# Energy Transition on Sifnos: An Approach to Economic and Social Transition and Development
## 2 Methodology  
This article aimed to present the potential of energy transition in insular systems for social and economic transition and development, once planned and implemented appropriately, with the active involvement of local communities. To this end, the example of the Sifnos Energy Community was examined and presented as a pilot case.  
The article firstly presented the current energy consumption on the island, together with social and economic features which outline the weak points and the clear growth trend. Energy transition on Sifnos was designed on the basis of a major project, a hybrid power plant consisting of a wind park and a PHS system, thoroughly presented in Section 2, regarding its essential aspects: planning, operation algorithm and sizing. The sizing was executed according to a single and clear criterion: the ability of the hybrid power plant to fully undertake the electricity consumption on Sifnos. The goal was 100% real-time and annual electricity coverage from the hybrid power plant. No other dimensioning criteria were introduced. Once the operation algorithm was computationally simulated, the application was executed iteratively, by alternating the wind parks' power and the storage reservoir capacity, until the aforementioned target was met, with the minimum possible set-up cost. The introduced hybrid power plant was finally evaluated with the use of the Wind Farm R5 software versus its potential impacts on the natural environment and existing human activities aiming at their elimination, so as to ensure public acceptance and accelerate the licensing process period.  
This article also made extensive reference to the development perspectives on Sifnos, arising from the exploitation of the electricity production surplus from the hybrid plant. The excess electricity can support the full transition to e-mobility for the transportation on the island, the increase in potable water production through desalination plants and hydrogen production to power a daily voyage which will address insular isolation, especially during winter. The annual operation of the hydrogen production and storage plant was also computationally simulated, and it was designed to cover the annually required amount of hydrogen for the execution of the voyage on a daily basis. Through this analysis, the article proves the strong developmental perspectives created for the insular community via energy transition.  
Finally, the article was integrated with the analysis and discussions of two major uncertainties, with regard to the implementation of the hybrid plant: the forthcoming electrical interconnection of Sifnos with the mainland grid and the produced electricity selling price, which has not been configured yet. By accomplishing an essential economic analysis of the hybrid plant's investment and by considering several failure events that occurred in similar interconnected island cases, this article aimed to predict and set any potential risks and thresholds (e.g., for the electricity selling price), in order to ensure the feasibility and the economic viability of the proposed hybrid plant.  
The present article aspired to constitute a reference document on the way that energy transition can be transformed into a pillar for social and economic transition and development for insular communities.