Efficiency Study of Substitution of Official Vehicles in Banten Province with EVs (Electric Vehicle) To Reduce Carbon Emissions

To support the NDC (National Determined Contribution) targets in reducing greenhouse gas (GHG) emissions by 31.89% in 2030, the Presidential Instruction No. 7 of 2022 has been issued, which aims to replace conventional oil-fuelled vehicles in government official vehicles with electric vehicles (EVs). Although EVs do not directly produce GHG emissions as their engines do not involve fuel combustion, they still use electricity produced by Perusahaan Listrik Nasional (PLN), which uses fossil fuels in its combustion process. The purpose of this paper is to compare and determine whether the implementation of the new policy would have a significant impact on reducing GHG, particularly carbon emission, or not. This study therefore focused on calculating the indirect carbon emissions generated from the use of EVs compared to direct carbon emissions resulting from the use of official vehicles that run on fossil fuels in the Banten Province and Serang Regency. The carbon emissions in EVs are calculated using data from PLN’s carbon emissions from electricity production, while data on vehicle fuel usage and mileage per year are used to calculate emissions from official vehicles. The calculation methods were based on the 2006 IPCC (Intergovernmental Panel on Climate Change) document. The results of this study suggested that the efficiency of substituting official vehicles from oil-fuelled vehicles to the EVs, is dependent on the number and type of replaced vehicles. In both Banten Province and Serang Regency, the most efficient partial substitution of official vehicles was achieved by replacing official service vehicles with EVs, resulting in the reduction percentages of carbon emission by 26.73% and 28.58%, respectively.


Introduction
In Indonesia's NDC (National Determined Contribution) document issued in 2017 and then corrected in 2022, it is stated that Indonesia is committed to reducing greenhouse gas (GHG) emissions by 31.89%under Business As Usual (BAU) in 2030 and up to 43.2 % with international assistance.The NDC describes five sector categories and the proportion of their contribution to efforts to reduce GHG emissions, namely: forestry, energy, agriculture, industry, and waste.In efforts to reduce GHG 1307 (2024) 012003 IOP Publishing doi:10.1088/1755-1315/1307/1/012003 2 emissions, support in the form of soft technology and hard technology interventions is an aspect that must be met, one of which is low-emission technology innovation.
Transportation using motor vehicles is one of the primary sources of air pollution.The transportation sector produces a relatively significant amount of carbon emission from the combustion process that occurs in vehicle internal engine.The gas exhausted from oil fuel combustion contains contaminants such as CO2, (Carbon Dioxide), NOx (Nitrogen Oxide), CO (Carbon Monoxide), VHC (Volatile Hydrocarbon), and other particles; Emission that is most influential is emission from CO2 pollutants that have the most significant contribution to global warming and climate change [1].The accumulation of carbon dioxide emissions in the air can have an impact, namely the greenhouse effect which also has long-term effects on life because it is one of the triggers for global warming which can then lead to climate change [2].
Electric Vehicles (EVs) is one of the technological innovations that can reduce carbon emissions generated from the transportation sector because the use of EVs don't directly generate carbon emissions or GHG.This type of vehicle does not emit exhaust pollutants, CO2, or nitrogen dioxide (NO2).In addition, the manufacturing process of EVs tends to be more environmentally friendly than conventional vehicles [3].Many countries have implemented the use of New Electric Vehicles (NEVs) as an alternative to conventional vehicles to reduce dependence on oil and the resulting air pollution.In Indonesia itself, Presidential Instruction Number 7 of 2022 has been issued concerning the Use of Battery Electric Vehicles (BEVs) as Operational Service Vehicles and/or Individual Vehicles for Service of Central Government Agencies and Regional Governments, to reduce the use of conventional vehicles and replace them with BEVs [4].
The carbon emissions produced directly by EVs are far less than conventional vehicles.Based on data released by the Ministry of Energy and Mineral Resources in 2017, it was stated that EVs' carbon emissions were 0 g/km, while hybrid type EVs ranged from 70-80 g/km, and plug-in hybrid type EVs ranged from 45-50 g/km.As a comparison, the carbon emissions of conventional vehicles (gasolinefueled cars) produce carbon emissions of 125 g/km.The difference in carbon emissions is quite significant, however, the main source of electricity for BEVs is obtained from PLN, some of which still use coal as a production raw material.On a national scale, PLN contributes 14% of carbon emissions to the total national carbon emissions in 2021 [5].
For this reason, this research was conducted to examine how the amount of carbon emissions produced by conventional vehicles and carbon emissions indirectly generated by EVs electricity sources differ and how this would translate when applied to official vehicles following the newly issued policy because EVs' carbon emissions are not entirely zero (0 g/km) when used as a substitute for conventional vehicles.This study fills the gap in the research of EVs related emission studies by considering the usage of conventional vehicles as its counterpart, making use of Indonesia's new Presidential Instruction as its basis.

