Warehouses and distribution centres can realise great savings by implementing energy management systems. It has been estimated that properly run energy management programmes targeting energy efficiency can save five to 20 percent on energy bills without a significant capital investment. From small to large sites, these savings can represent thousands to hundreds of thousands of revenue each year, and many can be achieved with minimal cash outlay. Due to the size of warehouses and distribution centres, even small improvements can have a large positive net effect on the bottom line.

Where do the savings come from when implementing an energy management system? Poor power factor can act as a major energy drain. Inefficient use of supplied power can easily be overlooked because it has few outward signs. There are no blown fuses, tripped circuit breakers or failed electrical apparatus to alert facility personnel of a problem. Material handling equipment can be made more efficient with the use of high-efficiency motors and an energy management system that shuts down parts of the system automatically when not in use. If a conveyor is required, sensors detect incoming products and automatically start it up again.

By ensuring that equipment is used only when needed, companies can see savings from:

• Improved operating efficiencies.
• Less downtime due to undetected equipment problems.
• Extended equipment life cycle.
• Reduction of power draw.
• Lower costs of environmental compliance.

Energy-saving equipment for the warehouse

The cost of operating equipment in manufacturing facilities and distribution centres is an ongoing cost that requires a substantial amount of electrical power. Companies can reduce electrical demand by upgrading to energy-efficient equipment that utilises high-efficiency motors. Conveyors, sortation units, AS/RS, etc. can be powered by high-efficiency motors or high-efficiency variable-frequency drives.

Many warehouses and distribution facilities are extremely large and house material handling systems that handle varying sizes and weights of containers or products. An individual conveyor system could measure five to six miles. Managing and maintaining this equipment can be a challenge.

Facility managers are always looking for new ways to improve their performance in order to keep equipment running smoothly and efficiently. For example, depending on the complexity of the facility’s conveyor system, it could account for as much as 50 percent of a facility’s electrical load. Because of these systems’ huge use of electricity, it is a natural target for improving efficiency and saving energy.

One way to reduce power consumption is to retrofit existing conveyor motors with highly efficient, variablespeed motors that feature a ‘soft-start’, which reduces the mechanical shock to the conveyor belts when restarting, significantly cutting maintenance costs. In addition, the soft start alleviates the motors’ high draw of electrical current during a restart

While energy-efficient motors may be more expensive than standard equipment, the true cost of motors is not the purchase price, but the cost of daily operation. Over time, the savings provided by an energy-efficient motor can far outweigh its higher purchase price. Energyefficient motors are also generally more reliable, longer lasting and put less of a load on electrical distribution circuits.

Saving space saves on utilities

Vertical warehousing helps some companies beat the high cost of land, cut transportation costs and reduce the operation’s environmental impact. By building the warehouse up instead of out, the warehouse has a smaller footprint and thus saves on costs. A multi-storey warehouse allows a company to operate in a dense urban area, rather than locating miles from the population centre. Locating the warehouse near the end customer also saves on transportation costs.

Vertical equipment such as vertical carousels, AS/ RS, conveyors, etc. save on space in the warehouse. Automated storage and retrieval systems, such as vertical carousels and vertical lift modules, take advantage of unused overhead space to recover 60 to 85 percent of the floor space typically required by shelving and drawer systems. Improving space utilisation in a warehouse saves on the footprint of the building. By reducing the amount of space required for storage and retrieval operations, organisations can construct smaller, more energy efficient buildings, shrinking the construction footprint by up to 15 percent in some cases, conserving natural resources and reducing maintenance costs. This improved space utilisation helps reduce energy costs, which helps reduce an organisation’s overall carbon footprint.

Lighting and other energy saving tips

To lessen the load, remove one or two bulbs in lighting fixtures that take four or more bulbs. Lighting each bulb in the fixture isn’t necessary where lighting isn’t critical. Use timers or sensors so that lights turn off when no one is around that area of the warehouse. High-intensity discharge (HID) light sources, such as metal halide and high-pressure sodium lamps, have long dominated the market for lighting indoor spaces with high ceilings, but today other technologies have proven more efficient under many common situations.

For aisles, fluorescent fixtures (high-performance T8 lamps and ballasts) work best for heights of less than 6m. For locations requiring greater clearance and for many high-bay areas, fluorescent lights (high-performance T8 lamps or high-output T5 lamps) are usually the most efficient choice. LED lighting is the most efficient and has dropped enough in price to be cost-effective for many warehouses.

Painting walls white and installing windows to introduce natural light will improve light levels while reducing energy, provided the windows use thermal or double-paned glass.

The HVAC system is a huge drain on energy in a warehouse. If the warehouse is unoccupied much of the time, evaluate the level of heating and air conditioning really necessary to make the environment comfortable or store the company’s products. Oversized ceiling fans may be able to reduce temperatures in the facility. Regular maintenance, such as changing filters, is important for good operation and to avoid energy waste.

Dock shelters, which enclose the entire back of a truck are more energy-efficient than roll-up dock doors because they reduce outside air exchange. Dock shelters most likely won’t be found in warehouse facilities built on spec because they’re more expensive than typical loading docks. Regularly checking and repairing gaps in the seals around loading dock doors is a quick energy saver.

A warehouse with older insulation is losing energy to the environment. Traditional batt insulation can be replaced by more efficient spray foam or loose fill. Spray foam insulation is the most expensive, but is twice as efficient as batt. Loose fill is a middle alternative that is easy to install in existing spaces and still provides superior insulation.

Finally, don’t think of sustainability in terms of costs; think of it as an investment resulting in revenue savings – a better bottom line and a better image that win the respect of your customers and your community. •