# Energy Transition on Sifnos: An Approach to Economic and Social Transition and Development
## 7 Conclusions  
The Sifnos Energy Community, through its initiative for rational and effective energy transition in the island, gained the distinction of the declaration of Sifnos as one of the six pilot islands of the European Commission. The hybrid power plant presented in this article features as the main symbol of energy transition on Sifnos. It exhibits three main innovative points, which designate it at the global level as a unique pilot project:  
* It is the first project involving a hybrid power plant based on the combined operation of a wind park and PHS system operating with seawater. * It is the first project with a sizing which aims at 100% electricity demand coverage in an autonomous, non-interconnected insular electrical system. * It is the first project which aims at 100% coverage of all final energy needs in an autonomous, non-interconnected island, implemented by a local energy cooperative scheme. The selected technologies, namely the wind park and the PHS system, are the only ones that can guarantee normal, secure and economically viable energy transition on the island. The sizing of the PHS system offers a storage capacity of 860 MWh, which imposes an autonomy operation period of 16 days, given the daily average electricity consumption. It also exhibits remarkably low levelized set-up cost, calculated in the range of EUR 30/kWh of storage capacity. The annual operation of the examined hybrid power plant was computationally simulated adopting an annual power demand time series, introducing the expecting power demand for full transition to e-mobility on the island. Through this process, it was shown that the hybrid power plant with the proposed sizing can fully address the electricity power demand on Sifnos, while at the same time maintaining the power production from the already installed and operating wind park and decentralized small photovoltaic stations. All of these power plants together offer a clear 100% annual electricity demand coverage. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Uncertainty** & **Probability** & **Potential Risk** & **Impact** & **Proposed Risk-Mitigation Measures** \\ \hline Electrical & High & Unnecessary & & The necessity of storage plants \\ interconnection of & (given the IPTO plans & construction of the & & increases even for the mainland grid \\ Sifnos & and announcements) & hybrid power plant & & with the increase in the installation of \\  & Medium & & & RES projects \\ Electricity selling & (given the necessity for & & & \\ price from the & both cheap electricity & economic viability of & & High & necessity of supporting these projects \\ hybrid power plant & and economic viability & the project & & with guaranteed selling prices \\  & of the project) & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Summary and evaluation of the uncertainties on the hybrid power plant implementation. The hybrid power plant's impacts on the natural environment and the human activities are almost eliminated. This is practically achieved with the proper siting of the system's components. The installation site was selected in cooperation between the scientific team and the founding members of the Sifnos Island Cooperative. Through this collaboration, both the technical parameters and the local environment sensitivities were considered, leading to an excellent result, both regarding the achievement of the project's objectives and the elimination of any potential impacts. Beyond its purpose as a power production plant, the project offers a wide range of developmental perspectives for the local community. These perspectives can be mainly approached through the exploitation of the remarkable annual energy surplus for potable water production with new desalination plants and hydrogen production which can be used for powering a new passenger vessel which will facilitate the daily maritime connection between Sifnos and its neighboring larger islands.