Creating the 'green' automated warehouse
The increasing need for sustainability in logistics appears to be at odds with the increasing automation of warehouses and distribution centres. But Vanderlande uses five facts to demonstrate how ‘green’ improvements can be made in an automated warehouse.
Sustainability and logistics
The demand for sustainable solutions in the supply chain has increased greatly in the last few years. Under the ‘green’ theme, companies and governments have started a large number of zero emission campaigns with marketing, behavioural stimulation and/or operational cost savings as the leading motives.
Until now, the possible CO2 savings in air and road transportation was often chosen as an area of attention. As a result of the strong increase in the automation of warehouse logistic processes, the warehouse has now been placed on the agenda as well.
Assumptions and facts
Vanderlande’s 'Sustainability' internal working group began an investigation more than a year ago to make a baseline measurement concerning energy use in warehouses and to analyze trends in reducing the CO2 footprint.
Vanderlande first investigated the influence of automated warehouses on energy use within the entire logistics chain. Automated warehouses with miniloads, conveyors and sortation systems appear, on average, to account for 24% of the total CO2 emissions in the chain. Assuming a highly automated ‘goods-to-man’ based system with miniloads and conveyors, automation accounts for roughly half of this 24%.
Fact 1: Energy use of a mechanically processed order line is the same as for a manually processed order line.
Despite the fact that an automated order picking process with miniloads, conveyors and workstations uses more energy than order picking with, for example, an order picking cart, the energy use per order line is the same.
This is based on the following factors:
- Throughput per m3 of automated warehouse volume is, on average, three times higher than that for manual processing.
- Miniloads do not require heat, lighting or air conditioning to do their work. People do.
- Space utilization in an automated warehouse with miniloads or a shuttle system is 35% higher than in a manual warehouse with shelving or flow racks, because it makes better use of a facility’s height.
Fact 2: The building and the layout make the difference
For this, Vanderlande paid special attention to lighting, cooling, heating and the energy use of internal transport.
- Lighting Modern, sustainable lighting concepts save up to 50% energy compared to conventional lighting. Light-penetrating sections in roofs and walls, T5 tubes (less energy and a longer lifespan) and motion sensors instead of switches are often used in sustainable warehouse construction projects. Nowadays, a lot of attention is given to workstation lighting, because this increases productivity, keeps the workers alert and motivated. Vanderlande’s PICK@EASE high-performance order picking workstations with Philips Dynamic Lighting are a good example of this. By using brighter lighting for fixed workstations, the number of LUX used in the warehouse can be reduced by 30%.
- Cooling and heating The combined use of soil heat exchangers, improved insulation of roofs, walls and loading docks, the reuse of heat from compressors and other machines, and night-time ventilation form approximately 30% of the total potential energy savings. Automated warehouses gain even more from the fact that only workspace where workers are present has to be conditioned. Miniloads and conveyors operate in a ‘black box’ without the need for heat or lighting.
- Energy use of internal transport For example a forklift truck which, on average, moves 30 pallets with 40 cartons per hour: It consumes 1.3 Watts of energy per carton. With conveyors, the same transportation of 1,200 cartons costs approximately 1.1 Watts of energy per carton (and, of course, no personnel). Vanderlande’s latest DOTM conveyor range has been specifically developed to reduce the energy use of internal transport even further.
Fact 3: Overly optimistic growth expectations and peak scenarios result in an energy-inefficient system
Often systems are designed in such a way that their operational capacity is able to handle the peak hour load on the peak day 5, or even 10, years away. With the wrongly chosen assumptions, overly optimistic growth expectations and extra integrated system capacity, this can eventually result in an over-sized system, with an energy profile that is far from ideal.
If powerful motors are not used to capacity, they tend to use more electricity than a well proportioned system.
Fact 4: Insight results in improvements
To find out where the biggest potential cost savings lie, Vanderlande has developed a special Energy Scan, which can accurately determine the energy use in subsystems over time. The company took a closer look at two mechanized solutions:
- Sortation solutions for individual items and shipping cartons
- ‘Goods-to-man’ order picking solutions with miniloads and conveyors
Within the sortation solutions, the energy use of conveyors proves to be substantially greater than that of the sortation system itself. That is why Vanderlande has developed the new DOTM conveyor range which, by using different belts, drives and software, reduces energy use by 25-30%. In addition, Vanderlande’s new cross-belt sorter, CROSSORTER 1500, is 80% more energy-efficient than conventional cross-belt sorters.
In ‘goods-to-man’ order picking solutions, the miniload turned out to be an interesting area of attention. In cases with an average of 5 miniloads per system, more than 60% of the energy is consumed by these miniloads. With its QUICKSTORE miniload Vanderlande was able to reduce energy use by 20% by using lighter materials and by making use of acceleration and deceleration energy and gravity.
Fact 5: Clever controls software offers a great deal of potential
The system only has to run if something has to be stored, transported or sorted. By dividing all the equipment into a finely-meshed network of transport fields, which can be individually operated based on the flow of cartons, packages or totes, an average energy saving of 10% can be achieved. And it is also a lot more quiet in the warehouse.
To learn more about ‘green’ efficiencies in automated warehouses, visit us at CeMAT, hall 27, stand J34.