Brussels has once again taken the driver's seat and is tightening energy efficiency targets to achieve progress in climate protection. As stipulated in the EU directive, energy efficiency is to be improved by 32.5% by 2030 and overall consumption clearly reduced. Negotiators from the European Parliament, EU Member States and the EU Commission reached the agreement on June 19, 2018. As is often the case with policies from Brussels, these targets are quite ambitious. It is thus worth looking at where the major energy consumers are to be found.
In industry, the major consumer is obviously the product group ‘rotating equipment, comprised of pumps, compressors, fans and ventilators: According to a study conducted by the Fraunhofer Institute ISI, 30% of the electricity used in industry is used to power pumps while compressors and fans use 24% and 14% respectively. In total, rotating equipment thus ‘consumes’ two thirds of the electricity used for industrial purposes!
One thing is clear: obtaining additional efficiency gains by optimizing hydraulics has become very expensive. On the other hand, the drive unit, process measuring and control technology and specific software and cloud solutions have become considerably more important.
How are improvements in the 'old technology', the drive technology, over the past few years to be explained? Of note are three developments: the use of more material in the copper-stator winding of asynchronous motors or of copper in the rotor as well (there are naturally limits with respect to costs and weight), the reducing of losses in the motor (electrical resistance in the windings, eddy currents, mechanical friction losses in bearings) and, last but not least, the use of other motor designs (synchronous motor technology).
Permanent magnet synchronous motors do not need any additional energy for rotor magnetization - temperature-stable high-performance magnets provide constant magnetization. Thanks to the rotor's high energy density, the design of the copper stator can be much more compact, which saves resources. Thanks to these features PM motors use up to 30% less motive power than a conventional asynchronous motor. Yet another special feature: PM motors lose virtually none of their efficiency, specifically in the partial load range – unlike older asynchronous motors that virtually collapse under the same load.
Synchronous reluctance motors require no magnetic materials, are simple in design and very quiet. Like permanent magnet synchronous motors, they are rated as IE5 class motors and also run very efficiently in the partial load range.
Tip: The use of efficient technology is clearly regulated for new drive systems by the Ecodesign and Motor Directives. What is not addressed are existing systems. Experience shows that drives systems installed in existing installations offer great savings potential. This is why it is often worthwhile to replace technology that is still in working order.
The switch to energy efficient technology is naturally associated with investment costs. But because the payback period is generally short, the operator profits from substantial savings in the years to come given the long service life of pumps.
According to a study conducted by the Fraunhofer Institute ISI, 30% of the electricity used in industry is used to power pumps while compressors and fans use 24% and 14% respectively. In total, rotating equipment thus ‘consumes’ two thirds of the electricity used for industrial purposes (Chart: ISI).