Driving energy efficiency further

Automation plays a major role in ongoing development processes, and electrical drive technology makes a vital contribution. The rapid pace of development in electronics and IT systems has significantly broadened the range of applications. The spectrum now includes anything from simple drives with or without electronic speed control to energy recovery systems and high-precision solutions offering excellent dynamic performance during positioning and motion sequences on material handling and production systems.

Distributed architecture, networking, user-friendly engineering tools and system integration are some of the major trends in electrical drive engineering. Web technologies and wireless communications are becoming increasingly popular in production environments. The deployment of web technologies emphasises the importance of wireless data transmission security. Designers can embed safety functions (safe stop, start lockout, etc) into the drives and merge process and operator functions to simplify commissioning and ongoing operation.

Development of the energy markets influences selection of motors

In the past, energy efficiency was essentially ignored during the drive and motor selection process. Energy was cheap compared to other production costs, and it was readily available. There was no demand for energy-saving technology that came at a price.

The situation has changed dramatically in recent years. Events in the energy markets, coupled with a growing awareness of environmental issues and the need to conserve resources, have significantly increased the political pressure to save energy.

Energy-efficient drives can make a vital contribution to these conservation efforts.

The German Electrical and Electronic Manufacturers Association (ZVEI) estimates that modernisation of existing industrial, commercial and municipal systems in Germany could reduce energy consumption by 27.5 billion kWh/year. That is equivalent to 11% of total industrial electricity consumption, and the annual savings would amount to 2.2 billion euros. Over a period of 10 years, users could save AU$4.2 billion (without factoring in any price increases). Three-quarters of the potential savings is based on electronic speed control, and the other quarter would result from the deployment of high-efficiency EFF1 class motors.

Electronic control reduces emission of carbon dioxide

As a replacement for mechanical butterfly controls or throttle valves, electronic speed control can significantly reduce energy consumption by ensuring that the motor does not draw more power than necessary at any given point in time. Four-quadrant inverters support regenerative braking.

There are huge opportunities to save money. It is regularly claimed that electricity accounts for more than 90% of life cycle costs. The purchase price is well under 10% of total cost.

Great need for modernisation

It is estimated that around a third of installed drives which are used in industrial and municipal applications are not energy efficient and need to be modernised. The main opportunities are in standard applications for auxiliary functions such as pumping, ventilating, compressing, conveying, moving, cooling and air conditioning. Electronic speed control and deployment of EFF1 energy-efficient motors could reduce energy consumption by 20–50%. The payback period for modernisation or replacement can be less than a year or up to four years.

From the engineering point of view, it would make sense to provide electronic speed control on 50% of new drives which are sold to industrial users. Currently, only 20–25% of new industrial motors have a frequency converter, and only 12% are energy-efficient EFF1 motors. That is not nearly enough.

Energy efficiency should become a part of corporate philosophy

How should industrial and commercial users approach the issue? The first step is to make energy efficiency an integral part of company policy and create mechanisms for implementing the policy. The next step is to take an inventory of installed equipment, record or estimate machinery energy usage and identify the worst offenders. Based on this information, the company can develop engineering solutions, identify specific opportunities to save energy, conduct a payback analysis and generate an energy-efficiency action plan. The plan can then be integrated into medium-term investment planning.

Energy efficiency should be part of the main selection criteria in the pre-selection process for new equipment. The specifications should specifically list energy consumption in kWh/year or /production unit. Each new machine should be fitted out with an individual meter to allow for subsequent cost tracking and to support ongoing data acquisition.