Driving efficiency

15 October 2009

Once a valuable tool for dynamic process control, variable speed drives are increasingly being seen as a means to energy saving. Anna Mitchell talks to ABB’s Steve Ruddell about the industry’s changing attitudes.

ABB variable speed drives were recently used to control a water feature on the opening set of Take That’s stadium tour this summer.
ABB variable speed drives were recently used to control a water feature on the opening set of Take That’s stadium tour this summer.

“Historically [variable speed drives] were brought to the market in the early 70s in order to provide variable process control and energy saving, at that time, wasn’t a significant issue,” begins Ruddell. “However, in recent years the drives have been recognised as a major source of potential energy savings.”

Ruddell says the change is down to two reasons. “Firstly there has been a sustained focus on climate change,” he asserts. “Clearly the less energy you use in your plant then the less carbon you emit. Of course there’s a lot of EU regulation around the trading scheme and the carbon credit scheme that penalise plants for generating too much carbon emissions.

“And secondly, something that’s really bringing [the energy efficiency issue] into focus is the dramatic increase in the cost of energy bills and electricity specifically over the last three or four years. We’ve typically seen a trebling, if not quadrupling of the rate industry is paying per kilowatt-hour over the last three or four years.”

It’s not clear cut whether it’s legislation or cost cutting that’s providing the biggest push, but it is obvious that a combination of the two is starting to drive change in industry. Ruddell says that over the last 12 months the legislation has become far more focussed. “There is now regulation in place to penalise [carbon emissions],” he notes. “That’s got people talking about reducing their carbon footprint. Prior to that it was all about the money you could save. Of course the beauty with the variable speed drive is it does both. It saves you money but it also reduces your carbon footprint because it saves energy.”

Ruddell pinpoints the water industry as a sector that has been particularly proactive in the implementation of variable speed drives. “They’re probably the most aware of the potential for savings and footprint reduction that can be achieved with variable speed drives. I think it’s because they have a massive installed base of pumps to pump water and waste water around the system. Furthermore, Ofwat now regulates them and caps the rate they can charge for water. They have to continuously look for savings not only in their energy bills, but in their carbon footprint because most of the water companies qualify for the EU trading scheme as they are massive consumers of energy. For example [UK privately owned water company] Severn Trent’s energy bill for a year would be in excess of £50 to 60 million (€57 – 68 million). So if they can make savings on their energy it will equate to significant operational savings. It also means they can minimise their carbon emissions and hence pay less penalties to the EU trading scheme and the carbon credit scheme.”

As legislative and financial pressures conspire more and more companies are looking for energy saving solutions. Variable speed drives can offer huge benefits for companies that typically use a lot of energy on pump and fan control. According to Ruddell, with a technology that can generally offer pay back in less than two years, ignorance is the only barrier to widespread implementation.

Steve Ruddell is general manager of ABB’s drives, motors and machines division in the UK and is also the company’s energy spokesman in the UK

Contact Details and Archive...

Related Articles...

Print this page | E-mail this page