteristics for HB2-S in Rio de Janeiro

Variable Low Speed High Speed

Cycle length [s] 600 600 Idle [%] 52 14 Operation [%] 48 86 Average Speed [km/h] 3.39 22.68 Average Acceleration [m/s2] 0.452 0.49 Average Deceleration [m/s2] -0.34 -0.543 Maximum Speed [km/h] 25.308 54.396 Maximum Acceleration [m/s2] 2.33 5.03 Maximum Deceleration [m/s2] -2.37 -3.04

Figure 2.5 Drive Cycle for HB1-P in Rio de Janeiro

2.2.2 Sao Paulo Four buses were tested in Sao Paulo: a reference diesel (DB1-R), a parallel hybrid bus (HB1-P), a serial hybrid bus (HB2-S) and a conventional trolley bus (TB1). Combining driving characteristics from the above buses (one reference diesel and two hybrid vehicles) a common driving cycle has been created, which is described below.

Table 2.3 Drive cycle characteristics for Sao Paulo

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Variable Low Speed High Speed

Cycle length [s] 240 240 Idle [%] 46.25 15.42 Operation [%] 53.75 84.58 Average Speed [km/h] 7.037 20.866 Average Acceleration [m/s2] 0.585 0.402 Average Deceleration [m/s2] -0.717 -0.479 Maximum Speed [km/h] 29.376 40.536 Maximum Acceleration [m/s2] 1.63 3.97 Maximum Deceleration [m/s2] -1.86 -4.19

Figure 2.6 Common Drive Cycle for Sao Paulo

2.2.3 Bogota Four buses were tested in Bogota: a reference diesel (DB1-R), two parallel hybrid buses (HB1-P and HB2-P) and a full electric bus (EB1). Combining driving characteristics from the above buses (one reference diesel and two hybrid vehicles) a common driving cycle has been created, which is described below.

Table 2.4 Drive cycle characteristics for Bogota

Variable Low Speed High Speed

Cycle length [s] 240 240 Idle [%] 31.25 15.417 Operation [%] 68.75 84.583 Average Speed [km/h] 15.580 25.937 Average Acceleration [m/s2] 0.323 0.387

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Average Deceleration [m/s2] -0.483 -0.586 Maximum Speed [km/h] 33.627 47.524 Maximum Acceleration [m/s2] 0.93 2.28 Maximum Deceleration [m/s2] -1.7 -1.75

Figure 2.7 Common Drive Cycle for Bogota

2.2.4 Santiago Four buses were tested in Santiago: a reference diesel (DB1-R), a diesel model fitted with diesel particle filter (DB2-F), a parallel hybrid bus (HB1-P) and a full electric bus (EB1). Combining driving characteristics from the above buses (two diesel and one hybrid vehicle) a common driving cycle has been created, which is described below.

Table 2.5 Drive cycle characteristics for Santiago

Variable Low Speed High Speed

Cycle length [s] 240 240 Idle [%] 44.583 18.333 Operation [%] 55.417 81.667 Average Speed [km/h] 7.489 21.860 Average Acceleration [m/s2] 0.617 0.572 Average Deceleration [m/s2] -0.649 -0.849 Maximum Speed [km/h] 35.463 48.676 Maximum Acceleration [m/s2] 1.36 1.2 Maximum Deceleration [m/s2] -2.02 -2.43

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Figure 2.8 Common Drive Cycle for Santiago

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3 Exhaust Emissions and Energy Consumption This chapter describes exhaust emissions and energy consumption results, based on the methodology used in this project. As a first step for measuring emissions, each bus was tested for around 10 hours with Portable Emissions Measurement Systems (PEMS). This stage is defined as Phase 1 and two important results were obtained from here: 1) Raw Average Emissions (Section 3.1) and 2) Emissions by Energy Demand or Vehicle Specific Power (Section 3.2). Raw Average Emissions correspond to a direct result of exhaust emissions in grams per kilometre, but since the bus is under certain operational restrictions due to the equipment installed in the interior, these emissions are not totally representative of the same bus in normal operations. To overcome this issue, emissions are recorded at 1Hz frequency, allowing the correlation of driving behaviour with instant emissions (second by second). This frequency for measuring and collecting data allows the calculation of emissions by vehicle energy demand. Thus, emissions in terms of Energy Demand or by Vehicle Specific Power (VSP) are obtained in grams per second according to different energy bins. With this binning distribution analysis, emissions can be matched to specific situations such as idling, braking or accelerating. In addition, this methodology allows estimating emissions for any driving pattern of the city. Thus, emissions can be modelled in different routes from their representative driving patterns. Simultaneously, in Phase 2 each bus was tested in real traffic conditions, for 25 hours for one week. This Phase has two main products: 1) Fuel Efficiency and 2) Driving Cycle Development. Both results are obtained under real world conditions on a representative route defined by a local team in each city. Adding all driving results for all buses in each city, a common cycle was developed. This cycle has the distinction of representing a normalized driving behaviour. Each overall cycle included data recorded from 75 to 100 hours (270,000 to 360,000 seconds) of real conditions on a representative route. Finally, emissions by VSP and the common cycle of each city are processed together to obtain Normalized Emissions (Section 3.3). These emissions are comparable considering that each bus emissions are evaluated under the same driving pattern or driving behaviour.

3.1 Overall raw emissions results The following section describes exhaust tailpipe emissions and fuel consumption performed by each bus tested in Rio de Janeiro, Sao Paulo, Bogota and Santiago. These results are directly taken from Phase 1 and are considered raw results.

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Different bus technologies were tested for emissions measurement and their designation for the analysis below are the following:

Table 3.1 Bus acronym and description

ID BUS DESCRIPTION

DB1-R Diesel Bus Reference tested in each city

DB2-F Diesel Bus with particulate Filter tested only in Santiago

DB2-A Diesel Bus Articulated tested only in Sao Paulo

HB1-P HB2-P Hybrid Bus Parallel configuration

HB2-S Hybrid Bus Serial configuration

Regarding fuel consumption (FC), raw results are included in accordance with the testing phase where they were obtained. Fuel consumption measurements under emissions testing methodology (Phase 1) are designed as FC Ph1.

