Life Cycle Cost Assessment of Electric, Hybrid, and Conventional Vehicles in Bangladesh: A Comparative Analysis

Round 1

Reviewer 1 Report

This paper provides a life cycle cost assessment of electric, hybrid and internal combustion vehicles in the Bangladesh market. The paper is very interesting and publication can be recommended if some issues are addressed.

The paper is exclusively focused on Bangladesh, although there is a literature survey which provides a more global perspective. This focus on Bangladesh should be made clear in the title and the abstract so that interested readers do not overlook this aspect of the paper.

Abstract: LCC should be defined or the abbreviation should not be used in the abstract.

L152. Define SWOT-AHP.

Figure 1 is not referenced in the text. Also, the figure caption should read “BZ3”.

L 206, 243, 253, 274. A new paragraph (marked with indentation) should not be started in these places as this is a continuation of the text.

It would be easier for the general reader to indicate all prices in dollars.

Important. Some of the assumptions for maintenance costs may be challenged

L268-269. “Battery replacement significantly contributes to the overall maintenance cost for electric vehicles, as will be demonstrated.” Most electric cars will not have their battery changed after 10 years for a full life cycle of 12 years. This makes no sense. “According to current industry expectations, EV batteries are projected to last between 100,000 and 200,000 miles, or about 15 to 20 years. However, even when EV batteries do age, their large initial capacity combined with minor losses in battery capacity means the aging is nearly imperceptible to drivers”, quoted from How long do electric car batteries last? [May 2023] | EVBox

These additional costs included by the authors for battery replacement in EVs substantially increases the projected LCC of EVs.

L383-384. The cost of batteries may be decreasing faster than anticipated. CATL now offer batteries at $56/kWh. World's largest EV battery maker set to cut costs in half by mid 2024 (thedriven.io)

L397-399. “Hybrid cars generally have fewer mechanical parts, which means there is less potential for things go wrong and break down.” Are there any references to support this statement? It seems highly surprising considering hybrid cars are probably the most technologically complicated type of drivetrain ever to be developed consisting of an internal combustion engine and battery which should operate in sync. The drivetrain is much more complicated than a simple battery as found in EVs. Hence, I cannot agree with the maintenance costs projected in Table 4.

L389. “Figure 3” should read “Figure 5”.

L572. “Among three types of vehicles, ICEVs are the most expensive and HEVs are the cheapest while EVs lie in between them according to Life cycle cost (LCC). LCC of Toyota BZ3 (EV) has been calculated to be USD 45,859, more expensive than Toyota Aqua (HEV) and Toyota Prius (HEV), but cheaper than Toyota Axio (ICEV) and Toyota Allion (ICEV).” Please quote costs of all vehicles as this sentence may be easily misread.

Author Response

Response to Reviewer # 1 Comments

Summary

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

Comment 1: The paper is exclusively focused on Bangladesh, although there is a literature survey which provides a more global perspective. This focus on Bangladesh should be made clear in the title and the abstract so that interested readers do not overlook this aspect of the paper.

Response 1: Thank you for pointing this out. We agree with this comment. Therefore, we have changed the title from “Life Cycle Cost Assessment of Electric, Hybrid and Conventional Vehicles: A Comparative Analysis” to “Life Cycle Cost Assessment of Electric, Hybrid and Conventional Vehicles in Bangladesh: A Comparative Analysis”.

In abstract, line 19-22, “Our calculation on most popular Toyota cars shows that LCC of Toyota BZ3 (EV) (about 45,859USD) is more expensive than Toyota Aqua (HEV) and Toyota Prius (HEV), but cheaper than Toyota Axio (ICEV) and Toyota Allion (ICEV)” has been changed as “Our calculation on the most popular private car brand in Bangladesh, Toyota shows that the life cycle cost (LCC) of Toyota BZ3 (EV) USD43,409 is more expensive than Toyota Aqua (HEV) and Toyota Prius (HEV), but cheaper than Toyota Axio (ICEV) and Toyota Allion (ICEV)”.(P1, L19-22)

Comment 2: L152. Define SWOT-AHP.

Response 2: A sentence is added to define SWOT-AHP as “Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis together with Analytic Hierarchy Process (AHP), a multicriteria decision making technique is called SWOT-AHP” (P5, L-155-157).

