## 3 Methodology and Application to a Case Study
### PtG Scenarios and Circular Perspective  
Based on the socio-economic impact analysis carried out in this study, the potential impact of the deployment of PtG technologies in the medium and long term in Spain is presented in Table 7. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**2020**} & \multicolumn{2}{c}{**2035**} & \multicolumn{2}{c}{**2050**} \\  & **High** & **Moderate** & **High** & **Moderate** & **High** & **Moderate** \\  & **Deployment** & **Deployment** & **Deployment** & **Deployment** & **Deployment** & **Deployment** \\ \hline TOTAL t/d & 117,266 & 16,694 & 117,265 & 16,694 & 176,549 & 83,811 \\ TOTAL jobs & 3050 & 600 & 43,060 & 5580 & 50,830 & 20,610 \\ Average employment factor [jobs/(t/d)] & 0.51 & 0.45 & 0.37 & 0.33 & 0.29 & 0.25 \\ Employment factor for distributed installations [jobs/(t/d)] & 2.55 & & 1.85 & & 1.48 & \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Employment factors estimation (own elaboration from [78]). \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**2025**} & \multicolumn{3}{c}{**2030**} & \multicolumn{3}{c}{**2050**} \\ \cline{2-11}  & **Installed** & **CAPEX** & **CAPEX** & **Cost. CO2** & **Installed** & **CAPEX** & **Cost. CO2** & **Installed** & **CAPEX** & **Tools (Tot.** & **CityConsand** & **Tibosomal** & **CityConsand** & **Tibosomal** & **Flemes)** & **Capt. CO2** \\  & **(MW)** & **Euro)** & **FT Equars** & **Toms** & **(MW)** & **Euro)** & **FT Equars** & **Toms** & **(MW)** & **Euro)** & **FT Equars** & **Toms** \\ \hline \hline \multirow{2}{*}{
\begin{tabular}{c} Pessimistic \\ Technical \\ Business as usual \\ Optimistic \\ \end{tabular} } & 28 & 63/42 & 107 & 40 & 875 & 1,758,447 & 3200 & 1261 & 4800 & 6,268,308 & 13,581 & 27,675 \\  & 35 & 79,678 & 134 & 50 & 1260 & 2,512,068 & 4571 & 1802 & 8000 & 104,477,197 & 23,036 & 46,126 \\  & 56 & 127,484 & 214 & 81 & 2062 & 4,144,911 & 7543 & 2973 & 13,600 & 17,760,205 & 39,246 & 78,414 \\  & 70 & 159,355 & 268 & 101 & 2625 & 5,275,342 & 9600 & 3784 & 17,600 & 22,963,795 & 50,789 & 101,477 \\ \hline \end{tabular}
\end{table} 
Table 7: Estimated scenarios of the PG deployment in Spain and evolution of the main socio-economic impacts. To forecast the evolution of these indicators in different scenarios (5, 10, and 30 years), the factors that could accelerate or slow down the investments in these technologies in Spain need to be identified. These factors need to be corrected by a coefficient \(\lambda_{\text{x}}\) according to four different scenarios: pessimistic, technical, business as usual, and optimistic (Table 8). The business as usual scenario would occur in a context of moderate upgrade of the factors that may improve the energy transition and PtG, such as the maturity of technology (electrolytezer and methanizer) and the incentives for new installations (feed-in-tariff, regulation, etc.,). Technical scenarios are those calculated using data from the literature and/or based on technical evaluations. Similarly, a pessimistic scenario would represent a situation with barriers (high price of electrolyzer, payback period, etc.,) and no incentives. Finally, in the optimistic scenario, the expected variations in each of the temporal scenarios would be higher than that in the previous scenarios because barriers are overcome and the incentives are allocated from both energy transition and CE promotion, which would result in a significant increase in the CE in the territory. This methodology was designed in line with factors selected by [PERSON] et al. (2018) [76]. A high volume of investment is expected in the period of scenario 2 (from 2025 to 2030) in response to the energy transition goals and the European Green Deal Strategy [80], although its effects are cumulative in successive periods. Investment made at present will have positive effects in the future, in line with other eco-innovative investments in which the environmental positive effects are appreciated in the long term [81].