3.1.1 Rio de Janeiro The first city were tests were performed was Rio de Janeiro. Table 3.2 shows raw results performed by buses in Rio de Janeiro for emissions and fuel consumption.

Table 3.2 Raw results of emissions and fuel consumption, Rio de Janeiro

ID BUS THC (g/km)

CO (g/km)

NOx (g/km)

CO2 (g/km)

PM1.5 (g/km)

FC Ph1 [L/100km]

DB1-R 0.12 5.46 10.07 1,073.4 0.10 39.37 HB1-P 0.04 1.06 5.19 891.6 0.03 32.79 HB2-S - 6.39 12.52 1,776.2 0.22 58.82

In general, HB1-P performed with lower emissions rates (g/km) than DB1-R an average emission reduction was 58%, considering all pollutants measured. The greatest emission reduction result was for CO with 81%. Regarding NOx and PM1.5 in HB1-P, emission rates reached 5.19 (g/km) and 0.03 (g/km), which is equivalent to a reduction of 48% for NOx and 74% for PM1.5. CO2 emissions were 1,073 (g/km) and 891.6 (g/km) for DB1-R and HB1-P, respectively, and equivalent HB1-P emission reduction was 17% with respect to DB1-R. Results for

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fuel consumption (L/100km) in HB1-P running under Phase 1 methodology were 17% lower than DB-R. In case of HB2-S tested in Rio de Janeiro, in general, it performed with higher emissions rates (g/km) than DB1-R and average emission increase was 57%, considering all pollutants measured. Figure 3.1 shows the difference between diesel reference bus (DB1-R) and hybrid buses tested in Rio de Janeiro, where raw results have been compared in terms of DB1-R emissions and fuel consumption results (DB1-R is 1).

Figure 3.1 Raw results normalized in comparison with DB1-R in Rio de Janeiro

3.1.2 Sao Paulo Following Rio de Janeiro, the second city where tests were performed was Sao Paulo. In addition to the buses tested during the first campaign, a serial hybrid bus was measured during the second campaign. Table 3.3 shows raw results performed by all buses tested in Sao Paulo for emissions and fuel consumption.

Table 3.3 Raw results of emissions and fuel consumption, Sao Paulo

ID BUS THC (g/km)

CO (g/km)

NOx (g/km)

CO2 (g/km)

PM1.5 (g/km)

FC Ph1 [L/100km]

DB1-R 0.19 8.83 13.52 1,442.1 0.32 53.45 DB2-A 5.85 13.76 1,655.8 0.18 61.21 HB1-P 0.08 1.02 7.38 995.3 0.10 35.88 HB2-S 1.86 7.19 1,265.2 47.44

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Hybrid buses, both parallel and serial configuration, performed with lower emissions rates (g/km) than DB1-R. Average emission reductions were, 58% and 46% for HB1-P and HB2-S5, respectively. The greatest emission reduction results were in CO with 88% for HB1-P and 79% for HB-S. Regarding NOx in hybrid technology, HB1-P and HB2-S emissions rates reached 7.38 (g/km) and 7.19 (g/km), which is equivalent to 45% and 47% emission reduction with respect to DB1-R bus, respectively. In case of HB1-P, emissions reduction for PM1.5 was 70% lower than DB1-R bus and absolute values were 0.10 (g/km) for HB1-P and 0.32 (g/km) for DB1-R. CO2 emissions were 1,442 (g/km), 995.3 (g/km) and 1,265 (g/km) for DB1-R, HB1-P and HB2-S, respectively, and equivalent HB1-P and HB2-S emission reductions were 31% and 12% with respect to DB1-R. Results for fuel consumption (L/100km) in HB1-P and HB2-S running under Phase 1 methodology were 33% and 11% lower than DB1-R bus, respectively. An articulated diesel bus DB2-A was tested in Sao Paulo which performed with higher NOx and CO2 emissions rates than DB1-R with 2% and 15% of increment, respectively. On the other hand, DB2-A results for CO and PM1.5 emissions were lower than DB1-R bus with 34% and 44% reductions, respectively. Figure 3.2 shows differences between diesel reference bus (DB1-R), hybrid buses and the articulated diesel bus (DB2-A) tested in Sao Paulo, where raw results have been normalized in terms of DB1-R emissions and fuel consumption results.

5  There  are  no  THC  and  PM1.5  measurements  for  HB1-­‐S  in  Sao  Paulo  

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Figure 3.2 Raw results normalized in terms of DB-R in Sao Paulo

3.1.3 Bogota The third campaign of the Program was performed in Bogotá, Colombia. Four buses were tested, a reference diesel bus, 2 hybrid buses and 1 full electric bus. Only results for the buses with an internal combustion engine are analysed in this subsection. Table 3.4 shows raw results performed by buses in Bogota for emissions and fuel consumption.

Table 3.4 Raw results of emissions and fuel consumption, Bogota

ID BUS THC (g/km)

CO (g/km)

NOx (g/km)

CO2 (g/km)

PM1.5 (g/km)

FC Ph1 [L/100km]

DB1-R 0.53 6.40 12.19 1,011.0 0.066 37.66 HB1-P 0.03 2.64 1.70 796.6 0.021 29.94 HB2-P 0.03 3.95 6.07 890.7 0.019 33.58

In general, both HB-P buses performed with lower emissions rates (g/km) than DB1-R and average emission reduction was 59%, considering all pollutants measured in both hybrid buses: HB1-P and HB2-P. The greatest emission reduction results were in THC with 94% for HB1-P and 95% for HB2-P. Regarding NOx in hybrid technology, HB1-P and HB2-P emissions rates reached 1.70 (g/km) and 6.07 (g/km), which is equivalent to 86% and 50% emission reduction with respect to DB-R, respectively. Emissions reductions for PM1.5 were 68% (HB1-P) and 71% (HB2-P) in comparison with DB1-R and absolute values were 0.021 (g/km) for HB1-P, 0.019 (g/km) for HB2-P and 0.066 (g/km) for DB1-R.

