machine building & automation - Industrial Technology Magazine

John Richardson’s ENGINEERING DIARYWe all knew that the Government’s Spending Reviewwould hit the public sector hard. Despite thereassurances of how most of the job cuts will comethrough retirement and voluntary redundancy, thereseems little doubt that there will be job losses that are moredifficult to palate. Still, we have been speaking about the need fora rebalancing of the economy for some time. So are we seeingrecognition of that need? As ever, as far as the UK’smanufacturing sector is concerned, it seems there is a sting in thetail. For all the talk of successive governments about theimportance of manufacturing to the economy in bringing us out ofrecession and generating growth, the people at the top don’tseem to be able to resist the temptation to squeeze just a little bitmore from our industries.A change to the Carbon Reduction Commitment (CRC) schemeincluded in the government’s Spending Review has made itsuddenly become even more important for companies to cut theirenergy bills. Monies raised through a levy on major energy users,that were intended to be redistributed to companies who haddone well in reducing their energy consumption, will now goinstead to the Treasury, alongside general taxation. Andy Parker-Bates of Parker SSD Drives says: “Companies that thought theyhad a guaranteed chunk of money coming in through the CRCwill now have to find a replacement. Few markets are so robustthat turning up the sales wick will produce prompt results, so thebest option is to crank up the energy reduction measures alreadyin hand.” Chancellor George Osbourne said that this move was toreduce bureaucracy, but omitted to say how it would affect theprivate sector companies he says he wants to help. (Calculationssuggest that a moderately large company could be £100,000 outof pocket). “The CRC only came into force six months ago,” saysParker-Bates. “Many people have only just worked out a strategyfor being a winner under the scheme, getting a payback greaterthan the levy paid.“It’s tempting to say that Mr Osbourne has made everyone aloser, but there is a definite positive to this. The most sensiblething to do is maintain or even increase the proposed investmentinto energy saving technology and reap rewards that way.”An energy audit will identify areas where energy usage can becut and how to do it. If there is an investment, paybackcalculations will help to identify a schedule of projects. Somethings, like reducing leakage from compressed air lines andturning off lighting when no one is present can produce largesavings at little or no investment. “Most companies will havegone through this phase a few years ago,” reckons Parker-Bates.“But fitting inverters to motors and similar technical solutions stillcreate many more opportunities for energy savings.”Naturally, production companies with manufacturing orprocessing plant will have many motors to be assessed, butmotors are also found in air conditioning systems, driving pumpsin the plumbing, and many other pieces of equipment. All ofthese have the potential for significant energy and cost savings.“Many motors are left running continuously, even through thenight and at weekends; while others could be switched off for anotable proportion of their duty cycle,” says Parker-Bates. “Veryimportantly, it should be noted that a motor’s energyconsumption is proportional to the cube of its running speed. Socut its speed by half and you save 80 percent of the energy.There are huge numbers of motors in British industry that wouldbenefit from the installation of an inverter.”Parker-Bates identifies another strategy, too: “Considerreplacing the motor itself.” Motor efficiency has improved steadilyover the last 10 years, so any motor over a few years old may beinefficient by modern standards. Motors also tend to loseefficiency with use; another reason for considering renewal. “Untila couple of years ago it was common practice to oversize motorsso that they had a bit of extra ‘umph’ should it be needed. Butthis disregarded the increased energy demand. Nowadays, itsconsidered better to use a correctly sized motor and control themotor with a variable speed drive.”feedback@itmagazine.uk.comNovember 2010 • INDUSTRIAL TECHNOLOGY49