# The Potential for the Use of Hydrogen Storage in Energy Cooperatives
## 5 Conclusions, Limitations and Future Research  
### Conclusions  
The transformation of the power sector is geared towards the decentralization of the power generation sector and a complete shift from the use of fossil fuels to renewable energy. These changes are increasingly taking the form of a revolution rather than evolution, forcing us to search for often unconventional solutions to help build energy independence. Its elements include the need to store energy as efficiently as possible and for as long as possible. The research the results of which are presented in the paper were focused on analyzing and evaluating the feasibility of storing energy in quasi-island systems with the use of a hydrogen-based power-to-power chain. The results clearly indicate, both for the four sample energy cooperatives and for randomly selected communities of different sizes, that it is technically feasible to select such a capacity of generating sources (in PV, wind, and mixed scenarios) along with the capacity of hydrogen storage that will guarantee energy self-sufficiency of a given energy community throughout the year. The process takes into account storage efficiency. Commercial application of the results would provide an effective equivalent to the current model of supporting prosumers that use the distribution grid as an \"energy storage\". \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & & & & & & & & & \\ \hline \multirow{2}{*}{**CASE**} & \multirow{2}{*}{**PV**} & **MIX** & & & **PV** & & & & **WIND** & \\  & & **WIND** & **MSC** & **PV** & **WIND** & **MSC** & **PV** & **WIND** & **MSC** \\  & & **kW** & & **MWh** & & **kW** & & **MWh** & & **kW** & **MWh** \\ \hline
0 & 16.672 & 28.056 & 6.025 & 51.965 & 0 & 12.329 & 0 & 47.796 & 8.236 \\
1A & 18.246 & 39.212 & 13.931 & 81.049 & 0 & 28.073 & 0 & 65.237 & 16.117 \\
1B & 49.262 & 54.828 & 1.607 & 108.983 & 0 & 18.642 & 0 & 80.779 & 5.271 \\ \hline \hline \multirow{2}{*}{**CASE**} & \multirow{2}{*}{**PV**} & **MIX** & & & **PV** & & & **WIND** & \\  & & **WIND** & **MSC** & **PV** & **WIND** & **MSC** & **PV** & **WIND** & **MSC** \\  & & **kW** & & **MWh** & & **kW** & & **MWh** & & **kW** & **MWh** \\ \hline
0 & 13.268 & 30.159 & 6.000 & 51.446 & 0 & 13.243 & 0 & 45.769 & 7.150 \\
1A & 16.125 & 39.774 & 13.894 & 81.939 & 0 & 30.311 & 0 & 61.870 & 14.876 \\
1B & 32.654 & 70.631 & 1.560 & 106.841 & 0 & 21.385 & 0 & 90.692 & 3.810 \\ \hline \hline \end{tabular}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**CASE**} & \multirow{2}{*}{**PV**} & **MIX** & & & **PV** & & & **WIND** & \\  & & **WIND** & **MSC** & **PV** & **WIND** & **MSC** & **PV** & **WIND** & **MSC** \\  & & **kW** & & **MWh** & & **kW** & & **MWh** & & **kW** & **MWh** \\ \hline
0 & 15.660 & 28.558 & 5.926 & 51.593 & 0 & 12.548 & 0 & 47.157 & 7.697 \\
1A & 17.449 & 39.151 & 13.35 & 80.539 & 0 & 28.562 & 0 & 64.174 & 15.223 \\
1B & 44.371 & 58.615 & 1.413 & 108.113 & 0 & 19.304 & 0 & 83.994 & 4.318 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Scenario-based characteristics of the selection of the type and capacity of generating sources and the storage capacity in EC2–EC4. Particularly interesting seem to be the optimization results indicating, for the hybrid generation scenario, a clear potential to reduce hydrogen storage capacity by several times compared to the \"conventional\" scenario, while increasing the capacity of generating sources. This is also interesting in terms of increasing the use of cable pooling, i.e., the presence of both PV and wind generation on a single power connection. Increasing the capacity of generation sources, at the cost of reducing storage capacity, significantly affects the profitability of such an investment--the latter and the costs associated with it were not analyzed as part of the study. The environmental aspects of the search for the optimum energy independence scenario for local energy communities and the impact on the external environment, including the grid operator in particular, are also worth highlighting.