Data Collection
The data used in this study were primary and secondary data.Primary data was obtained directly from the field, which is data on distance covered by official vehicles.Secondary data in this study is in the form of EV data and specifications, including electricity consumption data obtained from electric vehicle vendor sites [6][7][8][9][10][11][12][13][14][15]; Serang Regency official vehicle data from BPKAD in the form of accumulation of Serang Regency official vehicle latest registered data of 2022 with the total of 2524 vehicles, and the Banten Province official vehicle data obtained from the BPS (Central Statistics Agency) for 2023 which summarizes the latest data, namely 2022 with the total of 27118 vehicles; as well as fuel consumption data for conventional vehicles [16][17].There are a lot of EV types but not every conventional vehicle has its electric version, thus not all of the vehicle types used as official vehicles can be substituted by EVs.The official vehicle data used in this study are only the ones that has EVs as a substitute which are shown in Table 1 and 2   Official vehicles consist of two categories, one is official service vehicles (kendaraan dinas jabatan, KDJ) and the other is operational service vehicles (kendaraan dinas operasional, KDO).KDJ are stateowned individual motorized vehicles that are used to carry out the duties of state officials and structural officials.While KDO consists of two parts which are specific operational service vehicles used for special government service facilities such as ambulance and field operational service vehicles used for field operational activities and services to the community and intended for employees who carry out field assignments.KDJ makes up about 30% of the total of official vehicles while the remaining 70% are KDO.Only about 7% of KDO are specific operational service vehicles and the rest, more than 90% of KDO are field operational service vehicles.

Conventional Vehicle Carbon Emission Calculation. Conventional vehicle carbon emissions
were calculated by multiplying the emission factor by the vehicle's fuel consumption.Calculations were done for each type of vehicle by grouping them according to the type of fuel used.There are several equations used in this calculation, which are as follows  These equations were used in stages to calculate conventional vehicle carbon emissions per year.To simplify the calculations, the equations was combined into one as follows This equation generally can be used to calculate conventional vehicle's carbon emission, but it can be further simplified according to the type of fuel used for different types of vehicles.Types of fuel for vehicles are divided into two, gasoline and diesel, and the emission factor and calorific value for both types of fuel are constants [18] with the following values shown in Table 3. PLN's carbon emission factor was taken directly from RUPTL PLN where in 2023 the newest record is 0.87 kg CO2/kWh [19].However, this value can change every year in line with PLN's steps to reduce carbon emissions resulting from the production process.

Calculation of carbon emission reduction from substitution of conventional vehicles with EVs.
This calculation was done by grouping certain types of EVs with conventional vehicles used as official vehicles, then reducing the carbon emissions of conventional vehicles and EVs per group.The result of the calculation is the reduced value.The reduction rate is converted into a percentage to give an idea of the emission reduction value obtained by the following equation Reduction Value = The difference between conventional vehicle carbon emissions and EVs carbon emissions (ton CO2/year) E Conventional Vehicle = Conventional Vehicle Carbon Emission (ton CO2/year)

Comparison between EVs and conventional vehicle.
Comparison was made to the value of carbon emissions.The values obtained from data processing are mapped in a side-by-side table and analysed starting from the size of the difference in emission values to which type of EVs has the greatest or smallest reduction level.

Calculation of Efficiency of Substitution of Conventional Vehicles with
EVs.The efficiency referred to was in the form of the difference in carbon emissions of official vehicles before and after substitution by EVs.This substitution is carried out in several scenarios.Efficiency statements will be presented in the form of reduced carbon emissions converted into percentages to provide an overview of the level of efficiency obtained.The equation used to find the percentage value is as follows E0 = Total Carbon Emission of Official Vehicle (ton CO2/year) Ex = Total carbon emission after substitution according to used scenario (ton CO2/year)

Conventional Vehicle Carbon Emissions
The data needed in calculating carbon emissions are fuel consumption data [16 -17] and data of average distance covered by official vehicles in a year.Calculations were performed using equation ( 5) and the results can be seen in Table 4 as follows From Table 4 above, information on carbon emissions for each type of conventional vehicle is obtained.For example, for an MPV, which is 3.70 -3.88 tons of CO2/year for a distance of 14400 km, and so on.It can also be seen that the greater the fuel consumption value of a vehicle or in other words the more distance travelled by the vehicle with 1L of fuel, the less vehicle emissions will be produced.This result is in line with other study that calculates conventional vehicle emission with the same fuel consumption data [20].Because there are 2 energy consumption data, 2 emission results are also obtained.The emission results obtained are considered as a range because one type of vehicle can produce different emission values.

