Hybrid storage systems combine two technologies, for example one for large amounts of energy and one for high power. Their benefit had mostly been shown in individual case studies. A general, application-independent assessment was missing.
- Setting: Leibniz University Hannover, Institute of Electric Power Systems, Electrical Energy Storage Systems group
- Status: dissertation submitted and graded, defence at the end of November 2026
- Tools: Python, Pyomo, GLPK, IPOPT, pygmo, computing cluster with SLURM
Content
- Theoretical sizing limits: when a hybrid storage system can be smaller than a single one
- A benchmark set of representative load profiles for unbiased comparisons (ESTSS)
- Representative energy management strategies derived from a meta-review
- Comparison of four strategy classes (filter, deadzone, MPC and fuzzy logic based) in about 10,000 configurations: typically 3 to 10 % oversizing compared with a reference with perfect forecast. Sizing and strategy design can be separated with little loss
- Effect of efficiency and self-discharge in more than 800,000 parameter configurations: compared with a loss-equivalent single storage system, sizing gains rarely exceed 3 %, while losses are often reduced by more than 20 %. Statistically, both are best explained by the coefficient of variation of the load profile (correlation ≈ 0.9)
Outcome
- Dissertation: Hybrid energy storage systems: a generalized quantitative analysis with a focus on system sizing
- Six journal articles as first author, open-source software and data: see About