Storage and retrieval system

A storage and retrieval system, comprising:

• a) a grid framework structure comprising a plurality of storage columns for the storage of a plurality of stacks of storage containers, a track system comprising a plurality of tracks arranged in a grid pattern comprising a plurality of grid cells arranged above the plurality of storage columns for guiding one or more robotic load handling device on the grid framework structure, the plurality of the tracks being arranged such that each of the plurality of storage columns is below a single grid cell;
• b) a plurality of stacks of storage containers, each storage container of the plurality of stacks of storage containers comprising a bottom wall and upwardly standing sidewalls and end walls;
• each stack of the plurality of stacks of storage containers occupying a single storage column of the plurality of storage columns, the plurality of stacks of storage containers comprising a plurality of a first type storage containers comprising a metallic container body and a plurality of a second type storage containers comprising a wireless transmittable container body;
• and
• c) an environmental monitoring system comprising:
• i) at least one environmental sensor comprising a wireless communication device for transmitting environmental data, the at least one environmental sensor being stored in at least one of the plurality of the second type storage containers to define a sensor container;
• ii) a base unit external of the grid framework structure, the base unit comprising a wireless communication device for receiving the environmental data from the communication device of the at least one environmental sensor;
• wherein the plurality of stacks of storage containers are arranged such that the sensor container is adjacent at least one of the other of the plurality of the second type storage containers so providing a pathway to the outside of the grid framework structure for the transmission of the wireless signal from the at least one environmental sensor to the base unit.