Colloquia

Summary

This thesis presents a comprehensive assessment of battery energy storage viability for energy arbitrage in the Spanish electricity markets. The primary objective is to develop a robust methodology to evaluate various battery storage technologies under Spain’s market conditions. A multi-criteria scorecard approach is employed to compare seven battery technologies across technical and economic metrics previously defined as KPIs, leading to the identification of three promising candidates—lithium iron phosphate (LFP), vanadium redox flow battery (VRFB), and sodium–sulfur (NaS)—for in-depth analysis. 

Using a Python-based simulation framework, the operational performance and economic returns of these three technologies are modeled across multiple market segments, including the day-ahead market, intraday auction sessions, continuous intraday trading, and secondary and tertiary balancing services. The simulations incorporate key technical factors such as round-trip efficiency losses, charge/discharge rate (\emph{C}-rate) limits, capacity degradation, and lifetime energy-throughput constraints. A detailed degradation model is integrated into the simulations to represent performance decline and associated costs over the system’s life, ensuring that the arbitrage strategies reflect real-world aging effects. 

Results highlight significant differences in viability among the technologies: LFP batteries deliver strong economic performance owing to high efficiency and moderate cost, while VRFB systems—thanks to virtually unlimited cycle life and decoupled energy/power scaling—show competitive advantages in high-cycle applications despite lower efficiency. NaS batteries offer value in longer-duration arbitrage scenarios, though their viability is tempered by operational constraints. Overall, \textbf{LFP and VRFB emerge as the most viable technologies} under current Spanish market conditions, each excelling within distinct operational niches. 

The methodology developed herein provides a market-aware, simulation-based decision-support tool for investors, utilities, and policymakers, enabling informed investment and planning decisions regarding energy-storage deployment and arbitrage strategies in the context of Spain’s evolving electricity markets.