Matching intermittent electricity supply and demand with electricity storage - An optimization based on a time scale analysis.

The rising share of Variable Renewable Energy Sources (VRES) in the electricity generation mix leads to new challenges for the whole energy system. It especially raises technological issues to handle variability and to match electricity load with supply at all times. This study introduces a new methodology to quantify the relevance of different electricity storage technologies, based on a time scale analysis. It additionally provides an understanding of how electricity storages work in combination to handle variable load and intermittent generation. First, we set up a simple model of variable production, fluctuating over a single time-scale. This analysis provides figures of merit for electricity storage and curtailment. Second, we simulate the collaboration and competition behavior of various storages with a dual time-scale signal. Then, results are compared with the optimization of an energy system with real variable electricity supply and consumption time-series. We eventually highlight the trade-off mechanisms between the storage efficiency and its investment cost. • A parametric study is conducted on electricity storage for intermittent production. • Long-term electricity storage requires very low-cost technologies. • Short-term storage can afford higher costs if efficiency is high. • The optimal solution can involve two different storages for long and short terms. • Oversizing & curtailing the production can be more relevant than long term storage. [ABSTRACT FROM AUTHOR]