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CO2 emissions were 1,011 (g/km), 796.6 (g/km) and 890.7 (g/km) for DB1-R, HB1-P and HB2-P, respectively, and equivalent HB1-P bus and HB2-P emission reductions were 21% and 12% with respect to DB-R bus. Results for fuel consumption (L/100km) in HB1-P and HB2-P running under Phase 1 methodology were 20% and 11% lower than DB1-R, respectively. Figure 3.3 shows difference between diesel reference bus (DB1-R) and hybrid buses tested in Bogota, where raw results have been normalized in terms of DB1-R emissions and fuel consumption results.

Figure 3.3 Raw results normalized in terms of DB1-R in Bogota

3.1.4 Santiago The last city where tests were performed was Santiago, Chile. In Santiago, 4 buses were tested. Once again only the internal combustion engines buses are analysed in this sub section. In Santiago, a diesel bus equipped with a particle filter was tested and compared against the hybrid bus, Table 3.5 shows raw results performed by bus in Santiago for emissions and fuel consumption.

Table 3.5 Raw results of emissions and fuel consumption, Santiago

ID BUS THC (g/km)

CO (g/km)

NOx (g/km)

CO2 (g/km)

PM1.5 (g/km)

FC Ph1 [L/100km]

DB1-R 0.10 13.32 12.76 1,030.6 0.029 38.92 DB2-F 0.02 1.84 15.44 956.9 0.001 36.00 HB1-P 0.03 0.37 2.55 667.4 0.007 25.21

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In general, HB1-P produced lower emissions rates (g/km) than DB1-R and average emission reduction was 72%, considering all pollutants measured. The greatest emission reduction result was in CO with 97%. Regarding NOx and PM1.5, HB1-P, emissions rates reached 2.55 (g/km) and 0.007 (g/km), which is equivalent to 80% and 76% emission reduction with respect to the DB1-R bus, respectively. CO2 emissions were 1,030 (g/km) and 667.4 (g/km) for DB1-R and HB1-P, respectively, and the equivalent HB1-P bus emission reduction was 35% with respect to DB1-R. Results for fuel consumption (L/100km) in HB1-P running under Phase 1 methodology were 35% lower than DB-R bus. DB2-F, a diesel bus equipped with a Diesel Particle Filter was tested in Santiago, which operates with lower emissions rates than DB1-R bus in all pollutants with exception of NOx. PM1.5 emission reduction was 97% and reached 0.001 (g/km). However, NOx emissions increased 21% and reached 15.44 (g/km). Regarding CO2 emissions, DB2-F reduced 7% with respect to DB1-R, equivalent to 956.9 (g/km). Figure 3.1 shows differences between diesel reference bus (DB1-R) and hybrid buses tested in Santiago, where raw results have been normalized in terms of DB1-R emissions and fuel consumption results.

Figure 3.4 Raw results normalized in terms of DB1-R in Santiago

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3.2 Emissions by Energy Demand Situations per City As previously mentioned in this report, important sets of results from this study are emissions per unit energy demand. These types of results are only possible using high frequency reading equipment on a real world testing procedure. The importance of this approach is based on the versatility to use it in future applications, allowing comparisons of technology behavior under different energy demand situations and the possibility to give recommendations on how to optimize engines or even drivers during bus operation. Emissions by energy demand or by Vehicle Specific Power (VSP) are widely used in the USEPA to make comparisons between technologies. On the appendix of each city report VSP methodology is explained in detail and should be reviewed to better understand the following results. In this case the VSP methodology used is according to the IVE model methodology (www.issrc.org/ive). In the following subsections, emissions by VSP per city are compared and analyzed.

3.2.1 Rio de Janeiro In Rio de Janeiro, the first field campaign, four buses were tested: a diesel reference bus (DB1-R), a new diesel euro 3 bus (not included in the analysis because it lacks the testing minimum time) and two hybrid buses, a parallel hybrid (HB1-P) and a serial hybrid (HB2-S). On the following graphs, emissions results by Vehicle Specific Power Bins (9 to 14) for 3 buses are shown. Each Bin represents a comparable energy demand situation. Bins 9 to 10 represent decelerating conditions, Bin 11 near idling conditions and Bin 12 to 14 accelerating conditions. On the first graph, CO2 emissions are compared for DB1-R and HB1-P. CO2 emissions are comparable for almost every VSP Bin, a noticeable difference appears in Bin 12 where HB1-P shows a 13% reduction against DB1-R. Bin 12 is the first energy situation after idling, and normally a high percentage of the driving is made under this situation, this difference explains a possible overall CO2 emissions reduction. Since HB2-S is a serial hybrid6, it shows a totally different emissions pattern. Basically, under any energy situation emissions stay constant. For VSP Bins 9 to 11 emissions are more than double DB1-R emissions. This result explains high overall CO2 for this bus, considering that most of the driving is made under VSP Bin 11.

6  In  serial  configurations  the  internal  combustion  engine  is  used  at  constant  rpm  as  a  generator  to  charge  the  batteries  

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Figure 3.5. CO2 per VSP-Bin Rio de Janeiro

For NOX emissions, VSP analysis shows the difference between technologies. DB1-R and HB1-P follow the same pattern, increasing emissions by increasing VSP Bin with a very different rate. HB1-P reaches its maximum value on Bin 13 at 0,05 g/sec, DB1-R reaches its maximum in Bin 14 at 0,18 [g/sec], on Bin 14 HB1-P NOX emission reductions is 87% versus DB1-R. In general terms, HB2-S shows the same behaviour as expected, with almost the same emissions for every VSP Bin, even though emissions on Bins 9 to 11 are still higher than DB1-R.

