Estimating the Energy Demand and Carbon Emission Reduction Potential of Singapore’s Future Road Transport Sector
Abstract
:1. Introduction
1.1. Background
- -
- Achieve 90% peak hour journeys on walk-cycle-ride modes by 2040;
- -
- Achieve 100% cleaner energy vehicles by 2040 [4];
- -
- Expand charging infrastructure for electric vehicles (EVs), especially in public car parks.
1.2. Singapore’s Transport Policies
1.3. Contribution of Paper
- Establishment of an estimate of the present and future energy demand of Singapore’s road transport (80%) by 2040 after the 100% electrification policy is in full motion;
- Derivations of the grid emission factors based on six defined power generation mix scenarios;
- Presentation of potential emission reductions based on six power generation scenarios;
- Provision on recommendations on the optimal pathway towards decarbonization of the transportation sector.
2. Literature Review
3. Methodology and Data Collection
3.1. Methodology
- Establish a set of vehicle parameter databases for each vehicle type for the present time (i.e., vehicle population, fuel consumption, etc.);
- Derive the present energy demand of each of the nine vehicle sub-classes;
- Establish the petrol/diesel emission factors;
- Derive present carbon emissions using the values from steps 2 and 3;
- Establish a set of vehicle parameter databases and assumptions for each vehicle sub-class for 2040;
- Derive the 2040 energy demand of each of the nine vehicle sub-classes;
- Establish the power generation mix scenario policies to derive the grid emission factors;
- Derive the 2040 carbon emissions based on the various emission factors from 7;
- Compute the energy demand reduction from steps 2 and 6;
- Compute the potential carbon emission reduction from steps 4 and 8 across the scenarios.
3.2. Theory
3.2.1. Present Energy Demand
3.2.2. Energy Demand in 2040
3.2.3. Present and 2040 Carbon Emissions
3.3. Data collection
3.3.1. Fuel Emission Factor
3.3.2. Vehicle and Fuel Data
3.4. Scenario Definitions
3.4.1. Power Generation Mix Scenarios
3.4.2. Vehicle Class-Based Electrification Scenarios
4. Results
4.1. Present vs. 2040 Energy Demand
4.2. Scenario-Based Analysis
5. Discussion
6. Conclusions
- (1)
- Electrifying all nine road transport vehicle sub-classes is projected to reduce energy demand by 69.33 ± 7.57% on average. This substantial reduction can be primarily attributed to enhanced vehicle efficiencies associated with electrification.
- (2)
- Even with the current power generation mix, the complete electrification of all nine vehicle sub-classes could mitigate 46.90 ± 13.10% of carbon emissions, highlighting the immediate environmental benefits achievable through electrification.
- (3)
- In the optimal scenario where 100% electrification is coupled with low-carbon technologies integrated into the power system, the potential for emission reduction significantly increases to 89.30 ± 2.64%. This reflects the importance of synergistic approaches to achieving substantial reductions in carbon emissions.
- (4)
- The research identifies two primary pathways for decarbonizing road transport: complete electrification of vehicle fleets and adoption of low-carbon energy carriers within the power system. These pathways offer promising strategies for achieving sustainable and environmentally friendly transportation systems.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
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Transport Sub-Class | Fuel Used | Energy Consumption (L/100 km): ICE | Energy Consumption (Wh/km): EV | Average Daily Mileage (km) | Population |
---|---|---|---|---|---|
Public Buses (SD) | Diesel | 50 [22] | 1600 [22] | 201.55 [22] | 3805 [22] |
Public Buses (DD) | Diesel | 55 [22] | 2300 [22] | 201.55 [22] | 1629 [22] |
Public Buses (AB) | Diesel | 60 [22] | 2500 [22] | 201.55 [22] | 430 [22] |
Ride-hail | Petrol (~70%) | 3.7 [23] | 115 [23] | 230 [24] | 60,701 [2] |
Ride-hail | Diesel (~30%) | 6.1 [23] | 115 [23] | 230 [24] | 26,015 [2] |
Private Cars | Petrol | 7.6 [25] | 166 [26] | 47.95 [27] | 567,457 [2] |
Motorcycles | Petrol | 1.9 [28] | 50 [28] | 35.62 [27] | 142,453 [2] |
Road Freight (GPV) | Diesel | 7.77 [23] | 277 [23] | 109.59 [27] | 2603 [2] |
Road Freight (LGV) | Diesel | 8.94 [12] | 277 [23] | 109.59 [27] | 96,514 [2] |
