## 3 Methodology and Application to a Case Study
### Main Socio-Economics Impacts
As it is usual to refer sizes and values of a PtG unit to the installed capacity of the electrolyser (2.8 MW in this case), estimated CAPEX draws was based on 2800 \(\upcels\) per kW of electrolyzer installed capacity in 2025 with an annual decrease of 2-2.5%. Table 5 summarizes the cumulative capacity and investment, and the total CO\({}_{2}\) capture and SNG production, at the end of each considered period. Concerning employment, the only reference to date regarding job creation from PtG assumes a value two times higher than that of a gas turbine [79]. From the authors' perspective, PtG technology is closer to that of hydrogen production (methanation is the reverse process of reforming) and employment generation is expected to be similar. The most definitive analysis of hydrogen production jobs was conducted in the United States (US), in which an estimation of the employment impacts of a transformation of the US economy to the use of hydrogen between 2020 and 2050 and under two scenarios is included [78]. Employment ratios for hydrogen production were calculated ad hoc from data reported in [78], which is the only report in which employment for a hydrogen economy was studied in deep. In the source document, two intensity levels of hydrogen deployment (high and moderate) are contemplated. Although the total jobs are classified as blue and white collar, aggregated data are given regardless of the eight technologies considered for hydrogen production. Because the total t/day of hydrogen \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **2025** & **2030** & **2050** \\ \hline PV plant & 1000 & 950 & 800 \\ Alkaline electrolyzer * & 676 & 581 & 318 \\ PEM electrolyzer * & 943 & 780 & 365 \\ Methanizer * & 779 & 632 & 274 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Installation costs of the different systems of a PtG unit (€/kW) (* own elaboration from [10]). \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Period**} & \multicolumn{2}{c}{**Cumulated PtG Capacity**} & \multicolumn{2}{c}{**Cumulated**} & \multirow{2}{*}{**Thousand Tons of**} & \multirow{2}{*}{**Nm\({}^{3}\) of SNG**} \\  & **(Expressed as Installed & & & \\  & **Photovoltaics MW)** & **(Thousands of G)** & & \\ \hline Up to 2025 & 35 & 78,587 & 50 & \(26\times 10^{6}\) \\
2025–2030 & 1285 & 2,559,062 & 1903 & \(962\times 10^{6}\) \\
2030–2050 & 9285 & 12,918,601 & 55,437 & 28,027 \(\times 10^{6}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Installed capacity, investment, CO\({}_{2}\) captured, and synthetic natural gas (SNG) produced. produced can be estimated, an average number of full time equivalent (FTE) jobs required to install, manufacture, and maintain each t/day of hydrogen produced was calculated. Table 6 shows the compiled data for the calculation of the employment factor in jobs per t/day of hydrogen production. It can be seen that employment factors for high and moderate deployment levels (line 4 of Table 6) do not change significantly as a consequence of being indexed to a unit of production. Moreover, employment ratios decrease over time as expected: as industries become more mature, they gain economies of scale, the cost decreases, and the improvement of learning curves implies fewer employees are required for the same level of production. These estimated employment factors are an average for all technologies and sizes. However, the proposed installations are expected to be more labor intensive because they are small and spatially distributed. In the work of the Department of Energy [78], several kinds of installations for hydrogen production are contemplated, ranging from distributed electrolysis (small capacity, 1.5 t/day) to nuclear thermochemical (high capacity, 768 t/day), and estimated jobs are reported.