How energy recovery can reshape storage assignment in automated warehouses

In automated storage and retrieval systems energy in descending and deceleration phases of cranes can be recovered into the power supply system instead of being dissipated as waste heat. Such technological opportunity should be exploited by properly modifying control policies in order to improve energy efficiency of warehousing operations. In this paper the impact of energy recovery on the storage assignment process is analysed. A model of energy consumption with recovery is proposed so that each location within a rack can be associated with energy required to be served in a storage or a retrieval cycle. Shape and distribution of zone for energy-based dedicated strategies are analysed. Energy and picking time performances of different storage policies when AS/RSs machines are equipped for energy recovery are analysed and compared.