Energy Storage Sizing for Large Scale PV Power Plants Base-Load Operation - Comparative Study & Results

With greenhouse gas emissions increasing and global environmental policies changing, renewable energy sources have gained significant attention over the last 15 years. However, the intermittent nature of renewable generation makes its integration to the grid a challenging task. Thus, energy storage systems are usually proposed as a way to overcome this problem. This paper deals with energy storage for very large PV power plants (larger than 100MW). Different operating strategies have been defined for the PV power plant and the required energy storage capacity was estimated for each of them via a sizing methodology that will be briefly described. In addition, six areas of favorable solar radiation characteristics have been chosen as case studies to evaluate the presented methodology. Finally, a time series analysis was conducted in order to estimate the confidence interval for which both PV generated energy and energy storage are sufficient to fulfill the specific operating strategy. This analysis was performed for each operating strategy and location and thus, a comparative study will be presented.