Different Charging Strategies for Electric Vehicle Fleets in Urban Freight Transport

Round 1

Reviewer 1 Report

I stongly believe that the paper has sufficent contribution to justify publishing the article. However, I believe some minor comments needs to be considered before publishing. I believe the abstract is very well, and should guide the rest of the document (that sometimes does not occur). In some section of the article, it seems that the authors deviate to explain the performance of electric vehicles, the barriers for the introduction, the penetration of this technology, etc, which deviate from the aim of the article.

Follow some minor comments:

1) A transition between the first and second paragraph is needed, since Netherlands is not introduced before. May be reodering the paragraph could solve this problem. 

2) Line 47 suggests "with it's ultra-low"

3) Line 48, suggest "on vehicles and emissions".

4) Line 84. Section 6 is not mentioned

5) LIne 115. Rewrite sentence, could be intrepreted as 91% by a unique company

6) Line 118 I don't find relevant to include a not extensive list of barriers, that are mostly operative, and that don't include the ones relevants for the paper. This was my main concerns, that makes the reader deviate from the main contribution.

7) Line 138 - "our" street is not representative of the world.

8) Line 157 . May be a previous definition of LV, Heavy vehicles, is needed.

9) May be section 2.1 and 2.2 could be joined and shortened.

10) Line 238 - I suggest include load capacity of vehicles. This information is mentioned later in the paper.

11) Line 252 . Typo "can"

12) Table 5 could be splitted in two. For example, 130 km per day is the same for all scenarios.

13) An analysis of sensibility with the km as a variable could be also interesting

14) Line 396, typo: "difference" instead of "different"

15) Line 545 typo: "term" instead of "team"

16) Line 596, recommend rewritting the sentence.

17) Section 4.1 should be evaluated if necesary or if could be presented as a description of the case study. Moreover, although mentioned the reference, some numbers or figures of the indicators mentioned in table 4 could be included in this section. In other word, try to focus the paper, literature review, results, findings. 

Author Response

We would like to thank the reviewer for the valuable comments. We tried to address all comments and suggestions in the following way (and as can be found in the attached document in track changes) :

1) A transition between the first and second paragraph is needed, since Netherlands is not introduced before. May be reodering the paragraph could solve this problem.  

We indeed reorded the paragraph; the Netherlands follows now more logical as one of the areas where (ultra) low emission zones or even zero emission zones are established.

2) Line 47 suggests "with it's ultra-low"

We corrected this.

3) Line 48, suggest "on vehicles and emissions".

We corrected this

4) Line 84. Section 6 is not mentioned

Section 6 is now included

5) LIne 115. Rewrite sentence, could be intrepreted as 91% by a unique company

Line has been rewritten.

6) Line 118 I don't find relevant to include a not extensive list of barriers, that are mostly operative, and that don't include the ones relevants for the paper. This was my main concerns, that makes the reader deviate from the main contribution.

The list of barriers is moved to section 3 and made shorter. It is now presented as challenges that the operators phase, and that were at the base of the developed case study. Next, section 2.1 and section 2.2 are joined and made shorter, as the reviewer suggests.

7) Line 138 - "our" street is not representative of the world.

Very true, corrected.

8) Line 157 . May be a previous definition of LV, Heavy vehicles, is needed.

We added a better explanation on light vehicles and heavy vehicles.

9) May be section 2.1 and 2.2 could be joined and shortened.

See comment 6; we did as the reviewer suggested to improve readability and reduce deviation

10) Line 238 - I suggest include load capacity of vehicles. This information is mentioned later in the paper.

We added gross vehicle weight as to better explain the size of the vehicles (and the corresponding load capacity)

11) Line 252 . Typo "can"

Corrected

12) Table 5 could be splitted in two. For example, 130 km per day is the same for all scenarios.

We improved table 5, so that it is better readable: the mission profile differs per vehicle type (as this follows from the case study, as direct result of the difference in battery size and operations it is used for)

13) An analysis of sensibility with the km as a variable could be also interesting

An analysis of the sensibility with kms is indeed interesting; we decided not to include it in the paper though, as the results turned out to be quite straightforward and were already part of earlier, see for example FREVUE deliverable 3.2 Economics of EVs for City Logistics -Report at https://frevue.eu/wp-content/uploads/2017/09/FREVUE_D3.2-Final-Report_2.0_submitted.pdf

14) Line 396, typo: "difference" instead of "different"

Corrected.

