Unveiling the Spatial Distribution of Heat Demand in North-West-Europe Compiled with National Heat Consumption Data

Round 1

Reviewer 1 Report

The paper is generally well written, and it does present some novelty to the subject, also presenting some ideas of solutions, that can be used in practice. It could of interest of readers of the journal.

However, I propose to consider the following points before publication:

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Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments

The authors have examined ‘‘Unveiling the spatial distribution of heat demand in North-West-Europe compiled with national heat consumption data’’ in this paper.  Authors should revise the paper by following suggestions.

1: The abstract section should be revised with main objective, novelty and conclusion.

2: What is the main purpose of current study?

3: What is the major area of application of this work?

4: What problem was studied and why is it impact? What is the novelty of the work and where does it go to beyond previous effects in the literature.

5: What are the main consequences of present model?

6: Revise the abstract section to accurately present not only the aim of the study and methodology.

7: Need more discussion about the results? In the results section, the author needs to analyze the finding by giving reasons for each fact. Please explain every point?

8: What are convergence criteria of present model?

9: The Introduction should make a compelling case for why the study is useful along with a clear statement of its novelty or originality by providing relevant information and providing answers to basic questions such as: 

a.     What is already known in the open literature?

b.     What is missing (i.e., research gaps)?

c.     What needs to be done, why and how?

Major revision.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

A heat demand map with spatial resolution of 100*100m² for the residential and commercial sectors in the Interreg North-West-Europe region is reported in this paper, along with an open-source Python package PyHeatDemand. Methodologies are proposed to project data from different categories of sources into 100*100m² polygons. Based on the map, the spatial distribution of heat demand in North-West-Europe region is analyzed. This work provides a visual and quantitative understanding of heat demand, and is useful for planning of heating systems in different spatial scales. Since the methodologies and results are clearly presented, I suggest that the paper can be accepted.

Some minor problems:

1) Abbreviation CRS is used in line 164 before introduced in line 218. It is suggested to check other abbreviations.

2) It is suggested to add values to the colorbar in Figure 14.

Author Response

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Author Response File: Author Response.docx

Reviewer 4 Report

This paper is well written. The introduction gives a good overview of the field, with a good selection of references. The methodology is clearly explained, and the results are worth being published. As the authors mention, the heat demand maps can be useful for policymakers. I also appreciate the discussion section, where the authors also mention the limits of the work.

Nevertheless, I have pointed out some minor points which would increase the quality of the work. 

In the paragraph starting in line 55 page 2, please give more information of the origin of the heating demands. I assume that for commercial regions the intensity is higher since the heating demand is not only for space and sanitary hot water as in residential areas, but can also include process heat requirements.

Page 7, line 190. The fraction of gas used for space heating SH and hot water heating HW is set to 72% and 23%, respectively. Can you provide any explanation for the remaining 5%?

If the aim is to calculate the total heat demand, then the term SH ∗ HW is not clear, I would suggest (SH+HW) in case you want to account for both heat demands in total. Furthermore, where is the mean efficiency of these gas fired systems included (e.g. 90%)? I would suggest multiplying this equation by 90%.

Page 10, lines 253-254: "HD values  below 15 MWh/ha are not displayed in the maps, due to calculation inaccuracies and low significance for investment projects". If possible, the authors could provide which % of the assessed area this implies, and which % of the total heat demand (a very low % I assume, and probably limited to rural areas).

Page 12, first paragraph: if possible, relate differences in the share of residential or commercial demands with social/demographic/industrial differences between countries. Same for page 21, lines 501-502 when you mention “In Germany, the share of the commercial sector is noticeably higher (43.9%) and the residential heat demand is accordingly lower (56.1%).” You could potentially explain this, as done in page 22, lines 549-553, for Luxembourg.

The work is well supported by the Appendix including supplementary results.

The discussion provides an objetive, critical analysis on the limits of the scope of the analysis (e.g. relation with climatic aspects, limiting factors in the age of the underlying data).

The article is in general very well written and explained. However, the following minor details of the English grammar/expression could be corrected.

Page 1 Abstract. Please add “The” results reveal… Another recommendation is to avoid starting sentences with “It" as in "It is assumed…”

Another example is in “…it is to be expected” line 40 page 2.

Please also rephrase “so that in particular” in line 42 page 2.

Line 94 of page3: please avoid starting with “It does not aim” and “It is also possible” in line 122.

Please correct Page 4 line 116 (“of for“).

In general I recommend to replace the use of “about” with“around” (which is more formal) and avoid starting with “The” in titles of figures or tables.

Label of Figure 7 page 11: avoid “so it is not shown in the”

Page 12, line 308: "It turns out that only 16.1%..."

Page 21, line 526: “It is more likely..."

Page 23, line 618 “It is, therefore,”

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Accept

Not required.