A storage system for storing product items , comprising; a grid structure ; a number of storage bins configured to be stored in vertical compartments in the grid structure , where each storage bin is configured to contain at least one product item ; where the storage system comprises a picking and/or supply station ; the storage system comprises a conveyor system configured to convey a storage bin from a first position (P1) to a second position (P2) and further to a third position (P3), where the second position (P2) is a picking and/or supply position of the picking and/or supply station ; the conveyor system comprises a first, tiltable conveyor configured to convey the storage bin from the first position (P1) to the third position (P3) via the second position (P2); where the tiltable conveyor is configured to receive the storage bin at a first height (H1) of the first position (P1), to move the storage bin to a second height (H2) of the second position (P2) and to deliver the storage bin at a third height (H3) of the third position (H3), where the first height (H1), the second height (H2) and the third height (H3) are different from each other; characterized in that the storage system comprises a vehicle configured to move horizontally on top of the storage grid ; the vehicle comprises a lifting device configured to lower a storage bin vertically from the top of the grid structure to the first position (P1) and configured to elevate a storage bin vertically from the third position (P3) to the top of the grid structure ; where the first and third positions (P1, P3) are provided vertically below two different vertical compartments of the grid structure . a grid structure ; a number of storage bins configured to be stored in vertical compartments in the grid structure , where each storage bin is configured to contain at least one product item ; where the storage system comprises a picking and/or supply station ; the storage system comprises a conveyor system configured to convey a storage bin from a first position (P1) to a second position (P2) and further to a third position (P3), where the second position (P2) is a picking and/or supply position of the picking and/or supply station ; the conveyor system comprises a first, tiltable conveyor configured to convey the storage bin from the first position (P1) to the third position (P3) via the second position (P2); where the tiltable conveyor is configured to receive the storage bin at a first height (H1) of the first position (P1), to move the storage bin to a second height (H2) of the second position (P2) and to deliver the storage bin at a third height (H3) of the third position (H3), where the first height (H1), the second height (H2) and the third height (H3) are different from each other; characterized in that the storage system comprises a vehicle configured to move horizontally on top of the storage grid ; the vehicle comprises a lifting device configured to lower a storage bin vertically from the top of the grid structure to the first position (P1) and configured to elevate a storage bin vertically from the third position (P3) to the top of the grid structure ; where the first and third positions (P1, P3) are provided vertically below two different vertical compartments of the grid structure . <EOS>