## 2 Material and Methods
### Multi-Criteria Decision Support System (MCDSS) for Photovoltaic Set Identification
#### 2.3.3 MCDM Application and Output Data  
The equipment selection will be carried out using multi-criteria decision support methods, AHP and TOPSIS, to provide a customised installation proposal for each region, as well as the energy demand and specific requirements the user demands. Therefore, combining methods will assist users interested in generating their own energy, aiming to minimise installation costs and reduce energy demand so that only installation availability costs are charged. The methods allow and provide for the inclusion of qualitative parameters to indicate the preference of one criterion over another. Therefore, the user will be asked to determine the weights for the criteria evaluated by the decision methods, which must meet the consistency index. The criteria assessed by the multi-criteria decision support methods  
Figure 3: The daily average high (red line) and low (blue line) temperature, with 25 th to 75 th and 10 th to 90 th percentile bands. The thin dotted lines are the corresponding average perceived temperatures. Source: [57]. will be (i) system efficiency, (ii) installation cost, and (iii) payback period. All criteria have a direct relationship; for example, the most efficient system may have a higher initial investment, while a cheaper system may not guarantee a shorter payback period for the installed photovoltaic system. * System efficiency evaluation criterion--the method will indicate the equipment with the best energy utilisation. Priority will be given to photovoltaic modules that can obtain higher electrical power for a certain amount of solar irradiation. * Installation cost evaluation criterion--the decision will be to select equipment with the lowest cost. * Financial analysis and evaluation criteria will lead the method to prioritise a balanced installation, aiming to reduce the investment payback time. To conduct an economic analysis of the photovoltaic system to be installed, factors such as payback period, net present value (NPV), and internal rate of return (IRR) will be evaluated. To achieve this, it is necessary to verify the kilowatt-hour rate charged by the local utility company where the equipment will be installed. Due to the many alternatives, decision support methods will facilitate the decision-making process regarding which photovoltaic module and inverter model will be installed according to the user's needs regarding the evaluated criteria. Therefore, the first recommendation will be the quantity and model of photovoltaic modules that best match the user-entered criteria. Based on the power generated by the photovoltaic modules, the method will exclude some inverter models to avoid errors during selection. Inverters will be excluded if the energy generated by the selected modules is less than 80% of the nominal inverter power or 20% higher. This result prevents an improper choice by the method, such as recommending an oversized inverter based on the \"cost\" criterion when actual values are input. For the selection of a photovoltaic module alternative, various factors will be analysed, such as open-circuit voltage (\(V_{oc}\)), maximum power (\(P_{Max}\)), maximum power current (\(I_{Max}\)), area (\(a\)), efficiency (\(\eta\)), and cost (\(C\)), which will be compared to determine the best alternative. The exact process will be carried out to determine the best inverter alternative, where the analysed factors will include maximum power (\(P_{Max}\)), efficiency (\(\eta\)), maximum DC voltage (\(Vdc\)), and cost (\(C\)). The PV equipment selected by each decision support method will be presented and compared to verify if the chosen alternatives correspond to the trends provided by the user. Two comparisons will be made: first, the photovoltaic modules and inverters will be separately compared, and finally, the components will be integrated to generate the complete system for the final comparison. Each evaluated criterion's maximum and minimum values will be used for these comparisons, generating a range of values.