Staying afloat on the rising tide of energy costs
01 November 2011
As rising energy costs continue to squeeze operating margins, companies must start to look closely at energy efficiency initiatives in order to remain profitable. Phil Burge turns his attention to the construction of electric motors, which account for 66 per cent of all factory energy consumption
As we struggle to cope with tough economic conditions, the pressure on companies faced with rising energy costs mounts as prices look set to jump by 15 per cent over the course of this year. With the Office of National Statistics recently putting factory gate inflation at 5.7 per cent, attention must now turn to taking costs out of each business in order to remain competitive.
Alternatively, this advice can be ignored and the costs passed on to the consumer; but then this does run the risk of being priced out of the market altogether. For manufacturers to remain competitive, a more sustainable approach to production processes through investment in energy efficiency is the wisest course of action. Some measures can be surprisingly simple and cost-effective, offering considerable cost savings and not necessarily involving a major investment programme.
Energy is a key issue for many businesses, so any action taken to reduce consumption will have a significant impact on the bottom line. For example, electric motors account for up to 66 per cent of all factory energy costs, so replacement with newer, more efficient models and ensuring that motors are correctly sized for their application are sensible first steps.
Another option is the installation of variable speed drives to better match energy use to varying loads and speeds. However, such steps can be costly in terms of initial investment and training.
Increasingly, equipment designers and operators are finding they can gain significant efficiency advantages by concentrating at the component level. For motors, this cheaper option might include the replacement of existing bearing units with energy efficient bearings. This will pay dividends, so long as an effective installation and replacement plan is carried out during routine maintenance to avoid additional downtime.
Depending on operating conditions, these bearings can save at least 30 per cent of frictional moment compared with standard bearings and in some applications 50 per cent or more, while operating temperatures can be up to 30oC cooler, depending on speed. This improved performance also provides additional benefits, including longer grease life and extended re-lubrication intervals, further reducing maintenance and running costs.
With ISO standard dimensions, the bearings can be incorporated into existing motor driven equipment such as pumps, compressors and fans as well as new systems extremely easily, again keeping development and installation costs down.
In addition to saving money, new efficient components have the potential to reduce the environmental impact of industrial applications significantly by reducing carbon footprints. With industrial activities taking up about a third of the world’s electricity capacity, component replacement appears to be a good starting point.
Phil Burge is with SKF
Energy efficient bearings – a case study
The latest generation of energy efficient bearings has been specifically engineered and manufactured for maximum efficiency. SKF E2 deep groove ball bearings, for example, are able to deliver significant energy savings, thanks to three design features: optimised internal bearing geometry, a robust polymer cage and the use of special low-friction grease. Mechanical friction is reduced, allowing the bearing to run cooler than standard bearings at equivalent loads and speeds.
For example, when GlaxoSmithKline Consumer Healthcare introduced SKF E2 bearings to a cold water pump motor, it achieved a return on investment in just 17 days. Installed in 22kW motors running at 2,990rpm, the bearings were able to deliver savings of 0.56kW per hour, which has subsequently resulted in an annual energy saving of 4,583 kWh per motor. At today’s electricity rates this amounts to an approximate saving of £600 per motor, per year.
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