A Comparison of Widespread Flexible Residential Electric Heating and Energy Efficiency in a Future Nordic Power System
Round 1
Reviewer 1 Report
This article deal with case studies on the potential benefits of power-to-heat (P2H) flexibility and energy efficiency improvements in a hypothetical future Finnish scenario in the year 2030, by using a stochastic integrated Unit Commitement and Demand Side Management approach.
The overall impression of the manuscript is fairly good. However, there are some aspects that should be carely taken into account by the Authors in order to accept the article for publication.
In par 2.3, the Authors mention the Backbone method: they provided a link, but a short description should be inserted in to the text, explaining better the use of formula (1) and (2). Please specify the meaning and the measuring units of the variables included in the formulas.
The nomenclature paragraph should be moved and located at the beginning of the article. Some variables are not readable because they are one over the other. The Authors should rewrite paragraphs 3 and 4 because there are too many number about savings (expressed in EUR) that make it very difficult to read.
The literature review should be extended, since there are several articles on this subject.
As a general remark, there are several citations to technical reports, and mostly are in Finnish! the Authors should avoid citing such material, because it requires that the Reader has a knowledge of Finnish. Please limit the citation to Finnish paper to not more than 1 or 2 papers, and substitute those paper with similar papers written in English.
I wish to suggest the Authors to add one relevant (and very recent) article about demand side managements, i.e.:
Tronchin, L., Manfren, M., Nastasi, B. , Energy efficiency, demand side management and energy storage technologies – A critical analysis of possible paths of integration in the built environment, Renewable and Sustainable Energy Reviews 95, pp. 341-353, 2018
Author Response
The corresponding changes in the manuscript are highlighted in red. Note that some of the comments might overlap with the other reviewers, and could be highlighted using a different color.
"In par 2.3, the Authors mention the Backbone method: they provided a
link, but a short description should be inserted in to the text,
explaining better the use of formula (1) and (2)."
Added a brief description of the Backbone model to the beginning of the section as suggested, hopefully clarifying the overall methodology as well as the role of Equations (1) and (2).
"Please specify the meaning and the measuring units of the variables included in the formulas"
Added new descriptions of the variables and their measurement after Equations (1) and (2). Measurement units of the parameters and variables are also discussed whenever applicable.
"The nomenclature paragraph should be moved and located at the beginning of the article. Some variables are not readable because they are one over the other."
The line spacing in the nomenclature has been increased in order to increase readability. However, we are reluctant on moving the nomenclature section. Surveying a number of other articles published in Energies, the nomenclature (if included) seems to be consistently located at the end of the article. Each variable an unit are now described in the text following the equation, which should help the reader to understand the equation even without the nomenclature at the end.
"The Authors should rewrite paragraphs 3 and 4 because there are too many number about savings (expressed in EUR) that make it very difficult to read."
Sections 3.1 and 3.2 have been rewritten to be more qualitative than quantitative, reducing the amount of numbers and hopefully making the sections easier to read.
"The literature review should be extended, since there are several articles on this subject."
Included the suggested article to the introduction, as well as a few other relevant articles. However, we would wish to try and keep the literature review focused on the most relevant papers related to our work, and not branch out too much.
"As a general remark, there are several citations to technical reports, and mostly are in Finnish! the Authors should avoid citing such material, because it requires that the Reader has a knowledge of Finnish. Please limit the citation to Finnish paper to not more than 1 or 2 papers, and substitute those paper with similar papers written in English."
The cited Finnish reports are either national guidelines or results from national studies, neither of which are unfortunately available in English. They have been used as data sources as they represent the best and latest knowledge about the current state of the Finnish building stock, as well as its likely future development. Since this knowledge is primarily of interest only in Finland, these studies have not been published internationally, nor translated into English. Relying only on material published internationally would require overhauling a significant portion of the building stock data used in this work, and would degrade its quality.
Reviewer 2 Report
It is good scientific paper presenting and discussing a valuable case study. The authors are concentrated one the on important scientific and technical issue.
