Applied Energy, Vol.235, 1351-1368, 2019
Curtailment-storage-penetration nexus in the energy transition
The nexus between growing shares of renewables (penetration), storage requirements, and curtailment was studied using a linear optimisation model. The study was performed using a dataset of Israel's electricity system. Five scenarios are designed to assess the techno-economic impact of curtailment under various policy-based frameworks. The results show that the three parameters are linked to each other in a way that necessitates simultaneous increase of a total loss (curtailment plus storage efficiency), penetration and storage capacity in the energy transition. Depending on the curtailment policy, penetration increases significantly with a small increase in storage capacity until it reaches a corresponding point of inflection. Based on these physical relationships, storage technologies were classified as diurnal and seasonal. Diurnal storage capacity continually increases to a maximum capacity of about daily average demand, which corresponds to a penetration of approximately 90% of annual demand where the deployment of seasonal storage significantly increases. Having no curtailment was shown to lead to higher total system cost as compared to the system optimised with curtailment. Overall, the nexus between the three factors was shown to define when to deploy and dispatch storage technologies. The evidence supporting these findings is detailed for the first time.