How Electric Vehicles Can Make Tajikistan Emissions-Free

ADB selected Dushanbe as one of the cities that can champion the adoption of electric vehicles. The city has about one million residents, who are served with a well-functioning public transport network. The number of cars relative to the number of city inhabitants is low. 

The city’s transport-related GHG emissions reached 330,000 total carbon dioxide (tCO₂) in 2018. Including indirect emissions, GHG emissions totaled 420,000 tCO₂in 2018. This number is expected to double to 850,000 tCO₂ by 2030. 

The road transport sector of Dushanbe is responsible for around 3% of Tajikistan’s total GHG emissions. Passenger cars are the leading source of GHG emissions, followed by buses. Commercial vehicles (i.e., taxis, buses, trucks), although only representing 18% of all vehicles, are responsible for more than 50% of GHG emissions.

Figure 1: Share of GHG Emissions Road Transport in Dushanbe, 2018 (WTW)

WTW = Well-to-wheel analysis

Source: Grutter Consulting.

Passenger cars in the city are gasoline-powered while buses are diesel-powered, both having high particles and oxides of nitrogen emission that can be avoided with electric vehicles. A bus however has the same GHG emission impact as 22 passenger cars. Using a taxi instead of a private car reduces emissions by four times. This is because of the higher annual mileage and higher fuel consumption of buses and taxis compared to cars. 

Table 1: Motor Vehicles in Dushanbe, 2018

Source: Municipality of Dushanbe; annual mileage estimated based on average international figures except for buses.

In Dushanbe, four state-owned enterprises operate about 650 buses, including 109 trolleybuses. Apart from the trolleybuses, all units are diesel-powered with new units complying with emission standard Euro V. Four hybrid-electric trolleybuses were tested for 6 months and yielded positive results. The city intends to purchase more hybrids and expand its trolleybus network.

Commercial potential of electric vehicles

Electric vehicles have a higher investment cost and might require replacement of costly batteries during a vehicle’s lifespan. However, battery costs are decreasing by less than 10% per annum while battery quality is improving in terms of degradation rates and power storage. These factors reduce the difference in capital expenditure between electric vehicles and fossil fuel vehicles.

In terms of operational costs, electric vehicles have lower energy costs because of energy efficiency and lower maintenance costs. They also have a longer lifespan with less vibration and moving parts. However, the actual cost will depend on the vehicle category and the number of electric vehicles operated. Small numbers of vehicles result in higher maintenance and vehicle standstill costs incurred from long waiting times for spare parts, lack of qualified mechanics, and the lack of a secondary spare parts market. The total cost of ownership comparison below for different types of commercial vehicles includes only the capital expenditure (including battery replacement based on same-standard lifetime or mileage per vehicle) and energy costs.

Figure 2: Total Cost of Ownership per Vehicle km (CAPEX plus Energy) for Dushanbe

CAPEX = capital expenditure

Source: Grütter Consulting.

A comparison of total cost of ownership of e-buses against diesel Euro V buses as recently purchased by the city shows that hybrid trolleybuses and battery e-buses with fast-charging technology have lower total costs than diesel units (slow-charging battery e-buses have slightly higher costs). Hybrid trolleybuses are a suitable option for some routes and battery e-buses for other routes. 

Co2 Reduction by Electric Buses in Dushanbe

EVs can reduce GHG emissions compared to conventional vehicles by nearly 100% due to the very low carbon grid factor of Tajikistan. They are an effective measure to reduce GHG emissions of the transport sector, whilst also reducing air pollution and noise and the dependency on fossil fuel imports. The following figure shows the GHG potential of electric buses and taxis with the carbon grid factor of Tajikistan.

Figure 3: GHG Impact Standard Urban Bus in Dushanbe (gCO2e/km WTW)

Source: Grutter Consulting

Assuming that electric vehicles in all vehicle categories, including passenger cars, make up 30% of newly purchased vehicles by 2030, GHG emissions could be reduced by up to around 210,000 tCO_2e, 25% less than the transport emission projection for Dushanbe in the business-as-usual scenario.

Table 2: Modelling Targets for the Share of Electric Vehicles in New Vehicle Purchases in Dushanbe

Source: Grutter Consulting.

Figure 4: GHG Emissions Transport Sector Dushanbe under a Business as Usual and with EV Scenario

Source: Grutter Consulting

With the slow buildup of the electric vehicle fleet, the study expects the impact on electricity consumption to be small. Even by 2030, the total electricity consumption from electric vehicles will be only 1% of the electricity production and only around 10% of electricity exports in 2016. This means that electric vehicles could be accommodated without expanding electricity production but by just reducing electricity exports.

It is proposed that Dushanbe focus initially on the replacement of fossil fuel buses with electric units. The second phase can then focus on electric taxis.These are the areas where solutions are relatively simple technically and electric vehicles are cost-effective. 

E-buses result in a significant reduction of emissions. Replacing 200 23-meter diesel buses with e-buses results in GHG emission savings of 200,000 tCO₂over the lifetime of the buses as well as reduces noise pollution. This creates a good opportunity for attracting climate finance.

E-buses have a higher capital expenditure than diesel buses. There are also risks in adopting a new technology. The investment in e-buses would require a different financial structure. The environmental advantages of e-buses could be used to access climate finance with partial grant and partial concessional funding. This would result in a low-cost financial structure and lower operational costs for the city. 

The study recommends that the city make an in-depth assessment of e-bus technology options for different bus routes, taking into account the public transport operating characteristics, traffic conditions,and grid system of Dushanbe.  

Financially, e-buses are the electric vehicle alternative with the lowest additional costs and lowest technological complexity. In addition, no large charging infrastructure needs to be established. 

For large-scale public transport operators, subsidies of buses and especially the charging infrastructure are essential. Also, targets should be set for the share of e-buses. However, such targets, if not matched with subsidies, can result in higher deficits of transport operators or an increase in tariffs.

Grutter Consulting. 2018. E-Mobility Options for Developing Member Countries of ADB

United States Environmental Protection Agency. Criteria Air Pollutants. https://www.epa.gov/criteria-air-pollutants