More energy must go into making devices efficient

The technology exists to make devices far more efficient, but a number of factors are standing in the way, says Wayne Lyons
Written by Wayne Lyons, Contributor

People are only too ready to accept highly inefficient devices, even though the technology exists to provide significantly improved power consumption, says Wayne Lyons.

Inspired by the prevailing green buzz, the technology industry, businesses, governments and consumers are looking for ways to reduce the carbon footprint of domestic and business devices.

This mood has helped drive technologies like virtualisation, as well as specific projects such as IBM transferring heat from a Swiss datacentre to a public swimming pool.

Yet away from headlines, users almost never question the energy-consumption of electronic devices, even those that are highly inefficient. In the consumer electronics industry, the pervasive nature of devices ultimately means that today's connected home is responsible for a huge amount of energy waste. This trend is also reflected in the inefficiency of a range of electronic devices in business use.

Mechanised waste
More than 60 percent of industrial and nearly 40 percent of domestic electricity is used to drive electromechanical motors. These motors are found in a range of devices — from industrial fans and power tools to disk drives, printers, vacuum cleaners and treadmills.

The size of electric motors varies greatly, as does the amount of energy they consume. Electric wristwatches contain some of the smallest and lowest powered motors, whereas the huge devices used in the propulsion of large ships consume thousands of kilowatts of energy.

However, despite these differences in scale, many electromechanical motors have one thing in common — they are not energy efficient.

Electromechanical motors run with only speed control and many are oversized with no consideration of load. Most appliance motors today have a single speed and go on and off frequently, such as an air conditioner or a fridge, and hog power on start-up — enough to dim the lights in some cases.

However, embedding smart motor controls into devices would, in less than a decade, save Europe up to 341 billion kWh, 82.8 million tonnes of CO2 or €30.9bn (£26.4bn) per year at the European average in electricity costs. That saving equates to the total annual power output of 64 600MW power stations.

New motor technologies, generally known as brushless DC motors, or BLDCs, are slightly more expensive than equivalent induction motors, but rising volumes would help close this gap. More importantly, a substantial increase in efficiency would very rapidly pay for the small substitution cost.

An added advantage of BLDCs is that their speed is very easy to control, enabling the use of smaller motors and the development of quieter machines.

BLDCs are the result of a combination of advances in motor technology and electronics, and manufacturers of motors and electronic microcontrollers worldwide are working on new, more energy-efficient designs.

Drive to energy efficiency
In the same way as the incandescent light bulb directive by the European Commission has led to the replacement of traditional GLS light bulbs, a mandate by Brussels may help drive the adoption of more energy-efficient electric motors. The total saving available from such a directive would be much more dramatic than that achieved by the light bulb initiative.

Yet the availability of a new technology or regulatory pressures from Brussels may not necessarily result in a rapid and widespread adoption across Europe.

Ultimately, the influence of thought leaders in the technology, industrial and business sectors — as well as consumer pressure — is needed to convince device manufacturers to shift to more energy-efficient motor technologies and encourage the replacement of the installed base.

Such a drive would not only help our emissions challenge, but also make European industries more cost competitive.

Wayne Lyons is global director of embedded solutions at microprocessor design company ARM.

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