A Minimal System Cost Minimization Model for Variable Renewable Energy Integration: Application to France and Comparison to Mean-Variance Analysis

Round 1

Reviewer 1 Report

This paper deals with modelling the integration of electricity from intermittent renewable energy sources into the grid. It presents the design of a model that allows to perform the analysis in a simplified way without the need to model the whole system including controllable power generation plants.

The developed model can be used for a baseline assessment of the potential impacts resulting from the increasing penetration rate of VRE. I suggest acceptance of the paper after the minor revision – see below:

• The CF parameter is not in the symbol list
• Line 282: in practice it is necessary to consider also the variable costs of VRE - e.g. photovoltaic and wind power plants. Maintenance costs of e.g. wind power plants are often linked to operating hours. At least a brief discussion on the assumption of neglecting the variable costs of VRE is missing.
• Line 298: the meaning of the term "benevolent planner" is not clear
• It is not appropriate to use 1st person when describing the method
• Figure 1: unclear meaning of the image description (probability)
• Figure 11: too long figure description. Need to separate the figure title from the methodological commentary
• Line 510: the assumption of a discount rate of 4.5% needs to be discussed in more detail given that private investors are implementing the VRE project. Is this an appropriate rate of return on capital? It is not stated whether this is a real or nominal value.
• Figure 3: error in formatting of the graph caption, similarly Figure 7
• Line 585: error in reference to Fig. - repeated reference to Fig. 7j
• Line 680-713: this section belongs in Discussion rather than Results. In general, a change in the structure of the paper to improve its clarity can be recommended - more separation of the actual theory, from the discussion of the data for the case study, from the results and their comparison with other authors' results.

Author Response

Please find our reply in the attached document.

Reviewer 2 Report

The paper is interesting. The authors propose a model of VRE integration based on the minimization of a system total cost. The authors also apply their proposed model to the case in France. I think the model is well-specicified and useful. I agree with the article's suggestion and findings. Also, I recommend publishing this article since it will be interesting for the journal's readers.

Author Response

Please find our reply in the attached document.

Author Response File: Author Response.pdf

Reviewer 3 Report

The paper introduces a model regarding the variable renewable energy investment strategies and applies a simple version of the model to the country of France, examining the total and marginal costs.

I have find the paper very interesting but very complicated too. 

The manuscripts strengths are the amount of variables/parameters taken into account for the model and it's application to a real country/period. One weaknesses can be that the application model used for France is a simpler one, which -on the other hand- is understandable as in the real world many variables can not be known.

Please advice about the axis possibility in Figure 1 (like 100%) than 8700. The horizontal axis of Figure 1 is ambiguous, probability is usually taken from 0 to 1.

The abstract is very long. You need to limit the extend to the half of it, referring to a) introduction, b) the case until now and c) your proposal + result.

Author Response

Please find our reply in the attached document.

Author Response File: Author Response.pdf