Optimum wind- and photovoltaic-based stand-alone systems on the basis of life cycle energy analysis

The main aim of the specific research is the comparison of the energy pay-back period of optimum renewable energy sources (RES)-based configurations, meaning wind-battery and photovoltaic-battery stand-alone installations that may ensure the energy autonomy of a typical remote consumer under the condition of minimum life cycle (LC) energy content. In this context, energy autonomy is first ensured on the basis of an appropriate sizing methodology, while accordingly, by developing a calculation algorithm for the estimation of the LC energy content of such energy autonomous systems, minimum LC embodied energy configurations are eventually obtained. On top of that, three representative areas are examined so as to investigate the influence of the local wind and solar potential. According to the results, the sustainable character of both RES-based solutions is designated, especially when comparison with the conventional diesel-engine solution is carried out. On the other hand, the situation is inversed when comparing stand-alone and grid-connected RES systems of the same size, with significant contribution of the battery storage component being reflected.