VSDs reduce energy use by 30 per cent

This information comes from Gambica, the Trade Association for Instrumentation, Control, Automation and Laboratory Technology in the UK.

British industry and commerce can add GBP4.5bn a year to its bottom line, a three per cent growth in profits, by implementing a single, simple energy-saving measure; fitting variable-speed drives to electric motors.

While managers in UK industry are aware of the scale of rises in electricity prices and the environmental consequences of its excessive use, there is limited knowledge of how electricity costs can be effectively reduced.

Electric motors consume huge amounts of electricity; about two-thirds of all industrial energy use.

Even a simple electric motor, costing a few hundred pounds, can be expected to consume many tens of thousands of pounds worth of electricity over its useful lifetime.

Most power in electric-motor use is consumed in powering fans, pumps and compressors.

Such devices can be found in air conditioning and ventilation systems, boilers and compressors, which are located in most commercial and many domestic buildings, as well as in heavy industrial plants.

Using a VSD allows the speed of these motors to be accurately controlled and optimised for the application, resulting in typical efficiency improvements of 30 per cent.

But a relatively small percentage of potential users have actually implemented the technology.

Modern VSDs are widely available, proven devices that have never been easier or quicker to install, with the latest models using automatic tuning and setup features.

Unlike most energy-saving initiatives, the installation of variable-speed motor controls delivers 100 per cent return on capital employed (RoCE) and moreover, because of the rising costs of energy and the stable prices of the technology, the return on investment (RoI) is generally delivered in less than one year.

A further incentive is that, when installed in variable-torque applications, variable-speed drives qualify for tax relief in the form of enhanced capital allowances (ECA) from HM Revenue and Customs.

This means the full capital costs of equipment and its installation can be offset against income tax in year one.

The use of variable-speed drives is therefore one of the most easily implemented and cost-effective ways to achieve carbon reduction to meet the obligations under the Carbon Reduction Commitment.