Of all resources on which modern manufacturing is dependent, energy is arguably the most fundamental. It is also a resource that has long been taken for granted. Rising energy prices and concerns over greenhouse gas emissions are increasingly leading operators to critically assess their energy usage. In many sectors, the potential for energy savings is minor and gains of a couple of percent in terms of energy efficiency are celebrated as breakthroughs. Under such conditions, the prospects of achieving major energy savings seem bleak. There are technologies, however, that can deliver very significant reductions. Foremost among these is a device that – at first sight – lacks the spectacular note of high-power, high-volume processes. It doesn’t make much noise or develop extreme temperatures or go through complex motions. In fact it sits in a cabinet and usually doesn’t even get a mention when the overall process is explained. However, it can cut energy consumption by 42 percent, and if applied in all rele- vant plants worldwide, it can deliver energy savings that equate to the electrical consumption of a country such as Spain. This device is the drive. The principle is simple: In the past, the motors that powered pumps were usually run at full power all the time, with the regulation of output being achieved through valves. A drive regulates flow through direct control of the electrical power fed to the motor, so permitting friction-based controls and the associated losses to be dispensed with. The following stories provide insight into several applications and show how drives technology can and do make a difference. The lack of system standards A lack of system standards for energy efficiency may result in up to 90 per- cent of pump installations being in- correctly sized – leading to wasted energy. N ow hold it,” you may say, “we have standards for everything”. Alas, the world is not that simple and in the area of energy efficiency there are still important gaps. The authors of this article were shown an ACEEE 1) presentation that made them aware of the fact that, whereas there are standards for pump designs 2) and for many for the hydraulic data such as developed head 3) , efficiency and NPSH 4) , the search for standards providing guidance in system design is less likely to produce a result. To use an analogy, if somebody were to buy a three-ton truck for use on shopping tours, it would not be a demonstration of energy efficiency – even if the truck selected boasted the best efficiency figures for three-ton trucks. The ACEEE presentation mentioned above refers to a study that looked in- to the internal practices of a leading chemical company and of two major engineering contractors that company used on recent projects. The focus of the study was to identify whether the size of the installed pumps matched the real need. The result showed that 90 percent of pumps were not correct- ly sized. This deficiency is a witness to the lack of standards or guidelines. If 90 percent of installations are incor- rectly matched in this company, how many are equally so in other compa- nies around the world? 1 illustrates the problem faced by system design engineers. When pro- jecting a system, there is a degree of Saving energy through drive efficiency Per Wikstroem, Jukka Tolvananen, Akseli Savolainen, Peter Barbosa Footnotes 1) ACEEE Summer Study on Energy Efficiency for Industry July 20, 2005 by Robert Asdal – Hydraulic Institute, Vestal Tutterow – Alliance to Save Energy and Aimee KcKane –Lawrence Berkeley National Laboratory 2) eg, HI, API, ANSI, ISO 3) The developed head is a measure of the mechanical energy per unit weight of fluid transferred by the pump. Numerically, the developed head is equivalent to the height to which the pump can elevate the fluid in a frictionless system. 4) NPSH: Net Positive Suction Head 73 ABB Review 2/2007 Energy efficient products