Comment 3: Figure 1 is not referenced in the text. Also, the figure caption should read “BZ3”.

Response 3: Figure 1 has been referenced in the text (P6, L-181). The figure caption is added.

Comment 4: L 206, 243, 253, 274. A new paragraph (marked with indentation) should not be started in these places as this is a continuation of the text.

Response 4: The new paragraphs in L 206, 243, 253, and 274 have been removed.

Comment 5: It would be easier for the general reader to indicate all prices in dollars.

Response 5: All prices have been indicated to USD beside BDT (P13,14, Table-3, and wherever applicable).

Comment 6: Important. Some of the assumptions for maintenance costs may be challenged

L268-269. “Battery replacement significantly contributes to the overall maintenance cost for electric vehicles, as will be demonstrated.” Most electric cars will not have their battery changed after 10 years for a full life cycle of 12 years. This makes no sense. “According to current industry expectations, EV batteries are projected to last between 100,000 and 200,000 miles, or about 15 to 20 years. However, even when EV batteries do age, their large initial capacity combined with minor losses in battery capacity means the aging is nearly imperceptible to drivers”, quoted from How long do electric car batteries last? [May 2023] | EVBox

These additional costs included by the authors for battery replacement in EVs substantially increases the projected LCC of EVs.

Response 6: Thank you for pointing this out. We agree with this comment. Therefore, we changed the text as “According to current industry expectations, EV batteries are projected to last between 100,000 and 200,000 miles, or about 15 to 20 years. EVs are estimated to lose an average of 2.3 percent of their battery capacity per year. Even after driving 12 years, it will have more than 70% capacity to store power and battery replacement for EVs will not be applicable. On the other hand, HEVs and ICEVs will incur battery replacement cost.” (L279-283, P10-11). Accordingly, the LCC has been recalculated.

Comment 7: L383-384. The cost of batteries may be decreasing faster than anticipated. CATL now offer batteries at $56/kWh. World's largest EV battery maker set to cut costs in half by mid 2024 (thedriven.io)

Response 7: We used previous cost structure of batteries, which stated $98.5 per kWh (https://www.visualcapitalist.com). However, as per your suggestion with latest information, we have changed the cost of battery and changed the text as “Contemporary Amperex Technology Co., Limited (CATL), world’s largest EV battery maker now offers batteries at $56/kWh.  For the Toyota BZ3's battery (71.4 kWh), this translates to a cost of around $4000 (BDT 440,000)”. (P-16, L394-397).

Comment 8: L397-399. “Hybrid cars generally have fewer mechanical parts, which means there is less potential for things go wrong and break down.” Are there any references to support this statement? It seems highly surprising considering hybrid cars are probably the most technologically complicated type of drivetrain ever to be developed consisting of an internal combustion engine and battery which should operate in sync. The drivetrain is much more complicated than a simple battery as found in EVs. Hence, I cannot agree with the maintenance costs projected in Table 4.

Response 8: “Hybrid cars generally have fewer mechanical parts, which means there is less potential for things go wrong and break down” (https://mitsubishi-bd.com/the-advantages-of-owning-a-hybrid-car-in-bangladesh). However, the statement may not be correct, because some statements are made by business people for commercial purpose. But we must use the most authentic information for analysis. Your argument seems to be more logical. Therefore, we have changed the text as “Hybrids have both electric and internal combustion engines, meaning that they have all the maintenance costs of both types of cars. The owner will still need regular oil changes and replace parts like spark plugs, batteries and brake pads on roughly the same maintenance schedule. However, because there are two engines in a hybrid, some of the parts are hard to get to when replacing them, which can lead to higher labor costs. A study shows that maintenance cost of HEV is 58% higher than that of an ICEV” (P-16, L409-414).  Regular maintenance cost of HEV has been changed from BDT 15,000 to BDT 28,000 (P-16, L419-420).  Accordingly, LCC has been recalculated.

Comment 9: L389. “Figure 3” should read “Figure 5”.

Response 9: “Figure 5” has been corrected instead of Figure 3 (P-21, L511-512). 

