A comparison between central- and self-dispatch storage management principles in island systems

TL;DR

This study compares central and self-dispatch strategies for battery energy storage in island systems with high renewable energy, finding central dispatch more cost-effective for similar renewable penetration.

Contribution

It introduces a comprehensive simulation framework comparing dispatch paradigms in island systems, highlighting cost benefits of central dispatch over self-dispatch.

Findings

Centrally dispatched BES systems are more cost-effective.

Optimal storage configurations depend on RES penetration targets.

Lower system costs achieved with central dispatch.

Abstract

This paper presents a comparative evaluation of central and self-dispatch management concepts for battery energy storage (BES) facilities in island power systems with a high renewable energy source (RES) penetration. BES facilities deployed to support the integration of additional wind capacity can be either centrally dispatched by the island System Operator or they can be self-dispatched within a Virtual Power Plant entity comprising renewables and storage, called a Hybrid Power Station (HPS). To explore the anticipated benefits of each BES management paradigm, annual simulations are performed for an example island system, employing a three-layer mixed integer linear programming (MILP) method to simulate the unit commitment and economic dispatch processes. The levelized cost of energy (LCOE) of combined BES and renewables investments is calculated and the achieved RES penetration levels and island system generation cost are evaluated, allowing the identification of Pareto optimal storage configurations, leading to lowest LCOE for a given RES penetration target. Overall, the centrally dispatched BES systems prove to be substantially more cost-effective, compared to the self-dispatched alternative, for achieving similar RES penetration levels.