Determining the optimum installation of energy storage systems in railway electrical infrastructures by means of swarm and evolutionary optimization algorithms

•Swarm and evolutionary algorithms are used to improve DC-electrified railway systems.•The algorithms find the optimum installation of ESSs (location and power).•The algorithms are combined with a very realistic railway simulator.•The performance of Genetic, Particle Swarm and Fireworks Algorithms is compared.•Energy savings and considerable installation’s profitability are obtained.