Comment 10: L572. “Among three types of vehicles, ICEVs are the most expensive and HEVs are the cheapest while EVs lie in between them according to Life cycle cost (LCC). LCC of Toyota BZ3 (EV) has been calculated to be USD 45,859, more expensive than Toyota Aqua (HEV) and Toyota Prius (HEV), but cheaper than Toyota Axio (ICEV) and Toyota Allion (ICEV).” Please quote costs of all vehicles as this sentence may be easily misread.

Response 10: According to your suggestion this part has been changed as “Among three types of vehicles, ICEVs are the most expensive and HEVs are the cheapest while EVs lie in between them according to Life cycle cost (LCC). LCC of Toyota BZ3 (EV) has been calculated to be USD 43,409, more expensive than Toyota Aqua (HEV) with a cost of USD35,789 and Toyota Prius (HEV) with a cost of USD41,569. On the other hand, Toyota BZ3 (EV) is cheaper than Toyota Axio (ICEV) with a cost of USD51,907 and Toyota Allion (ICEV) with a cost of USD56,932. (P27, L601-605)

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors

The article is interesting, but in my opinion it contains some errors and needs to be corrected before being accepted for publication.

In order to improve the quality of the article, I suggest including the following comments:

1)      In their analysis, the authors assumed a very low value for the energy consumption of an electric car (BZ3). The value shown in Table 1, i.e. 8.7 km/kWh, which corresponds to an average energy consumption rate of about 11.5 kWh/100 km. However, the website provided in the body of the manuscript by the authors (https://motowheeler.com/bd/electric-cars/toyota-bz3-10107) contains different data than that adopted for the analysis. This is particularly true of the battery capacity (71.4 kWh) and energy consumption (related to the specified range). In the case of the data from the website cited by the authors, assuming according to the table on the aforementioned website that the range will be 252 miles (about 405.5 kilometers), the theoretical energy consumption rate is about 17.62 kWh/100 km (about 5.67 km/kWh). It should be borne in mind that this is the rate for the theoretical total battery energy consumed, and in reality Useable Capacity is lower. On what basis, then, did the authors assume the value of the energy consumption rate?

2)      The descriptions used in the tables are not precise. It is advisable, to make their improvement. For example, in Table 1 (and Table 3) - "Engine cc or hp" would be beneficial to replace with "Engine displacement (cc) or Motor power (hp)/(kW)"; similarly, the description "Car cc" (which refers to the engine), "Regular vehicle" should be corrected in Table 2, while is the description in the table "Electric vehicle" appropriate if import taxes are attributed to engine displacement? Should Hybrid vehicle be understood in its place. The text in the tables should be corrected to make it clearer to the reader.

3)      Also, the costs that the authors present in the manuscript should be presented in US dollars. The values presented partly in US dollars (USD) and partly Bangladesh Taka (BDT) make the analysis presented in the article difficult for the reader. Therefore, it would be beneficial to supplement the values presented in BDT also in USD. In addition, Table 3 includes costs specified in Tk. (fuel cost and tyre replacement), which makes the cost analysis even more difficult.

4)      In the conclusions, it would also be advisable to refer to other costs associated with waste management of used automotive (traction) batteries.

Best regards,

The article contains numerous linguistic, editorial and formal errors. For example: in the description of equation (7), the authors presented "where Di, Cgas i and Celec,i are distance traveled, cost of gasoline and electricity cost." - Cgas does not appear in the equation; erroneous reference to Tables 2 and 3 in the body of the manuscript; in the description of the axis in Figure 4 "registration fee"; erroneous reference to Figure 5 (line 489); similarly erroneous reference (or lack thereof) in the text to Figures 6, 7, 8, 9 and 10; in the equations in the manuscript, the exponent designations (i) should be corrected - the remark applies to equation (4), (8), (10), (11). In my opinion, proofreading is advisable before allowing it to be published.