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Figure 3.6. NOx per VSP-Bin Rio de Janeiro

Average PM1.5 emissions have a different tendency than other pollutants; HB1-P emissions are the lowest for every VSP Bin, with a maximum of 77% reduction over DB1-R in Bin 11. HB2-S reported the highest emissions; on average for all Bins HB2-S is 33% higher than DB1-R. The VSP Bin with the highest difference is Bin 11 with 117% more PM1.5 emissions than DB1-R, normally this VSP Bin is the one with most time percentage in urban driving.

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Figure 3.7. PM1.5 per VSP-Bin Rio de Janeiro

3.2.2 Sao Paulo The second city where the tests were performed was Sao Paulo. Four buses were tested in two rounds: a reference diesel bus (DB1-R), an articulated diesel bus (DB2-A) and two hybrids, a parallel hybrid bus (HB1-P) and a serial hybrid bus (HB2-S). The next graphs show emissions in grams per second by energy demand (VSP Bins), this methodology is used according to the International Vehicle Emission (IVE) model, as mention previously in this report: Bin 11 represents energy demand near idling, Bin 9 and 10 represent energy demand when the vehicle is decelerating and Bin 12 to 14 represent energy demand when the vehicle is accelerating. In the case of CO2 emissions, there is an increase for all buses when the energy demand increases as expected, from Bin 9 to 11 all buses show comparable results, except for HB2-S showing high emissions for lower VSP Bins, this high emissions on lower energy situations are related with the HB2-S configuration, this bus is a series hybrid which means that the internal combustion engine is always running, normally charging batteries. This can result in high emissions when the bus is idling or decelerating. From Bin 11 differences appear between buses. For HB1-P emissions are 25% lower and for HB2-S are 5% higher. In Bin 12 HB1-P shows a 31% reduction and HB2-S shows a 27% reduction for the same energy situation. For Bin 13 HB1-P shows a reduction of 16% and for Bin 14 it shows no reduction against DB1-R, HB2-S shows 53% reduction for Bin 13 and 52% for Bin 14.

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DB2-A emissions are almost the same that DB1-R for Bins 9 to 11, while for VSP-Bins 12 and 13 emissions are 21% and 18% higher than DB1-R respectively.

Figure 3.8. CO2 per VSP-Bin Sao Paulo

With respect to NOx emissions, energy demand analysis shows that the difference between technologies, DB1-R, HB1-P and HB2-S, follow the same pattern, increasing emissions by increasing VSP Bin number, however the rates are different. It is noticeable that HB2-S being a series hybrid is showing a similar pattern, this is possible considering that the bus regulating RPM of the engines under load conditions. While HB1-P reaches its maximum value on Bin 14 at 0.13 g/sec, DB1-R reaches its maximum also in Bin 14 at 0.18 [g/sec]; this means a reduction of 31% for NOx emissions at the maximum level. HB2-S is below both results, reaching a maximum of 0.07 g/sec on Bin 14, which indicates a 59% emissions reduction against DB1-R for the maximum level. Interesting enough, DB2-A NOX emissions are lower than DB1-R emissions, for Bins 12 and 13, and for the rest of the Bins DB2-A emissions are very comparable between each other.

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Figure 3.9. NOx per VSP-Bin Sao Paulo

PM1.5 emissions per VSP-Bin show important differences between DB1-R, DB2-A and HB1-P7, DB1-R is the dirtiest one for almost every energy demand situation while HB1-P is the lowest. In average, PM1.5 emissions reductions are 68% for all VSP Bin, in BIN 13 the main gap appears with a difference of 72% between DB1 and HB1-P. DB2-A shows a 28% average PM1.5 reduction for all VSP Bins in comparison with DB1-R, although DB1-R is a smaller bus, this fact is explained due to DB2-A electronic which is more advance than DB1-R.

7  HB2-­‐S  PM1.5  emissions  were  not  measure  due  to  PM  equipment  problems.  

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Figure 3.10. PM1.5 per VSP-Bin Sao Paulo

3.2.3 Bogota In Bogota, Colombia, once again four buses were tested, a diesel reference bus (DB1-R), two Parallel hybrids buses (HB1-P and HB2-P) and a Full Electric Bus (EB1). The following graphs show emissions in grams per second divided by energy demand (VSP Bins), this methodology is used according to the IVE model and is highly recommended to read the Annex related with this methodology on the report to better understand this section results. Basically, Bin 11 represents energy demand near idling, Bin 9 and 10 represent energy demand when the vehicle is slowing down and Bin 12 to 14 represent energy demand when the vehicle is accelerating. With respect to CO2 emissions, it is interesting how for all buses there is a similar trend when energy demand increases as expected, from Bin 9 to 10 all buses show very comparable results. From Bin 11 differences appear between buses, for HB1-P emissions are 35% lower and for HB2-P the reduction is 11% in comparison with HB2-P. In Bin 12 HB1-P shows a 19% reduction and HB2 shows a 31% reduction for the same energy situation, once again respect DB1-R. For Bin 13 and 14 HB1-P shows little or non reduction against DB1-P, HB2 shows 20% reduction for Bin 13 and 11% for Bin 14. Normally, the most of the time for urban conditions is spent in Bin 11; this is why HB1-P still may have an advantage over HB2-P although on the rest of the energy situations CO2 emissions are higher.

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Figure 3.11. CO2 per VSP-Bin Bogotá

For NOx emissions, energy demand analysis shows the difference between technologies once again in Bogota’s altitude (2600 mt). Emissions from DB1-R, HB1-P and HB2-P follow the same pattern, increasing by increasing Bin number and once again rates are very different. While HB1-P reaches its maximum value in Bin 14 at 0.026 g/sec, DB1 reaches its maximum in Bin 14 at 0.23 [g/sec], meaning there is a reduction of 93% in NOx emissions at the maximum level. On average, NOx reductions for all VSP Bins are 78% for HB1-P compared with DB1-R. HB2-P is in between both results, reaching a maximum of 0.095 g/sec on Bin 14, which indicates a 58% emissions reduction against DB1 for the maximum level. On average, NOx reduction for all VSP Bins is 37% for HB2-P compared with DB1-R.