15) Line 545 typo: "term" instead of "team"

Corrected.

16) Line 596, recommend rewritting the sentence.

Line has been rewritten

17) Section 4.1 should be evaluated if necesary or if could be presented as a description of the case study. Moreover, although mentioned the reference, some numbers or figures of the indicators mentioned in table 4 could be included in this section. In other word, try to focus the paper, literature review, results, findings.

We included more information on the monitoring results in section 4 (that were in the original paper not presented, as we mainly discussed the learnings from the time the electric freight vehicles operated). For more detailed results of the operations that were monitored we refer to the monitoring report that provides a full reporting on all indicators mentioned in table 4.

Author Response File: Author Response.pdf

Reviewer 2 Report

Summary:

As fleet operators electrify their fleets, devising a viable planning strategy remains a challenge for them. This study assesses the trade-off between a large battery pack (with less reliance on public charging) and a smaller battery pack (with more reliance on public charging) with regard to costs constraints.

The research encompassed a case-study in the Rotterdam area in which the charging operations of two transport operators were analyzed. A total of 39 vehicles (from 3 categories: small vans, large vans and small trucks) were analyzed. A qualitative assessment (interviews and process reviews) and a quantitative assessment (TCO analysis) were conducted.

For the small vans category, small electric vans with a large battery pack are already more cost-effective than conventional vehicles; for small vans with smaller batteries, the TCO is higher than that of conventional vehicles. For the large vans category, electric vans with both a large battery pack and a small battery pack have a higher TCO than conventional vehicles; this difference is relatively small for large vans with a large battery pack. For small trucks, electrification is the most uneconomical among the three vehicle categories studied. For small trucks, the electric variants have a much higher TCO than conventional trucks; this is because of high battery prices of electric trucks.

The study then analyses the impact of falling battery prices and lessened daily transport kilometers on the TCO. Under these circumstances, the study concludes that the TCO for the electric versions of all the three vehicle classes studied (small vans, large vans and small trucks) will come down; this will hold true for electric vehicles with both large and small batteries, making these vehicles competitive with their conventional counterparts.

Strong Points:

• The factual information in the paper was in sync with leading electric vehicle publications, like the International Energy Agency’s Global EV Outlook. Factual information like the high power requirements for electric trucks, low OEM integration of large electric trucks, etc.
• The data collection for the case-study was rigorous; it encompassed both qualitative and quantitative data collection.
• The literature review was very detailed and was a sufficient pre-requisite for the methodology and results sections.
• The parameters that went into the TCO were diverse ranging from driver cost to energy cost.
• It was good that the paper had the TCO sensitivity analyses that took into account the following facts: Battery prices will fall in the future. On many days, the vehicle demand is less than the range.

Weak Points:

• There were many grammatical errors and spelling mistakes in the paper (see highlighted examples in the attached PDF of the manuscript).
• The graphs provided in the results section of the paper were probably inadequate. For instance, a good idea would have been to add the graphs for large vans and small trucks right next to the figure for small vans in the TCO section.
• In the sensitivity analysis on mass production of electric freight vehicles, the battery price is lowered to 166 €/kWh. It would be good to elaborate what the source of this specific number was – literature reviews, mathematical modelling or just random number usage.

Comments for author File: Comments.pdf

Author Response

We would like to thank the reviewer for the valuable comments, the strong and the weak points. We tried to address all suggestions that follow from the weak points in a sufficient way (and as can be found in the attached document in track changes).

• There were many grammatical errors and spelling mistakes in the paper (see highlighted examples in the attached PDF of the manuscript).

We found indeed too many grammatical errors and spelling mistakes in the paper. We improved all highlighted examples and corrected the rest of the paper for errors and mistakes as good as possible.

• The graphs provided in the results section of the paper were probably inadequate. For instance, a good idea would have been to add the graphs for large vans and small trucks right next to the figure for small vans in the TCO section.

We included the graphs for the large vans and small trucks in figure 2.

• In the sensitivity analysis on mass production of electric freight vehicles, the battery price is lowered to 166 €/kWh. It would be good to elaborate what the source of this specific number was – literature reviews, mathematical modelling or just random number usage.

We explained how we came to the 166EUR/kWh in the paper and added the source.

Author Response File: Author Response.pdf