Author Response

Response to Reviewer #2 Comments

Summary

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

Comment 1: In their analysis, the authors assumed a very low value for the energy consumption of an electric car (BZ3). The value shown in Table 1, i.e. 8.7 km/kWh, which corresponds to an average energy consumption rate of about 11.5 kWh/100 km. However, the website provided in the body of the manuscript by the authors (https://motowheeler.com/bd/electric-cars/toyota-bz3-10107) contains different data than that adopted for the analysis. This is particularly true of the battery capacity (71.4 kWh) and energy consumption (related to the specified range). In the case of the data from the website cited by the authors, assuming according to the table on the aforementioned website that the range will be 252 miles (about 405.5 kilometers), the theoretical energy consumption rate is about 17.62 kWh/100 km (about 5.67 km/kWh). It should be borne in mind that this is the rate for the theoretical total battery energy consumed, and in reality, Useable Capacity is lower. On what basis, then, did the authors assume the value of the energy consumption rate?

Response 1: Thank you for pointing this out. We completely agree with this comment. We took the battery capacity to be 49.96 kWh by mistake, so the fuel consumption figure was 8.7 km/kWh, which was incorrect. Therefore, we have changed the text as “With a full charge, the Toyota BZ3 (with battery capacity 71.4 kWh) can run about 252 miles (about 405.5 kilometers). The theoretical energy consumption rate is about 17.62 kWh/100 km or about 5.67 km/kWh. It should be borne in mind that this is the rate for the theoretical total battery energy consumed, and in reality, useable capacity is lower.” (P15, 382-385)

In addition, the latest electricity bill rate has been adjusted with our calculation which has been effective from March, 2024 as “Recently Ministry of Energy, Power and Mineral resources has published a gazette, where a flat rate has been set for EV charging station, effective from March 2024. The rate is BDT 9.62/kWh plus BDT 90 demand rate/charge (Bangladesh Gazette, MOPEMR, 2024). Assuming a Toyota BZ3, which requires 3132 kWh to drive 14,740 km per year at an 83% charging efficiency. Moreover, 44 times the demand charge will be paid per year. Electricity bill will be total BDT 34,090. Additional 20% payment will be charged (VAT + surcharge) by the government. Thus, yearly EV charging cost of Tk. 40,908 was assumed, resulting in a cost of BDT2.78 or USD 0.0253 per kilometer.” (P15, L385-393). Consequently, the LCC has been recalculated.   

Comment 2: The descriptions used in the tables are not precise. It is advisable, to make their improvement. For example, in Table 1 (and Table 3) - "Engine cc or hp" would be beneficial to replace with "Engine displacement (cc) or Motor power (hp)/(kW)"; similarly, the description "Car cc" (which refers to the engine), "Regular vehicle" should be corrected in Table 2, while is the description in the table "Electric vehicle" appropriate if import taxes are attributed to engine displacement? Should Hybrid vehicle be understood in its place. The text in the tables should be corrected to make it clearer to the reader.

Response 2: "Engine cc or hp" has been replaced by “Engine displacement (cc) or Motor power (hp)/(kW)” in table 1 (P-7) and table 3 (P-13). "Car cc" is replaced by “Engine displacement (cc)” and "Regular vehicle" is replaced by “ICEV and HEV” in table 2 (P-9). Bangladesh tax authority has imposed these tax rates, and it did not mention anything about HEV. We can assume that in the place of regular vehicles both ICEV and HEV may be considered (P9, Table-2).

Comment 3: Also, the costs that the authors present in the manuscript should be presented in US dollars. The values presented partly in US dollars (USD) and partly Bangladesh Taka (BDT) make the analysis presented in the article difficult for the reader. Therefore, it would be beneficial to supplement the values presented in BDT also in USD. In addition, Table 3 includes costs specified in Tk. (fuel cost and tyre replacement), which makes the cost analysis even more difficult.

Response 3: I agree to your comment. Accordingly, all monetary figures have been mentioned in both BDT and USD. (P13,14, Table-3, and wherever applicable).

Comment 4: In the conclusions, it would also be advisable to refer to other costs associated with waste management of used automotive (traction) batteries.