Energy Scenario | Energy Source | Percentage of Power Generation Mix | Emission Factor (kgCO2/kWh) | Weighted Emission Factor (kgCO2/kWh) |
---|---|---|---|---|
Scenario 0: Constant energy mix | Natural gas | 94.3 | 0.440 [35] | 0.415 |
Solar and municipal energy waste | 4.4 | 0.048 [36] | 0.002 | |
Coal | 0.9 | 0.820 [36] | 0.007 | |
Petroleum products | 0.3 | 1.080 [35] | 0.003 | |
Overall | 100 | - | 0.428 | |
Scenario 1: Diversified Mix [31] | Electricity Imports | 40.0 | 0.110 [30] | 0.044 |
Low-carbon hydrogen | 40.0 | 0.094 * | 0.038 | |
Solar | 6.0 | 0.020 [37] | 0.001 | |
Geothermal | 12.0 | 0.038 [36] | 0.005 | |
Others | 2.0 | 0.390 [35] | 0.008 | |
Overall | 100 | - | 0.095 | |
Scenario 2: Electricity Imports Dominated [31] | Electricity imports | 60.0 | 0.110 [30] | 0.060 |
Low-carbon hydrogen | 10.0 | 0.094 * | 0.009 | |
Natural gas | 12.0 | 0.440 [35] | 0.053 | |
Solar | 8.0 | 0.020 [37] | 0.002 | |
Geothermal | 8.0 | 0.038 [36] | 0.003 | |
Others | 2.0 | 0.390 [35] | 0.008 | |
Overall | 100 | - | 0.141 | |
Scenario 3: Low-carbon Hydrogen [31] | Low-carbon hydrogen | 55.0 | 0.094 * | 0.052 |
Electricity imports | 25.0 | 0.110 [30] | 0.025 | |
Solar | 8.0 | 0.020 [37] | 0.002 | |
Geothermal | 1.0 | 0.038 [36] | 0.000 | |
Nuclear | 10.0 | 0.012 [36] | 0.001 | |
Others | 1.0 | 0.390 [35] | 0.004 | |
Overall | 100 | - | 0.086 | |
Scenario 4: 2035 => 2040 [32] | Natural gas | 50.0 | 0.440 [35] | 0.220 |
Renewable energy imports | 30.0 | 0.110 [30] | 0.033 | |
Others | 20.0 | 0.390 [35] | 0.078 | |
Overall | 100 | - | 0.331 | |
Scenario 5: 30% Natural Gas | Electricity imports | 40.0 | 0.110 [30] | 0.044 |
Low-carbon hydrogen | 10.0 | 0.094 * | 0.038 | |
Natural gas | 30.0 | 0.440 [35] | 0.044 | |
Solar | 6.0 | 0.020 [37] | 0.001 | |
Geothermal | 12.0 | 0.038 [36] | 0.005 | |
Others | 2.0 | 0.390 [35] | 0.008 | |
Overall | 100 | - | 0.139 |
Transport Type | Present Energy Demand (ktoe) | Energy Demand in 2040 (ktoe) | Energy Demand Reduction (%) |
---|---|---|---|
Public Buses (SD) | 123.54 | 38.50 | 68.83 |
Public Buses (DD) | 58.20 | 23.70 | 59.27 |
Public Buses (AB) | 16.75 | 6.80 | 59.42 |
Ride-hail (Petrol) | 160.09 | 50.39 | 68.53 |
Ride-hail (Diesel) | 117.60 | 21.60 | 81.64 |
Private Cars | 640.89 | 141.76 | 77.88 |
Motorcycles | 29.88 | 7.96 | 73.35 |
Road Freight (GPV) | 7.14 | 2.48 | 65.28 |
Road Freight (LGV) | 304.68 | 91.95 | 69.82 |
Vehicle Sub-Class | Scenario 0 | Scenario 1 | Scenario 2 | Scenario 3 | Scenario 4 | Scenario 5 |
---|---|---|---|---|---|---|
Public Buses (SD) | 46.40 | 88.08 | 82.39 | 89.20 | 58.55 | 82.58 |
Public Buses (DD) | 29.95 | 84.43 | 76.99 | 85.88 | 45.84 | 77.23 |
Public Buses (AB) | 30.20 | 84.48 | 77.07 | 85.93 | 46.03 | 77.31 |
Ride-hail (Petrol) | 42.65 | 87.25 | 81.16 | 88.44 | 55.66 | 81.36 |
Ride-hail (Diesel) | 68.42 | 92.98 | 89.63 | 93.64 | 75.58 | 89.73 |
Private Cars | 61.96 | 91.54 | 87.50 | 92.33 | 70.59 | 87.63 |
Motorcycles | 54.17 | 89.81 | 84.94 | 90.76 | 64.56 | 85.10 |
Road Freight (GPV) | 40.28 | 86.73 | 80.38 | 87.96 | 53.83 | 80.59 |
Road Freight (LGV) | 48.10 | 88.46 | 82.95 | 89.54 | 59.87 | 83.13 |
Aggregated Reduction | 54.31 | 89.84 | 84.99 | 90.79 | 64.67 | 85.15 |
Vehicle Class | Scenario 0 | Scenario 1 | Scenario 2 | Scenario 3 | Scenario 4 | Scenario 5 |
---|---|---|---|---|---|---|
Public Buses | 5.50 | 11.87 | 11.00 | 12.04 | 7.36 | 11.03 |
Ride-hail | 10.00 | 16.64 | 15.73 | 16.81 | 11.93 | 15.76 |
Private Cars | 27.39 | 40.47 | 38.68 | 40.82 | 31.20 | 38.74 |
Motorcycles | 1.12 | 1.85 | 1.75 | 1.87 | 1.33 | 1.75 |
Road Freight | 10.31 | 19.02 | 17.83 | 19.25 | 12.85 | 17.87 |
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Devihosur, S.C.; Chidire, A.; Massier, T.; Hamacher, T. Estimating the Energy Demand and Carbon Emission Reduction Potential of Singapore’s Future Road Transport Sector. Sustainability 2024, 16, 4754. https://doi.org/10.3390/su16114754
Devihosur SC, Chidire A, Massier T, Hamacher T. Estimating the Energy Demand and Carbon Emission Reduction Potential of Singapore’s Future Road Transport Sector. Sustainability. 2024; 16(11):4754. https://doi.org/10.3390/su16114754
Chicago/Turabian StyleDevihosur, Shiddalingeshwar Channabasappa, Anurag Chidire, Tobias Massier, and Thomas Hamacher. 2024. "Estimating the Energy Demand and Carbon Emission Reduction Potential of Singapore’s Future Road Transport Sector" Sustainability 16, no. 11: 4754. https://doi.org/10.3390/su16114754