Multi-Stage Integration of Renewable Energy Technologies into Standalone Energy Systems

Renewable energy integration into energy systems have been widely discussed in recent literature. Stand-alone micro-grids can play a vital role in this context. However, design optimization of such hybrid energy systems is a challenging task. Most of the recent studies use the techno-economic and demand data at the beginning of the project to optimize the system configuration for the micro-grid, which is expected to operate for more than twenty years. Changes in demand, advances in technology, prices of system components and fuel along the timeline are not considered in these studies, which often lead towards unrealistic results. In order to address the aforementioned limitations, the design process of a standalone micro-grid is divided into several stages and taken into discussion in this work. System design is optimized in three stages considering the changes of market prices of the system components and demand. Subsequently, each design is analyzed in detailed for a case study in Greece. Results of the study reveal that a significant change in Solar PV (PV) and battery energy storage system (BESS) capacity can be observed when moving ahead on the time line when considering the changes in market conditions. Accordingly, major change in the operation strategy is observed. However, projected price reduction in energy storage is not sufficient to use it as a seasonal or diurnal storage, which results in poor utilization of PV energy during the summer.