One of the main problems facing logistics centres is the need for greater efficiency in terms of daily order throughput. With warehousing being favoured by increasing numbers of businesses, and with space being limited and often carrying a high cost premium, throughput needs to be continuous and fast – leaving no room for technical problems or power failure.
Companies such as electrical wholesalers, mail order retailers and industrial equipment suppliers have adopted national distribution centre models. Here, the central logistics sites can necessitate huge warehouses with their inherent energy, heating and lighting control challenges. The implications of failure of electrical equipment or the power supply can be catastrophic where the warehouse forms such a critical hub to a firm’s entire business.
Intelligent warehouse management systems can reduce these risks, by monitoring and metering both power supply and quality, as well as equipment efficiency. Such systems will protect the investment, prolong the life of motors, and minimise downtime.
Centres are coming under Government pressure to reduce energy consumption and to limit CO2 emissions. With about half of CO2 emissions coming from buildings, improving energy efficiency in warehouses is essential in meeting Government targets. Legislation, such as the Climate Change Levy, is being further reinforced by Part L2 of the building regulations – it focuses on the conservation of fuel and power in buildings – and the forthcoming Energy Performance of Buildings Directive.
Managers need not see these new laws as an upheaval, but should welcome the changes as an opportunity to contribute towards a better environment, enhance a company’s corporate reputation, and save themselves significant sums of money. Under the Inland Revenue’s Enhanced Capital Allowance (ECA) scheme, qualifying equipment and its associated installation costs can be offset against income tax in the first year of ownership.
The installation of specified technologies, such as variable speed drives (VSDs), often results in sufficient energy savings to pay for the equipment and its installation in less than a year. Typical applications of such motor controls are found in elevators, cranes and compressors. It is the ongoing duty applications, such as fans and compressors, to which the ECA applies. VSDs can bring huge energy savings anywhere electrical motors are encountered, given that 65% of electrical energy consumed is used in powering motors. Coupled with reclamation of capital outlay against tax under the ECA, real payback can be within eight months.
The focus for commercial buildings is moving away from capital expenditure to operational expenditure. Evidence suggests that a building’s operating costs amount to three times the capital costs; and these figures do not reflect maintenance costs that can be twice the capital build costs. Logistics centres are no different. Inefficient management of buildings during the operational phase wastes valuable energy and money. An Energy Savings Trust survey reveals that installing the technology to monitor and meter energy consumption has an average payback period of under six months. Investing in systems that can help reduce energy consumption can reduce operational costs.
Effective energy management is about more than just reducing utility bills. Empirical studies of metering solutions show an average of 5% reductions in utility bills in a diverse range of buildings, including warehouses – but this is just the beginning. Savings in the region of 2-5% can be achieved by better equipment use, avoiding unnecessary capital purchases, while improving systems reliability can save a further 10%. Moreover, an intelligent warehouse management system can also control and manage under and over voltages, supply losses, harmonic issues, maintenance savings, maximum demand avoidance and load shedding.
With a single convergent metering system on a Local Area Network, that can monitor gas, electricity, water, air and steam, all utilities can be tracked and monthly reports automatically generated. It is now possible to access this vital information through a web browser, either at the logistics centre or from a remote computer. It is also possible to set up alarms to notify the relevant person, either by SMS or e-mail, when a problem occurs.
Easy access to diagnostics means logistics managers can gain vital insights into the energy use of their warehouses and identify potential savings, enabling them to make decisions based on the facts.
By capturing events, it is possible to determine if a power quality problem exists, thereby averting problems and preventing deterioration. n
Gary Buckingham is with Schneider Electric. Tel: 01952 209600.