The original contribution is mentioned – but it is not clear – since it insufficiently related to the other approaches. In lines 31, 32, 34, 35 – there are other research and approaches mentioned, but they are grouped – not discussed. The reader does not get information what are the benefits of the approach in modelling proposed in the paper in relation to the others. This is very important part of the paper – related works – it should be developed, other approaches should be shortly discussed.
In the references to the equations in the text – use full form – for example: Equation 1 etc. Do not use abbreviations Eq. 1.
There are a lot of symbols used in the equations. They should be explained directly after the equation or reference to the nomenclature section should be mentioned in the text. For example – after the Equation 1 – some of the symbols/parameters are explained without any reference to the other nomenclature used there. Verify and correct this – throughout the entire manuscript.
All figures and tables should be cited in the main text – the best way is: the tables and figures should be placed in the main text after their first reference in the text.
There are energy costs calculated and discussed in the Section 3 and 3.1. What is the source of the mentioned energy prices? The authors should provide even short information about the source – are they related to the Finnish current prices ? It is not clear, difficult to identify – maybe reference to the appendix or bibliography…
Future works should be shortly described in the Conclusions section.
Some additional and detail remarks, comments, suggestions – see the following comments and notes in the attached PDF file with manuscript.
The subject of the paper fall within the general scope of the journal.
Presentation of the scientific problem, proposed approach and results are good.
Editorial side is good – some mistakes and gaps – see comments in the attached PDF file. Some elements should be revised according to the MDPI/Energies template and good practices.
English language is good. Technical terms and expression are correct.
Minor revision is required.
Comments for author File: 
Comments.pdf
Author Response
The corresponding changes in the manuscript are highlighted in orange. Note that some of the comments might overlap with the other reviewers, and could be highlighted using a different color.
"The original contribution is mentioned – but it is not clear – since it insufficiently related to the other approaches. In lines 31, 32, 34, 35 – there are other research and approaches mentioned, but they are grouped – not discussed. The reader does not get information what are the benefits of the approach in modelling proposed in the paper in relation to the others. This is very important part of the paper – related works – it should be developed, other approaches should be shortly discussed."
Other approaches found in literature are now briefly described, and their shortcomings are discussed in relation to the methodology in the paper.
"In the references to the equations in the text – use full form – for example: Equation 1 etc. Do not use abbreviations Eq. 1."
References to equations throughout the manuscript have been changed to conform with the conventions of the journal: e.g. "Equation (1)" instead of the previous "Eq. 1"
"There are a lot of symbols used in the equations. They should be explained directly after the equation or reference to the nomenclature section should be mentioned in the text. For example – after the Equation 1 – some of the symbols/parameters are explained without any reference to the other nomenclature used there. Verify and correct this – throughout the entire manuscript."
Added new descriptions of the symbols immediately after Equations (1) and (2). The nomenclature has been updated in order to increase its clarity and readability.
"All figures and tables should be cited in the main text – the best way is: the tables and figures should be placed in the main text after their first reference in the text."
All tables and figures in the manuscript have been shifted to after the first citation.
"There are energy costs calculated and discussed in the Section 3 and 3.1. What is the source of the mentioned energy prices? The authors should provide even short information about the source – are they related to the Finnish current prices ? It is not clear, difficult to identify – maybe reference to the appendix or bibliography…"
The energy costs in Section 3.1 and 3.2 are one of the output results from the used unit commitment and dispatch methodology, and no outside source is used. Added brief explanations of the energy prices in Section 3, as well as some minor changes to Sections 3.1 and 3.2, hopefully clarifying the issue.
"Future works should be shortly described in the Conclusions section."
Included possible future works in the Conclusions section.
Reviewer 3 Report
Dear Authors,
I must say that the paper proposes a very interesting study, with an actual and novel perspective with respect to the current scientific literature. The simulation has been very well designed and properly described. The results have been properly discussed, leading to interesting conclusions. Overall, the paper is very well written, with a proper structure, description of models and methods, and boundary conditions. The quality of figures and tables, as well as the quality of language (both grammar and style), are very good.
Round 2
Reviewer 1 Report
the Authors have improved the paper that now could be accepted for publication
Reviewer 2 Report
The Authors have effectively replayed for all of the remarks, suggestions and comments.