EVs Carbon Emissions
Based on the existing types of official vehicles, it is known that these types of EVs are needed for the substitution of official vehicles from conventional vehicles to EVs.In several regions in Indonesia this substitution policy has been implemented so that it's assumed that the brand and type of EVs used in these regions will also be used in Banten Province.While there are several types of vehicles such as vans that have not implemented their replacement, EVs from these types of vehicles have been sold in the Indonesian market [21][22][23][24] therefore, it can be considered as one of the candidate for substitution.Calculation of carbon emissions was done using equation ( 6) and the results can be seen in Table 5.
Tabel As seen on Table 5, carbon emission of an EV depends on its energy consumption.A study suggests that higher energy consumption results in higher emissions and EVs generally have more efficient energy consumption than conventional vehicles [25].Distance also has a part in the calculation, the farther a vehicle go, the more emission it emits.But the total of distance covered in a year differs for different type of vehicle, particularly official vehicles that have different usages.In the case of conventional vehicle, generally the amount of carbon emission depends on its energy consumption.For example, both Gesits and Viar Q1 are motorcycle with the same total distance per year, but Viar Q1 has higher carbon emission because it has higher energy consumption.

Carbon Emission Reduction of EVs Substitution
The results of calculating motorized vehicle carbon emissions in Table 4 can then be compared with EVs emissions in Table 5 to find out the value and percentage of the reduction which is calculated by equation (7).Several types of EVs recorded have more than one option for substituting conventional vehicles so that through the calculation of its reduction value it can be determined the most optimal brand and model of vehicle to be used as a substitute for official vehicles.MPV type vehicles have not been produced in the form of EVs, so instead other passenger vehicles are used as a substitute for MPV official vehicles.Passenger vehicles in question include SUVs, micro cars, and city cars.This choice of passenger vehicles was based on vehicle substitution already done in some part of government official vehicle in Indonesia, namely in Jakarta and Bandung.The calculation of carbon emission reduction by substituting conventional vehicles with several EVs are shown in Table 6 below.A study was conducted in Malaysia with Nissan Leaf and it was found that on roughly the similar distance used in this calculation, Nissan Leaf saved 80% of energy used in conventional vehicle [26].Although the previous section has shown that energy usage or energy consumption is linear with carbon emissions, there is a big gap of number here as in this calculation reduction percentage of Nissan Leaf to replace MPV conventional vehicle is 46.22%.This difference occurs because the afromentioned study includes idle time in the calculation, EVs won't produce a secondary emission during idle time unlike conventional vehicle that still has the machine running during idle time such as when theres a traffic or a traffic jam.From the calculations on Table 6, the model of EVs that had the most significant percentage reduction for each type of conventional vehicle can be seen and are listed on Table 7 as can be seen below.It can be seen from Table 7 that the reduction percentage of EVs usage replacing their conventional vehicle counterpart are mostly greater than 50%, except for sedan and bus.This is because the difference between carbon emissions is small thus the number of emission reductions isn't so great compared to the initial emission.Overall, substitution of conventional vehicles with EVs will result in a reduction of carbon emission.

