*3.2. The Research Procedure*

To solve the research problem and achieve the research goals, the authors based on a triangulation of the research methods [23]. Triangulation uses several research techniques to analyse a given issue to increase the credibility and accuracy of the results, and as a result, give a thorough understanding of the phenomenon under study. They conducted the empirical qualitative research and applied the foresight method [1]. Such diverse perspectives justify approaches similar to those adopted by authors of other studies regarding ESCO [3,18,27,46,47].

The authors also realised the appropriate desk research analysis based on the literature. They found data concerning the documentation of the implementation of European programmes financing projects in the field of energy and analytical reports on the implementation of the ESCO formula in Poland and abroad.

In terms of qualitative research, a combination of the following research techniques was applied:


In terms of the foresight method, the authors applied a panel of experts. The expert panel is one of the key foresight methods, carried out in the form of a panel discussion with the participation of a wide group of specialists in a given field. During such a meeting, various positions are confronted, knowledge is accumulated, and, for example, recommendations and proposed solutions are developed [52]. An expert panel was applied in research focused on zero-emission vehicle technologies recognition [53]. The authors organised the panel to verify the validity of the detailed findings resulting from other research techniques but also to confirm the final conclusion and recommendations.

The qualitative research was conducted between 2017 and 2019. It covered a sample of 6 experts and 68 entities implementing or intending to implement projects based on the ESCO formula, including:


The selection of the research sample was non-random. We selected the representatives of the respective target groups (local governmen<sup>t</sup> units and companies) in two ways:

• the authors conducted desk research and social media analysis to recognize what entities deal with ESCO; those entities were invited to participate in the research as respondents;

• the authors used the mailing list prepared by the Ministry of Energy; those entities were invited to participate in the research as respondents.

In total, we found about 75 representatives of the target groups, but not all we available to participate in the research (in-depth individual interviews, CAWI surveys and focus group interviews).

The distribution of entities covered by the study on the map of Poland is presented in Figure 1 below.

**Figure 1.** The distribution of entities covered by the study on the map of Poland (local governmen<sup>t</sup> units-in red, enterprises-in blue).

The research procedure was carried out in four stages as presented in Table 1.

Based on the scenarios organized according to the research questions, the authors conducted both in-depth interviews and focus group interviews, recording all of them. The authors then prepared transcriptions and analysed the scope of the text based on the following procedure:



**Table 1.** The research procedure. Source: own elaboration.

It should be highlighted that the above research approach was chosen in agreemen<sup>t</sup> with the Polish Ministry of Energy [24] that commissioned and funded the research. The research was undertaken for the purpose of a general diagnosis of the factors influencing the interest of Polish entities towards implementing energy projects using the ESCO formula, as well as the identification of business models related to implementing energy projects using the ESCO formula in Poland. These are the reasons that the authors based their research on qualitative research instead of quantitative research. Qualitative research was more efficient thanks to its methodological approach, and provided sufficient results much faster than quantitative research. Additionally, using one of the foresight methods enriched the study and provided objective results, verified not only from the perspective of the target groups but also taking the feasibility of the recommended solutions into account, which were assessed by experts.