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Figure 3.12. NOx per VSP-Bin Bogotá

PM emissions per Bin show important differences between the standard bus and hybrids buses, DB1-R is dirtier for almost every energy demand situation than both hybrids buses. On Bin 14 the main gap appears with a difference of 86% between DB1 and HB1. HB2 shows a difference of 83%, both hybrids shows very comparable results. In average, reduction from both hybrids is 64% compared with DB1-R.

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Figure 3.13. PM1.5 per VSP-Bin Bogotá

3.2.4 Santiago The last campaign was performed in Santiago, Chile, once again four buses were tested, a reference diesel bus (DB1-R), a diesel equipped with diesel particle filter (DB2-F), a hybrid bus (HB1-P) and a Full Electric Bus (EB1). This last bus was not reported in this section due to obvious reasons. The next images show emissions in grams per second classified by energy demand (Bins), as in rest of the program this methodology is used according to the IVE model8. In terms of driving dynamic Bin 11 represents energy demand near idling, Bin 9 and 10 represent energy demand when the vehicle is decelerating and Bin 12 to 14 represent energy demand when the vehicle is accelerating. Analyzing CO2 emissions, the increase for all buses when the energy demand increases is consistent with other cities. From Bin 9 to 11 results show higher emissions for DB2-F and important differences appear from Bin 12 where DB1 shows higher emissions. Comparing DB1-R against DB2-F, CO2 emissions results are close as expected. For Bin 11 and Bin 14 DB2-F is higher by 7% and 11%. DB2 shows lower emissions on Bins 12 and 13 by 11% and 12%. Comparing HB1-P against DB1-R emissions for HB1 emissions are lower for all energy situations, from 68% on Bin 10 to 20% on Bin 14%. In average emissions reduction from HB1-P to DB1-R is 45%. 8  www.issrc.org  

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Figure 3.14. CO2 per VSP-Bin Santiago

In the case of NOX emissions, energy demand analysis explain the differences between technologies, DB1-R, DB2-F and HB1-P follow the same pattern, increasing emissions by increasing Bin number, and as seen during the entire program rates are different once again. HB1-P emissions reaches its maximum value in Bin 14 at 0.049 g/sec, in the same Bin DB1-R reaches its maximum at 0.29 [g/sec] and DB2-F reaches its maximum in Bin 14 at 0.31 [g/sec] meaning there is a reduction of 83% for NOX emissions at the maximum level from DB1-R compared to HB1-P. In averaged, there is 59% reduction for all Bins when comparing HB1-P to DB1-R. DB2-F shows an increase of NOx emissions against DB1-R of 21% from Bin 11 to Bin 14, this can be explained by the effect of the Diesel Particle Filter (DPF) counter-pressure on the engine. In fact, looking at average results, NOx emissions are the only pollutant where DB2-F show higher emissions compare with the reference bus (DB1-R).

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Figure 3.15. NOx per VSP-Bin Santiago

Santiago’s PM1.5 emissions per Bin provide an important technology comparison to the program: a diesel bus equipped with a diesel particle filter (DB2-F). In addition, Santiago has the cleaner diesel in the program, less than 50 ppm of sulfur. As expected, DB1-R is dirtier for every energy demand situation. HB1-P shows an emissions reduction of 72% in average for all Bins compared to DB1-R, main difference appear in Bin 10 with 85% reduction. The cleanest bus is DB2-F showing the lowest PM1.5 emissions, in average emissions reduction for all Bin situations reaches a 96% with emissions reductions from 91% on Bin 14 to 98% on Bin 10. This results show the high efficiency of diesel particle filters.

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Figure 3.16. PM1.5 per VSP-Bin Santiago

3.3 Normalized Emissions Results Finally, to directly compare average emissions results under the same driving pattern or driving behavior, normalized emissions are calculated. These emissions are calculated combining Phase 1 results with Phase 2 driving behavior results through vehicle specific power binning methodology, to evaluate every bus of each city under the same driving pattern represented by the over all driving cycle of a given city. In summary, with the GPS data collected in Phase 2 a representative driving cycle was developed for each city (see Chapter 3), this driving cycle include driving behavior, buses dynamics and traffics factor conditions that allows to normalized emissions by city. On the following sections normalized emissions are compared.

3.3.1 Rio de Janeiro As mentioned previously in this report, Rio de Janeiro was the first city to be tested; Table 3.2 shows raw results performed by bus in Rio de Janeiro for emissions and fuel consumption.

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Table 3.6 Normalized results of emissions and fuel consumption, Rio de Janeiro

ID BUS THC (g/km)

CO (g/km)

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CO2 (g/km)

PM1.5 (g/km)

FC Ph1 [L/100km]

FC Ph2 [L/100km]

DB1-R 0.13 6.23 11.32 1,230 0.13 46.67 33.33 HB1-P 0.07 1.47 5.89 1,243 0.06 47.14 30.03 HB2-S - 5.79 11.50 1,693 0.21 64.24 50.25

In summary, HB1-P performed with lower normalized emissions rates (g/km) than DB-R and average emission reduction was 46%, considering all pollutants measured. The greatest emission reduction result was in CO with 76%. In general, normalized emissions increase unitary emissions for most of the pollutants in HB1-P. Regarding NOx and PM1.5 in HB1-P, emissions normalized rates reached 5.89 (g/km) and 0.06 (g/km), which is equivalent to 48% and 56% emission reduction with respect to DB1-R bus, respectively. Normalized CO2 emissions were 1,230 (g/km) and 1,243 (g/km) for DB1-R bus and HB1-P bus, respectively; these results correspond to no reduction between HB1-P with respect to DB1-R bus. Results for fuel consumption (L/100km) in HB-P running under Phase 2 was 10% lower than DB-R bus. In the case of HB-S bus tested in Rio de Janeiro, in general, it performed with higher normalized emissions rates (g/km) than DB1-R bus and average emission increment was 24%, considering all pollutants9 measured. This result is better than raw emissions where the difference was 57% on average increase emissions over DB1-R. Figure 3.1 shows difference between diesel reference bus (DB-R) and hybrid buses tested in Rio de Janeiro, where raw results have been normalized in terms of DB-R emissions and fuel consumption results.

