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Saving energy with motors and drives There is estimated to be over 10 million motors installed in the UK alone, accounting for some 65% of industrial electrical energy consumption. Of all these motors, it is estimated that only some 3% are controlled by variable speed drives and yet the energy savings from such drives can be staggering - over 50% is not unusual. Hence the reason that the UK government is targeting pumps, fans and compressors - the main beneficiaries of drives and motors - as a way to save energy. Understanding the legislation; determining whether your drives and motors are operating at maximum efficiency; and deciding whether or not you need to take action has been made easier with the introduction of a 6-step Energy Saving Plan from ABB (contact: 0700 2 266722). Part of the 6-step plan shows many real-life examples, some of which are highlighted here: AC drive benefits HVAC cooling tower fans Cooling towers typically use banks of fans, each feeding cooling cells. In the cells the fan moves outside air through a spray of water, allowing heat to dissipate from the water. A 100 kW motor operated for 4,000 h/year and using a variable speed drive experienced savings of 200,000 kWh/year and 100,000 kg/year reduction in CO2 emissions. High efficiency motors replacing standard efficiency ones An UK water company cut its motor electricity costs by 6% after introducing a motor management policy, which helps identify energy wasting motors and gradually replace these with high efficiency units. The utility uses about £25 million of electricity per year, a large proportion of which is consumed by pump motors. Following tests, it was found that in many cases a standard efficiency motor could be replaced, prior to failure, with a high efficiency motor and still achieve payback in less than two years. Top of the page