The Role of Local Citizen Energy Communities in the Road to Carbon-Neutral Power Systems: Outcomes from a Case Study in Portugal
Round 1
Reviewer 1 Report
there is a typo on line 748, the main difficulty, the 'y' is missing
I think the title should reflect that the case study is done for Portugal.
at line 93, we need the details of the legislation
the word 'legislation' is referred to quite a lot in relation to the EU (endnote 4, 24), would be good to actually have reference to the actual directives. what is referred to is a note, not the legislation
Author Response
"there is a typo on line 748, the main difficulty, the 'y' is missing"
The author thanks the reviewer for mentioning this error, that have been fixed in the last version of the manuscript.
"I think the title should reflect that the case study is done for Portugal."
The author agrees with the reviewer and thanks the reviewer for this pertinent comment, because the original title suggests a more theoretical paper, while one of the major contributions of the paper is the case study.
"at line 93, we need the details of the legislation
the word 'legislation' is referred to quite a lot in relation to the EU (endnote 4, 24), would be good to actually have reference to the actual directives. what is referred to is a note, not the legislation"
The author agrees with the reviewer and thanks the reviewer for these very valuable comments. Indeed, the missing of the legislation reference is a drawback of the first version of the manuscript. Now, we may find it in (endnote 23) together with general descriptions along the article and the formal legal definition of CEC in the beginning of section 3.
Reviewer 2 Report
This article presented a case-study that tested different CECs configurations using real data from Portuguese consumers, producers and market prices. The strength of the paper is its application oriented topic, which is actual and up to date. Also, the presented case study along with its description bring practical value and could be interesting for the readers. There are some remarks.
1. The main and biggest drawback, that paper is not concise. Its long length will not stimulate the readers to keep their attention. Therefore, it is better to shorten the manuscript parts whenever possible. Particularly, please consider the option to combine section 2 'The future of European electricity markets' with the Introduction. Some less important statements could be neglected or shorten. This point of view aims increasing the relative content of new and original findings in contrast to moderate decseasing the relative content of general and informational value data (currently presented in Sections 1 and 2).
2. The logical coherence suffers due to the time jumps within content structure (e.g. 'In 2016, the EU presented the “Clean Energy for all Europeans” ' in section 1 and 'In 2009, the EU presented the “Third Energy Package” ' in section 2).
3. Section 3 should be the core of the paper according to its title 'The role of local Citizen Energy Communities'. But it does not show the author's original contribution enough clear. Its significant part actually repeats of what have been already told in the previous sections (e.g. strings 217-234 similar to 25-39, etc.).
4. Please clarify regarding Table 2. Role of each member (M) or partner (P) of CECs and Table 3. Future flexibility options of CECs. Were these roles and options proposed by author or it was collected from the literature?
5. Some equations' and variables' description made me confusing, e.g.:
?? is the observed quantity at time ?, ?̂? is the forecasted quantity, ?? is the nominal power, quantity of what? power? than units of Q is W, kW or MW?
is it right that units of NRMSE in (1) are square root of seconds?
is it right that units of average deviation, ?̅d? in (2) are 1/second?
??? is the renewable generation of the CEC and ??? is the consumption of the CEC in (3), generation and consumption of power or energy? units are W, kW, MW or W*h, MW*h, GW*h?
6. Generally, the main contribution of the paper belongs to the sections 4, 5 and 6. Especially, conclusions are relevant and valuable for practical use. Please try to cut wisely the rest part of the paper in order to make it concise enough. The new original scientific contribution should be emphasized in detail.
7. The level of self-citation is 22% (i.e. 13 out of 59 references).
Author Response
"This article presented a case-study that tested different CECs configurations using real data from Portuguese consumers, producers and market prices. The strength of the paper is its application oriented topic, which is actual and up to date. Also, the presented case study along with its description bring practical value and could be interesting for the readers. There are some remarks.
1. The main and biggest drawback, that paper is not concise. Its long length will not stimulate the readers to keep their attention. Therefore, it is better to shorten the manuscript parts whenever possible. Particularly, please consider the option to combine section 2 'The future of European electricity markets' with the Introduction. Some less important statements could be neglected or shorten. This point of view aims increasing the relative content of new and original findings in contrast to moderate decseasing the relative content of general and informational value data (currently presented in Sections 1 and 2). "
The author agrees with the reviewer that the Introduction section should be shorten, more fluid and focus on the global problem of market design, forecast errors and the possible role of CECs. While in the first version of the manuscript there is a strong emphasis in the point of view of the EU, with details that should be mentioned only in section 2, now exists a shorten global overview about those issues.
