# A Heuristic Approach to the Decision-Making Process of Energy Prosumers in a Circular Economy
## 3 Case Study and Method
### Avoiding electricity network dependency;
#### Reducing environmental impact using renewables.
As they were all assisted by installers when calculating financial attractiveness, price (C2.1) and payback (C2.3) displayed the same level of relevance, but the latter featured a wide range of responses. Access to financing (C2.2) appeared more important than the investment level. Moreover, operation and maintenance costs (C2.4) and regulations (C2.5) had a higher weight in the final decision. Figure 3: Relevance level (average and range) of economic and financial factors. Figure 2: Relevance level (average and range) of global factors in the post-installation phase. Answers to the open-ended questions suggested that the unknown performance of the PV installation and the little trust in future regulations had a high weight in the final decision. As these were noncontrollable variables, their judgement was consequently subjective. Finally, the degree of relevance in the PV adoption decision with respect to general access to information (C3.1) and other aspects such as maintenance of the installation (C3.2) (notice that this question is a control question which was already included as C2.4), simplicity of the installation (C3.3), employment generation (C3.4), and role of the installer (C3.5) was requested. Answers are shown in Figure 4.  
A majority of the responding PV owners considered the five factors to be \"very relevant\" (4) or \"totally relevant\" (5), leading to the conclusion that investments in these facilities are highly sensitive to the existence of clear and accessible information that reduces uncertainty in the final decision. In other words, information networks play a significant role in reducing the subjective or attitudinal factors. As the average values in Figure 1 were not conclusive enough to establish any sort of predominance among the economic, autonomy, and environmental criteria, interviews were examined individually. For each of the 16 interviews, factors C1.3, C1.4, and C1.5 were ranked to analyze their relevance (Table 3). The relative weight of each factor assigned by the respondents was expressed as a percentage, thereby identifying C1.5 as the factor considered most relevant by most prosumers. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Case.** & **C1.3** & **C1.4** & **C1.5** \\ \hline
1 & 33\% & 33\% & 33\% \\
2 & 22\% & 33\% & 44\% \\
3 & 29\% & 36\% & 36\% \\
4 & 33\% & 33\% & 33\% \\
5 & 33\% & 33\% & 33\% \\
6 & 42\% & 42\% & 17\% \\
7 & 38\% & 38\% & 25\% \\
8 & 33\% & 25\% & 42\% \\
9 & 33\% & 33\% & 33\% \\
10 & 42\% & 17\% & 42\% \\
11 & 23\% & 38\% & 38\% \\
12 & 33\% & 33\% & 33\% \\
13 & 38\% & 23\% & 38\% \\
14 & 33\% & 33\% & 33\% \\
15 & 33\% & 33\% & 33\% \\
16 & 23\% & 38\% & 38\% \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Ranking of the relevance of the three factors provided by the prosumers. Figure 4: Relevance level (average and range) of information-related factors. In summary, all three factors were taken into account during the decision-making process, with slightly greater relevance afforded to environmental motivation. Figure 5 shows the factors classified using the heuristic approach outlined in Table 1. The relevance level reported on average by interviewees is also included for consideration. In addition, factors were also grouped according to their natural influence in terms of the three global criteria involved in the final decision. The following conclusions arise after evaluating the typologies of the factors under study:  
* The economic criteria are only based on contextual factors that are known, accessible, and usually accurate, such as installation costs or energy consumption data for the calculation of payback. However, access to financing seemed to be the main economic concern as its relevance level was comparable to the overall economic criteria. * The autonomy criteria are linked to external factors for which reliability is key for the final decision.