Efficiency of Official Vehicle Substitution with EVs
The efficiency of substitution for official vehicles is determined by replacing the official vehicle with the appropriate EVs or the one with the highest reduction percentage, after which the emission value is compared to the initial emission of the official vehicle before the replacement is carried out.This substitution was modeled using several scenarios.Scenarios were determined based on INPRES No. 7 of 2022, discussions with the Head of Assets of Serang Regency BPKAD, and consideration of factual conditions in the field.Based on these matters the scenarios used include substitution of Before determining the efficiency of substitution based on these scenarios, it is necessary to know the total emissions of official vehicles prior to substitution.Total emissions were obtained by multiplying the number of vehicles per type in Table 1 and Table 2 and the emission values for these types of vehicles which have been calculated and described in Table 4. Emissions 0 or emissions before substitution for Serang Regency official vehicles are 2740.843tons CO2/year, while for Banten Province official vehicles it is 35618.5 tons CO2/year.Furthermore, the calculation of emissions after EVs substitution was carried out by multiplying the number of substituted vehicles with EVs emissions, then adding the emissions from non-substituted vehicles.The number of vehicles replaced follows Table 1 for Serang District and  The scenario with the highest number of substitute vehicles (scenario 1) is the most effective scenario with the highest percentage of reduction.Conversely, the scenario with the least number of substituted vehicles (scenario 4) has the smallest reduction percentage.But the effectiveness of substituting vehicles into EVs depends on more than just numbers.Scenario 5 has a reduction percentage of less than half of the reduction percentage of scenario 1 but the number of vehicles substituted is more than half of scenario 1.This is because in addition to the number, the effectiveness of substitution also depends on the type of vehicle.In scenario 5, 1,628 vehicles were substituted, most of which were 1,456 motorcycles.Motorcycles themselves produce the fewest emissions when compared to other types of vehicles, so their substitution with EVs has a smaller impact than other types of vehicle substitution, such as MPVs and SUVs.In Figure 1, scenario 1, 3, and 5 are shown to have higher substituted vehicle bar than the reduction percentage bar, in contrast to scenario 2 and 4.This shows that scenario 2 and 4 are actually a lot more efficient to be implemented in Serang Regency because replacing less vehicles resulted in more reduction percentage which means less carbon emissions.Similar to the case in Serang Regency, scenario 1 has the highest reduction percentage and vehicles substituted, and scenario 4 has the least.What differs in Banten Province is that unlike scenario 1 in Serang Regency, here in figure 2, it's shown that scenario 1 here has a higher reduction percentage than the amount of vehicle substitution.But in practice if it were to be implemented, scenario 2 is still preferable because it offers more reduction percentage with less effort of substituting the vehicles.
Both in Serang Regency and Banten Province, scenario 2 or official service vehicle substitution is the better choice as it proves to be the most efficient scenario.Scenario 2 substitutes about 30% vehicle of the total official vehicle and a study in Brazil [27] shows that replacing 30% of a fleet with EV would require an increase of 159 GWh/day, which means in terms of energy consumption substituting conventional vehicle with EV may not be all that beneficial even if it's efficient to reduce carbon emission.Another study [28] even stated that the use of fossil energy carriers for electricity production can strongly reduce the environmental benefit of EVs and even lead to an increase in GHG emissions.

Conclusions
The efficiency of substituting service vehicles with EVs depends on the number and type of vehicles being substituted.Substitution is more efficient if the reduction percentage is greater with the number of vehicles substituted being smaller and the type of vehicle being substituted with a greater reduction value.This is why it is more efficient to substitute a few MPV rather than much motorcycle because carbon emission from motorcycle is not that considerable in the first place and although motorcycle has 58.81% reduction percentage its only amounted to 0.26 ton CO2/year which is rather insignificant compared to MPV's 2.8 ton CO2/year.Based on the calculations, it appears that replacing official vehicle with EVs partially is best implemented with scenario 2 in which the substituted unit is official service vehicles.This applies to both Serang Regency and Banten Province with carbon emission reduction percentage of 26,73% and 28,58% respectively.As substituting official vehicles to EVs means more demand for electricity production, further study is reccomended to see how the increase of EVs correlates with carbon emissions from increased electricity production.
EC = Conventional vehicle energy consumption (TJ/km) Calorific Value = Calorific value per type of fuel used by vehicles (TJ/L) Fuel Consumption = Vehicles fuel consumption (km/L) E= Carbon Emission per year (ton CO2/year) Distance = Distance covered by official vehicles per year (km/year)

Figure 1
Figure 1 Efficiency of official substitution with EVs.Each scenario reduction percentage are compared to the number of vehicles unit being replaced in Serang Regency.

Figure 2
Figure 2 Efficiency of official substitution with EVs.Each scenario reduction percentage are compared to the number of vehicles unit being replaced in Banten Province.

Table 1
below Serang Regency Official Vehicles Data

Table 2
Banten Province Official Vehicles Data

Table 3
Fuel Emission Factor and Calorific Value AccordingTo KLHK 2012 This calculation was done by multiplying the value of carbon emissions resulting from PLN's electricity production by the EVs energy consumption.

Table 4
Conventional Vehicle Carbon Emissions Calculation

5
EVs Carbon Emission Calculations

Table 6
Calculation of Carbon Emission Reduction of EVs Substitution

Table 2
(8)vince.Equation(8)was used to find the percentage reduction from service vehicle substitution for each scenario and the following results were obtained.Reduction Percentage from Official Vehicles Substitution to EVs in Serang Regency Tabel 9 Reduction Percentage from Official Vehicles Substitution to EVs in Banten Province