Section 2 is important to describe the current market behavior of the EU players, why current European market designs are failing on integrating high shares of VRE without extra costs with renewable incentives, capacity mechanisms and system balance, paid by consumers. It is also important to describe the perspective of CECs as entities that could partially reduce local forecast errors and give the required flexibility that power systems with high shares of VRE need.
Furthermore, section 5 simulates the participation of CECs, consumers, prosumers and RES in the current market designs, so it is important to previously describe all market mechanisms used in this study.
- "The logical coherence suffers due to the time jumps within content structure (e.g. 'In 2016, the EU presented the “Clean Energy for all Europeans” ' in section 1 and 'In 2009, the EU presented the “Third Energy Package” ' in section 2)."
The author agrees with the reviewer and fixed this issue in the last version of the manuscript.
- "Section 3 should be the core of the paper according to its title 'The role of local Citizen Energy Communities'. But it does not show the author's original contribution enough clear. Its significant part actually repeats of what have been already told in the previous sections (e.g. strings 217-234 similar to 25-39, etc.).
- Please clarify regarding Table 2. Role of each member (M) or partner (P) of CECs and Table 3. Future flexibility options of CECs. Were these roles and options proposed by author or it was collected from the literature?"
Section 1 shortly presents the global perspective of CECs to partially solve some global problems of current market designs, while section 2 shortly presents this perspective from the point of view of the EU markets, having has outcome, that just by aggregating distributed consumptions and generation, CECs can reduce forecast errors, contributing for the system balance.
Section 3 goes deeply by indicating possible members and partners of CECs, their role, their private benefit and the global benefit (Table 2), explaining that "While members are part of the CEC, partners are players with they can establish agreements". The literature indicates possible flexibility solutions that can be provided by consumers, prosumers, EVs and VRE. This paper adapts those solutions from the point of view of the CEC (Table 3), a new legal entity.
Section 5 also illustrates that by being an active wholesale market player, CECs can be very advantageous to consumers, proving the benefits indicated in Table 2. The solutions presented in Table 3 were not tested, but the perspective is that through CECs will be more easy to engage consumers into those solutions than individually.
- "Some equations' and variables' description made me confusing, e.g.:
?? is the observed quantity at time ?, ?̂? is the forecasted quantity, ?? is the nominal power, quantity of what? power? than units of Q is W, kW or MW?
is it right that units of NRMSE in (1) are square root of seconds?
is it right that units of average deviation, ?̅d? in (2) are 1/second?
??? is the renewable generation of the CEC and ??? is the consumption of the CEC in (3), generation and consumption of power or energy? units are W, kW, MW or W*h, MW*h, GW*h?"
The author thanks the reviewer for this pertinent comment. Indeed, the quantity refers to energy (MWh) as can be seen in Table 5 (on page 14, while the first time quantity is mentioned was on page 5, which is not a good procedure). Now, it was stated as “quantity of energy” in the first time it was mentioned.
The nomenclature used to refer the nominal quantity (Qn) was wrong (previously indicated as nominal power), and new text was added to avoid confusion “For producers the nominal quantity of energy considers the produced energy at nominal power while for consumers it considers the peak energy consumption”.
As indicated in Table’s 1 caption, NMRSE and the average deviation are presented in %.
When referring to generation and consumption I am referring to generated and consumed energy (Q), so now, the nomenclature is concise.
- "Generally, the main contribution of the paper belongs to the sections 4, 5 and 6. Especially, conclusions are relevant and valuable for practical use. Please try to cut wisely the rest part of the paper in order to make it concise enough. The new original scientific contribution should be emphasized in detail."
Sections 2, 3 and 4 serve as support to section 5, it was not a good procedure to substantially cut section 2, while section 5 refers the day-ahead market, forecast errors (NRMSE), PPAs, Forwards and imbalance prices.
- "The level of self-citation is 22% (i.e. 13 out of 59 references)."
The majority of these references are previous work used in this article, presented as complementary work about market design [4,5,20,21,37] strategic bidding of RES and consumers [5,15,19-21,37,54], retail tariffs and extra costs with VRE’s incentives and capacity mechanisms [10,13,15].
Only 3 complementary readings about simple and complex offers [32], coalitions [52] and risk asymmetry [59] could be replaced by similar references.
Round 2
Reviewer 2 Report
The presented manuscript has been significantly improved and could be accepted for publication.