9  There  is  no  THC  measurement  for  HB-­‐S  in  Rio  de  Janeiro  

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Figure 3.17 Normalized results normalized in terms of DB-R in Rio de Janeiro

3.3.2 Sao Paulo As mention before in this chapter, the second city were the tests were performed was Sao Paulo; in a second campaign, emissions from a serial hybrid bus were added to the campaign analysis. Table 3.3 shows raw results performed by buses in Sao Paulo for emissions and fuel consumption.

Table 3.7 Normalized results of emissions and fuel consumption, Sao Paulo

ID BUS THC (g/km)

CO (g/km)

NOx (g/km)

CO2 (g/km)

PM1.5 (g/km)

FC Ph1 [L/100km]

FC Ph2 [L/100km]

DB1-R 0.174 7.91 12.33 1,363 0.28 51.73 65.23 DB2-A 0.156 6.16 12.77 1,584 0.10 60.09 75.43 HB1-P 0.082 1.06 7.12 1,063 0.09 40.34 37.92 HB2-S - 1.74 6.45 1,112 - 42.19 51.03

Hybrid buses, both parallel and serial configuration, produce lower normalized emissions rates (g/km) than DB1-R and average emission reductions were, considering all pollutants measured, 54% and 48% for HB1-P and HB2-S10, respectively. The greatest emission reduction results were in CO with 87% for HB1-P and 78% for HB2-S. Regarding NOX in hybrid technology, HB1-P and HB2-S normalized emissions rates reached 7.12 (g/km) and 6.45 (g/km), which is equivalent to 42% and 48% emission reduction with respect to DB1-R, respectively. In case of HB1-P, emissions reduction for PM1.5 was 67% lower than DB1-R bus and absolute values were 0.09 (g/km) for HB1-P bus and 0.28 (g/km) for DB1-R bus.

10  There  are  no  THC  and  PM1.5  measurements  for  HB-­‐S  in  Sao  Paulo  

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Normalized CO2 emissions were 1,363 (g/km), 1,063 (g/km) and 1,112 (g/km) for DB1-R bus, HB1-P bus and HB2-S bus, respectively, and equivalent HB1-P bus and HB2-S emission reductions were 22% and 18% with respect to DB1-R bus. Results for fuel consumption (L/100km) in Phase 2, HB1-P and HB1-S results were 42% and 22% lower than DB1-R bus. An articulated diesel bus DB2-A was tested in Sao Paulo, which produces higher NOx and CO2, normalized emissions rates than DB1-R bus with 4% and 16% of increment, respectively. On the other hand, DB2-A normalized results for CO and PM1.5 emissions were lower than DB1-R bus with 22% and 62% of reduction, respectively Figure 3.2 shows difference between diesel reference bus (DB1-R), hybrid buses (HB1-P and HB2-S) and articulated diesel bus (DB2-A) tested in Sao Paulo, where raw results have been normalized in terms of DB1-R emissions and fuel consumption results.

Figure 3.18 Normalized results normalized in terms of DB-R in Sao Paulo

3.3.3 Bogota As mentioned before, the first campaign after Brazil was performed in Bogotá, Colombia, 4 buses were tested, a reference diesel bus (DB1-R), 2 hybrid buses (HB1-P and HB2-P) and 1 full electric bus (EB). Table 3.8 shows raw results performed by bus in Bogota for emissions and fuel consumption.

Table 3.8 Normalized results of emissions and fuel consumption, Bogota

ID BUS THC (g/km)

CO (g/km)

NOx (g/km)

CO2 (g/km)

PM1.5 (g/km)

FC Ph1 [L/100km]

FC Ph2 [L/100km]

DB1-R 0.64 7.74 14.80 1,212 0.075 45.98 50.49

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HB1-P 0.04 3.34 2.05 967 0.027 36.69 33.57 HB2-P 0.02 3.90 5.96 907 0.020 34.39 34.46 As in previous cities, HB1-P buses produces lower normalized emissions rates (g/km) than DB1-R bus and average emission reduction was 63%, considering all pollutants measured in both hybrid buses: HB1-P and HB2-P. The greatest emission reduction results were in THC with 94% for HB1-P and 97% for HB2-P. Regarding normalized NOX in hybrid technology, HB1-P and HB2-P emissions rates reached 2.05 (g/km) and 5.96 (g/km), which is equivalent to 86% and 60% emission reduction with respect to DB1-R bus, respectively. Normalized emissions reductions for PM1.5 were 64% (HB1-P) and 73% (HB2-P) lower than DB-R bus and absolute values were 0.027 (g/km) for HB1-P, 0.020 (g/km) for HB2-P and 0.075 (g/km) for DB1-R. CO2 normalized emissions were 1,212 (g/km), 967 (g/km) and 907 (g/km) for DB1-R bus, HB1-P bus and HB2-P bus, respectively, and equivalent HB1-P bus and HB2-P emission reductions were 20% and 25% with respect to the DB1-R bus. This result is one of the unique results where normalized emissions show increased reductions. In this case, HB2-P increases its reduction by 13% (it was only 12% in the case of raw emissions) over raw results. This is possible considering that emissions per VSP Bin (Section 3.2.3) for HB2-P are lower than HB1-S for VSP-Bin 12 and 13. The normalized cycle is expending more time under this situation than the raw driving pattern. Results for fuel consumption (L/100km) in HB1-P and HB2-P results for Phase 2 were 34% and 32% lower than DB1-R bus. Figure 3.3 shows differences between diesel reference bus (DB1-R) and hybrid buses tested in Bogota, where raw results have been normalized in terms of DB1-R emissions and fuel consumption results.

