SUMMARY
The necessity of hybrid energy storage system design is shown. It is considered the main components of hybrid energy storage systems and their features. It is shown that these systems are characterized by a beneficial coupling of two or more energy storage technologies with supplementary operating characteristics. The hybrid energy storage systems may include super capacitors, flywheels, superconducting magnetic energy storage, lithium-ion batteries, fuel cells. It is analyzed the use of every possible component as a part of the hybrid energy storage system in different operating conditions. It is considered a sizing methodology optimization for hybrid energy storage systems based on blast algorithm and hybrid neural networks.