# 222

Dear A. E. Dinçer |A.Demir |K.Yılmaz

I read your paper:

Enhanced Objectivity of AHP for More Reliable Solar Farm Site Selection

My comments:

1- In the abstract you say “Although the conventional AHP method mathematically ensures the consistency of results, the reliability of these results depends on the expert manifests”

Of course there is consistency of results, because AHP forces the DM to correct himself if there is inconsistency. It is “There must be consistency or you can’t continue”.

Where is the mathematic here?

It is impossible to measure the reliability of results because it is constructed with invented weights, and since there is nothing to compare them to, in order to extract a conclusion.

2- “by satisfying objective relations and/or consensuses about relations between criteria”

3- “In the AHP analysis, first, the relevant constants of criteria are specified, often depending on expert judgment and/or survey conducted for the specified region”

May I remind you that in AHP you must work with independent criteria? Unless you refer to relative importance between criteria

4- Page 2 . “There are some criteria [8] for the selection of suitable sites for applications: solar radiation rate, environment, orography, location, climate, esthetics [9], and so forth”

In my opinion solar radiation rate is not enough. Solar radiation involves three types of electromagnetic radiations: UV, Visible light and Infrared. The only important here is Visible Light and Infrared. The first is what really impacts cells to generate electricity output, Infrared only heats the cells and produces a decrease in output. Look what AI says about this:

From AI

Comparing Two Sites

Let’s say:

• Site A has high total irradiation (e.g. 1000 W/m²), but much of it is infrared or UV.
• Site B has lower total irradiation (e.g. 850 W/m²), but a higher proportion is in the visible and near-infrared range, which PV cells actually convert.

In this case, Site B could outperform Site A in terms of electricity generation—even though it receives less total energy—because PV cells are tuned to absorb specific wavelengths, mostly between 400–1100 nm”

5- “In the AHP analysis, first, the relevant constants of criteria are specified, often depending on expert judgment and/or a survey”:

I guess that by ‘constant of criteria’ you refer to weights. If so, who says that they are constant, which is other AHP assumption without any foundation? This assumption does not stand up to the slightest analysis. It is only a very convenient simplification for AHP, therefore, on top that weights are inventions of the mind, considering them constant is an absurd, why?

Suppose that the DM estimates that cost is 3 times more important than environment, and this could be fine for alternative A (construction of a high-rise). What happens for alternative B (construction of a road in a protected forest area, where obviously, the environment may be 2 times more important than cost, because its consequences?

6- “It is believed that subjective or irrelevant opinions are balanced by AHP”

In the real-world we are not working with beliefs but with facts.

7- “In the SDSS of solar farms, there are several criteria that are not directly related to each other. For example, in many previous studies, aspect and distance from roads are taken as criteria [17, 20, 37, 38]; however, these criteria are not directly related to each other and/or a completely objective comparison may not be possible”

I am puzzled by this sentence since it does not matter if criteria are or not related, all of them reflect characteristics of a site and mut be considered. If they are related, you cannot use AHP, and if they are you can use an y other MCDM method. If aspect is not related to distance and in you dismiss them, you are not considering a very important criterion like distance from road that affects a site. Who says that objective comparison is not possible? You can compare both with a certain aspect that is common to both. For instance, you can compare prices regarding quality and of course, it is not objective.

If you use SDSS along with GIS, why do you need to compute weights when the system can-do that for you? If you do not believe me pls enter in AI where it says

“If you're referring to SDSS as the Spatial Decision Support System and GIS as Geographic Information Systems, then yes—they can absolutely compute weights of criteria or layers with impressive accuracy” Why do you need AHP?, If you want to incorporate the human factor, you can do that by adjusting those SDSS weights according to expert human opinion, which is something valuable, but then, you will be working on a solid and visual base

8- “AHP is one of the most popular tools for MCE Application is straightforward for any area of research. However, it is a defective tool when used improperly as discussed by Cheng et al. [33]”

As you are doing now by not considering criteria independence in AHP

9- “But who can judge the expert on this irrelevancy or inconsistency? Should the expert revise their opinions regarding the relations between criteria based on the consistency analysis of AHP?

Good and honest question, by why then, you apply it?

With respect to your questions, the answer is: Of course not

It implies that an algorithm commands a human decision

Sorry, but it enrages me that a “mathematical’ method can suggest something so irrational. And you know why? Because if it is not transitive, AHP cannot apply Eigen Analysis.

10- “AHP- In OH, experts are only asked to give the importance order of the criteria”

On what grounds?

These are some of my comments. I hope they can help

Nolberto Munier