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Figure 3.19 Normalized results normalized in terms of DB-R in Bogota

3.3.4 Santiago As mention before in this report, Santiago, Chile was the last city where tests were performed. In Santiago 4 buses were tested, once again only the buses with internal combustion engines are analysed in this sub section. In Santiago, a diesel bus equipped with a Diesel Particle Filter was tested and compared with the Hybrid bus. Table 3.9 shows raw results performed by bus in Santiago for emissions and fuel consumption.

Table 3.9 Normalized results of emissions and fuel consumption, Santiago

ID BUS THC (g/km)

CO (g/km)

NOx (g/km)

CO2 (g/km)

PM1.5 (g/km)

FC Ph1 [L/100km]

FC Ph2 [L/100km]

DB1-R 0.19 22.03 22.03 1,756 0.056 66.61 55.95 DB2-F 0.04 3.56 26.67 1,659 0.001 62.94 59.06 HB1-P 0.05 0.60 4.14 1,128 0.013 42.80 33.56 Once again, HB1-P normalized emissions rates (g/km) were lower than DB1-R normalized emissions rates. The average emission reduction was 73%, considering all pollutants measured. The greatest emission reduction result was for CO with a 97% reduction. With respect to normalized NOx and PM1.5 emissions for HB1-P, emissions rates reached 4.14 (g/km) and 0.013 (g/km), which is equivalent to 81% and 78% emission reduction with respect to DB1-R, respectively. Normalized CO2 emissions were 1,756 (g/km) and 1,128 (g/km) for DB1-R bus and HB1-P bus, respectively, and equivalent HB1-P bus emission reduction was 36% with

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respect to DB1-R bus. Results for fuel consumption (L/100km) in HB1-P running under Phase 1 methodology were 35% lower than DB1-R bus. Analogue HB1-P result for Phase 2 was 40% lower than DB1-R bus. A diesel bus with particulate filter DB-R was tested in Santiago, which produces less emission rates than DB1-R bus in all pollutants with exception of NOX. PM1.5 emission reduction was 98% and reached 0.001 (g/km). However, NOX emissions increased 21% and reached 26.67 (g/km). Regarding CO2 emissions, DB1-F reduced 6% with respect to DB-R, equivalent to 1,659 (g/km). Figure 3.1 shows difference between diesel reference bus (DB-R) and hybrid buses tested in Rio de Janeiro, where raw results have been normalized in terms of DB-R emissions and fuel consumption results.

Figure 3.20 Normalized results normalized in terms of DB-R in Santiago

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4 DISCUSSION AND CONCLUSIONS The Program involved 16 buses undergoing 30 hours of testing under real-world driving conditions, for emissions and energy consumption, running along bus routes defined by each participating city’s local authority and transport operators. Pioneering bus manufacturers, made buses available to the C40-CCI team for testing. Bus testing comprised different hybrid (diesel/electric) and full electric vehicles, compared against a diesel bus (reference case). Following detailed planning, ISSRC group took on the testing in each city. Three main testing components were measured to assess bus performance:

i. Direct exhaust emissions ii. Fuel and energy consumption

iii. Role of drivers, routes, topography and altitude The Program received the support of local bus operators and representatives in each city. Bus routes were identified by common agreement among the relevant representatives, and based on criteria such as specific local policies, normal operating conditions for public transport services, topography and maximum coverage of the main urban area. Tests were carried out under normal operating conditions at maximum loading capacity using simulated weights. The results from the technical phase of the Program show that adoption of hybrid buses could reduce CO2 emissions by up to 35% (26% on average) compared to the reference diesel buses. Average reductions in local emissions of between 60-80% were achieved, alongside a 30% reduction in fuel consumption. Electric buses emit almost no local emissions and offer up to 77% reduction in energy consumption based on electricity compared with diesel.

4.1 Exhaust Emissions The Program tested several emissions components for diesel-only and hybrid diesel-electric buses (full electric buses are not included in this analysis since this technology has zero direct exhaust pipe emissions). Results varied by city, as described below, but in all cases emissions performance was higher for parallel hybrid buses than traditional diesel buses. Several hybrid technologies and diesel-only buses were tested in the four cities participating in the Program. Both Brazilian cities presented two hybrid technologies, a serial and a parallel bus; Bogota participated with two parallel hybrid technologies; Santiago had one parallel hybrid bus. In Bogota and Santiago electric buses were tested and a trolley was evaluated in Sao Paulo. Figure 1 compares CO2 and criteria pollutant reduction emissions for parallel-hybrid technologies and the respective reference diesel bus, for the four cities participating in the Program. On average, parallel-hybrid bus technologies registered 25% lower CO2 emissions than the standard diesel technology, under comparable weights, routes and

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traffic conditions (all results have been normalized using a common driving cycle). For criteria pollutants, when comparing parallel-hybrid versus diesel-only technologies, average reductions were 61% for nitrogen oxides, 72% for fine particle matter, 72% for unburnt hydrocarbons and 79% for carbon monoxide.

Figure 4.1 Emissions reductions for carbon dioxide and criteria pollutants

One bus manufacturer made available its parallel-hybrid technology in all four cities; the grey bars indicate how the technology improved over time. In Bogota there were two parallel-hybrid technology vehicles being tested within the Program; they show relatively similar reductions compared with the reference diesel bus. Thus, the values for Bogota shown above are the averages of the two bus providers; for the other three cities the bus manufacturer was the same. Emission reductions for gases and fine particle matter were always greater than 50% for all parallel and improved-serial hybrid technologies, with increased performance of over 70% reduction in all criteria pollutants analyzed. The results for PM1.5 are particularly interesting, showing an almost constant 72% reduction for all cities. These improvements would have important impact on local air quality, resulting in major health benefits (the combined population of the four cities is around 50 million). Introducing economic valuations based on health impact analysis, and assuming fleet turnovers in favor of hybrid technologies, should be considered part of an assessment framework.