Response 4: To address other costs associated with waste management of used automotive batteries, we have added this part in conclusion “At present about 1.5 million battery driven three-wheeler easy-bikes are running on the roads of Bangladesh, which produces huge amount of electronic waste and this amount is expected to increase after the adoption of EVs. Unfortunately, the majority of the country’s LIB waste is currently being disposed of in landfills, leading to adverse consequences for both the environment and public health. However, this waste contains valuable resources such as cobalt, lithium, base metals, graphite, and others, which have the potential to be locally recovered and utilized in the production of new products. In light of the pressing issue of climate change, it is imperative to adopt interdisciplinary solutions to effectively address the management of end-of-life lithium-ion batteries (LIBs) used in Electric Vehicles (EVs) and prevent potential waste problems in the future. Several research studies have highlighted that the recycling costs of $9/kWh are relatively minor compared to the manufacturing costs of $56/ kWh. Additionally, recycling LIBs can significantly reduce the normalized and weighted environmental impact of these cells by an impressive rate of 75%.” (P-28, L633-646)

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

In order to improve the quality of the article, I suggest including minor comments:

1)      Lines 70 and 71: "KM" should be corrected to lowercase "km/liter". "KM" may be misunderstood as "Horsepower".

2)      In Table 1, in place of "Fuel Efficiency," a more favorable description would be: "Energy of Fuel Efficiency".

3)      In Table 2, the classification of charges for electric cars according to engine capacity is not fully understood. In the body, the authors cite the energy 1 kWh equivalent for electric cars assumed in Bangladesh (BRTA) as the equivalent of 20 cubic centimeters of engine displacement. It would therefore be beneficial to supplement this equivalent in the table (eg. Engine displacement (cc) / EV Battery capacity (kWh) - 1500 / 75 ).

4)      In Table 3, replace the description "Fuel consumption" with "Energy/Fuel efficiency".

5)      In the body of the article, insert spaces between the currency designation and the values (for example in line 17: USD 43,409). In addition, standardize the currency designation in the content (the authors use USD, US$ and $).

Best regards,

Comments can be found in the review content.

Author Response

Response to Review Round 2

1. Summary

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/ in track changes in the re-submitted files.

2. Quality of English Language

( ) I am not qualified to assess the quality of English in this paper
( ) English very difficult to understand/incomprehensible
( ) Extensive editing of English language required
( ) Moderate editing of English language required
(x) Minor editing of English language required
( ) English language fine. No issues detected

Response:  Minor editing of English language has been done as per reviewer’s suggestions.

3. Comments and Suggestions for Authors

Comment 1.      Lines 70 and 71: "KM" should be corrected to lowercase "km/liter". "KM" may be misunderstood as "Horsepower".

Response 1. KM has been corrected to lowercase km/liter. (Page 3, Line 74).

Comment 2.      In Table 1, in place of "Fuel Efficiency," a more favorable description would be: "Energy of Fuel Efficiency".

Response 2.  The term "Fuel Efficiency," has been replaced with "Energy of Fuel Efficiency". (Page 7, Table 1)

Comment 3. In Table 2, the classification of charges for electric cars according to engine capacity is not fully understood. In the body, the authors cite the energy 1 kWh equivalent for electric cars assumed in Bangladesh (BRTA) as the equivalent of 20 cubic centimeters of engine displacement. It would therefore be beneficial to supplement this equivalent in the table (eg. Engine displacement (cc) / EV Battery capacity (kWh) - 1500 / 75).

Response 3. Thank you for pointing out this important issue. We have changed the column head as “Engine displacement (cc) / EV Battery capacity (kWh).” Accordingly, in each row, we have added the equivalent EV battery capacity. (Page 9, Table 2)

Comment 4. In Table 3, replace the description "Fuel consumption" with "Energy/Fuel efficiency".

Response 4. "Fuel consumption" is replaced with "Energy/Fuel efficiency" in Table 3. (Page 14)

Comment 5.      In the body of the article, insert spaces between the currency designation and the values (for example in line 17: USD 43,409). In addition, standardize the currency designation in the content (the authors use USD, US$ and $).

Response 5. Spaces have been inserted between currency designation and the values (Page 1, Line 21; Page 16, Line 398, 399, 409, 420; Page 17, Line 429, 430; Page 18, Line 457; Page 20, Line 496; Page 27, Line 604, 605, 606, and 610)

International standardized currency code for US Dollar, USD has been used everywhere in the content instead of US$ and $. (Page 16, Line 396, 397, 417, 418, 424; Page 17, Line 427, 428, 430; Page 26, Line 573, 574, and 577).

Thank you.