Harmony in storage: music-inspired, degradation-aware optimization for cost-reliable hybrid solar-battery systems

Battery energy storage systems play a vital role in decentralized hybrid renewable power schemes. This paper introduces “Harmony in Storage,” a music-inspired, degradation-aware Harmony Search (HS) optimization framework that enhances both the design and economic operation of off-grid hybrid solar photovoltaic-battery systems. By integrating adaptive, music-inspired parameters and explicitly modeling battery degradation and state of health (SOH), the framework generates more realistic and cost-reliable configurations. Optimal system sizes are determined under two scenarios, ignoring and incorporating degradation/SOH, with a focus on reducing power generation costs and improving reliability. The proposed model is validated through comparative analysis with Particle Swarm Optimization and conventional HS. Key algorithmic settings (number of runs, harmony memory consideration rate, pitch adjustment rate) are systematically explored, demonstrating up to 5.3% cost reduction and enhanced reliability through optimal tuning. When degradation is included, total annual cost rises by 5.87% and battery count by 5.98%, underscoring the necessity of degradation-aware design.