4.2 Energy and Fuel Efficiency The Program tested fuel consumption for diesel-only and hybrid diesel-electric buses, as well as electric energy consumption for full electric buses and a trolleybus. The analysis

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includes comparisons of fuel consumption by bus (FC) and by passenger (FC/pax), using a corresponding reference diesel bus in each city. Electric energy consumption is converted into equivalent liters of diesel fuel, as explained below. Four reference diesel, seven hybrid and three full electric vehicles were tested in the four cities participating in the Program. Reference diesel buses are denominated DB-R; hybrid buses are denominated HB-P and HB-S for parallel and serial technologies respectively; full-electric vehicles are EB whose equivalent fuel consumption is estimated by converting kWh and liters into kcal of energy to avoid distortions to or fluctuations in local energy market prices. Note that these acronyms do not necessarily refer to the same vehicles between cities. As already explained, the hybrid buses were provided by three different manufacturers, one serial (HB-S) and two parallel (HB-P) configurations, and in relation to the full-electric vehicles (EB), Sao Paulo provided a conventional in-use trolleybus, and in Bogota and Santiago brand new full-electric buses were tested, in the form of a single bus from a different manufacturer in each city. A representative diesel bus (DB-R) was identified at each location.

Figure 4.2Fuel and energy consumption results

Figure 2 shows that results vary by city, but in all cases energy efficiency from parallel-hybrid and full-electric buses was higher than for the traditional diesel bus. Average fuel consumption was 31% less for the parallel-hybrid technologies compared to the diesel bus. This increases to 38% if the value for Rio de Janeiro is excluded; it is assumed that the bus manufacturer providing this technology learned and improved during the Program following experience in Rio. Electric technologies showed differences between cities and vehicle types. An average 77% better fuel consumption was achieved in the two cities testing brand new electric buses (81% for Bogota and 73% for Santiago). Fuel consumption for the in-use trolleybus tested in Sao Paulo was 56% lower than for the diesel bus.

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Similar to the results for exhaust emissions, the fuel consumption results for the serial hybrid bus were poor compared to diesel in Rio de Janeiro (+51%) but improved and were better than diesel in Sao Paulo (-22%). This improvement could be due to a learning process triggered by this Program, which might be ongoing and could produce better results. The values reported above change when calculated as consumption per passenger due to the smaller passenger capacity of electric compared to diesel-only vehicles. Diesel buses have a larger passenger capacity given their comparatively lighter weight. Hybrid buses have a 10-20% smaller capacity than diesel buses, and electric buses can accommodate 40-50% fewer passengers, due mainly to the extra load of the huge battery packs. Figure 3 shows fuel and equivalent energy consumption per passenger.

Figure 4.3 Fuel and energy consumption results per passenger

The serial hybrid technologies maintain their benefits, with 29% average reduction compared with the diesel buses. Electric buses lose some of their advantage over the reference diesel bus, going from 77% average reduction to 61% taking account of load carrying capacity. Local operators were concerned about the smaller passenger capacity of the new and cleaner technologies, not only because of the reduced benefit in energy savings but also on operational logistical grounds. This is a problem that low carbon technology bus manufacturers are tackling.

4.3 Key Findings and Recommendations

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Page 53: Resultados C40 en Latinoamérica

Santiago  Report  for  C40-­‐CCI-­‐IDB  Hybrid  Electric  Bus  Test  Program  in  Latin  America  

International  Sustainable  Systems  Research  Center   45  

4.3.1 Key findings and recommendations for stakeholders The Program has demonstrated the significant effects of hybrid and electric buses compared with conventional diesel vehicles:

i) Reductions in GHG and emissions of criteria pollutants including especially PM1.5,which shows reductions of 75% on average;

ii) Reductions in CO2 emissions of 26% on average; iii) More efficient fuel consumption based on reductions of between 31% and

40% depending on altitude in the case of hybrid-electric buses, and up to 77% in the case of full electric battery powered buses (equivalent fuel consumption).

The Program found also that:

i) Driving patterns, driver competence, and steepness of the terrain affect the performance of low carbon buses;

ii) Ten-year life-cycle analysis of hybrid and electric buses results in lower net present value compared to conventional diesel buses, for several scenarios;

This is evidence that these technologies can compete with conventional buses with some initial incentives, financing arrangements, and creative business models for the electric vehicle components.

4.3.2 Key recommendations Bus manufacturers should be encouraged to pay attention to current regulation and work to adapt their products to the Latin American market directives especially regarding vehicle weights, which can have a negative effect on economic evaluations of bus operations. Suppliers should be invited to participate in the development of financial solutions to facilitate the acquisition of these new vehicles by city bus operators. Cities and national governments should be encouraged to introduce and maintain certain incentives, such as low or zero VAT, import duty, and local taxes, in order to facilitate the initial uptake of low carbon vehicles. Given the positive effect of the new technologies on population health and health sector costs, governments should contribute to the initial capital costs, for example, through direct subsidies or by allowing marginal increases to fares. Diesel prices should be corrected to reflect the real price of the fuel and pollution taxes should be imposed on this energy source. Cities in Latin America are responsible for the renewal of their bus fleets, representing purchase of some 9,000 buses by 2020. Old vehicles should be scrapped and replaced by low carbon technologies. Governments should develop, implement, and enforce strict fuel performance regulations for buses to encourage the building of clean public

Page 54: Resultados C40 en Latinoamérica

Santiago  Report  for  C40-­‐CCI-­‐IDB  Hybrid  Electric  Bus  Test  Program  in  Latin  America  

International  Sustainable  Systems  Research  Center     46  

transportation. The data provided by the Program are strong and persuasive. They propose firm benchmarks that cities can apply with confidence when setting regulation. In summary, Latin American cities have a great opportunity to drive the markets for low carbon transport technologies, and particularly hybrid and electric buses. The economic effort required will be far outweighed by the large environmental and health benefits that will accrue. Both the IDB and C40-CCI have a deep commitment to helping lead cities to move their transport sectors to the frontier in low carbon sustainable mobility.