Just Change Suppliers?

July 10, 2008
How Do You Reduce Your Electricity Bill?

ABB took two slots at the June First Friday Club, the second to enable U.K. Drives & Motors general manager Steve Ruddell to renew his rant on the failure of industry in the U.K. and worldwide to appreciate the energy saving and carbon-footprint-reducing potential of variable-speed drives.

It’s just about understandable, if hardly laudable, says Ruddell, that the first reaction of 80% of CFOs to the question “How do you reduce your electricity bill?” is “Change supplier”; it’s downright depressing when 80% of engineers come up with the same answer. Changing suppliers can at best make a difference of pence whereas “reducing the speed of motors with variable-speed drives can frequently save over 50% of the energy used and, in extreme cases, as much as 90%, without detriment to the application,” he says.


How significant is that? Well, U.K. industry alone has an estimated 11 million motors installed with a total capacity of 90GW and accounting for some 40% of the country’s total electricity consumption. Motors driving pumps account for 32% of industrial electricity consumption, and fans, 22%, both applications where VSDs can result in very significant savings, but only 3% actually have any form of efficient speed control. “We’ve been giving out this message for 10 years, but it’s still not getting through,” says a clearly frustrated Ruddell.

One hope is that where energy savings, even at today’s eye- watering price levels, seem to have failed, carbon-foot-print reduction may touch even the flintiest CFOs green heart. To that end, ABB has introduced a simple on-line Carbon Foot Print Calculator at www.abb.co.uk/energy where engineers―or CFOs, for that matter―can determine the reduction in energy consumption, expenditure and emissions that can be achieved on their own motors by installing VSDs In one typical example, installing VSDs on the 30kW motors driving two pumps cut electricity costs by 75% and saved 80.17 tonnes of CO2 a year, the equivalent of 62 return flights from London to New York or 309,000 miles in the car.

As for trying to offset emissions, don’t even think about it, says Ruddell. To offset U.K. industry’s total energy consumption, he estimates, would require planting trees across twice the area of the Isle of Wight (380 sq km or 147 sq mi) every year!