Industry opinion Switch it off, turn it down
Simple measures to introduce energy effi ciency are often overlooked – but they can offer opportunities for contractors, says Steven Brambley, deputy director of GAMBICA
I
t’s a simple principle that we often apply in our homes to save energy, switching the lights off and turning the heating down. But it is not so widely applied in industrial motor applications, the single largest consumer of electrical energy in industry in the UK and worldwide. But leading businesses are now starting to see the value in getting their motors under control and saving signifi cant amounts of energy and money. Electric motors are used to power pumps, fans, compressors, conveyors, hoists and many other loads. They consume 66 per cent of all industrial electrical energy, so effi ciency is rightly becoming a high priority. Premium effi ciency motors will certainly save some energy but motor control is the part of the system that can often give the greatest effi ciency gain, simply by applying our initial principle – switch it off, turn it down. As hard as it is to believe, the majority of motors have almost no form of control other than an on/off switch, which in many cases is never in the off position. Imagine if your car had no accelerator pedal, just a hand brake to control speed; aside from the uncomfortable stop/start process for the passengers and the increased wear and tear on the vehicle, the fuel consumption would be dramatically increased as the engine revs at 4,000 rpm at each set of traffi c lights. It sounds ridiculous, but this sort of method is the most common way of using electric motors in industry. It might surprise you to learn that your average 11kW motor may cost about £500 to buy but £120,000 to run at 8,000 hours per year over a 15-year lifetime (and that isn’t even accounting for inevitable energy price increases). It’s worth considering the payback on any investment in motor control that will reduce this signifi cant running cost, such as variable speed drives, soft starts and automated starting/stopping. Payback times can often be less than one year and, of course, continue to give a saving over the lifetime of the system – particularly as energy costs increase.
Barriers
The question that often arises at this point is: ‘If the savings are so great, why don’t more people do this?’ It would appear to be a solution that fi ts into the ‘no- brainer’ category. The first hurdle, however, is the awareness of exactly how much energy is being used in a business and how much by motor systems. Even
where a business has this insight, it seems there are two main barriers that discourage the uptake in motor control, neither of which should stop common sense from prevailing. Nonetheless, all too often they do. The fi rst barrier stems from the economic climate and the level of uncertainty about future events and policy. Businesses are still reluctant to invest money in improvement projects, despite short payback periods and the ongoing benefi ts. Short-term focus is on reducing cost, not spending money, even to the detriment of future growth. This ‘make-do-and-mend’ attitude is often proudly touted as a strength, but it is ultimately a false economy. Saving money by cutting capital budgets, reducing staff and cancelling training is damaging to the business and morale, making it diffi cult to grow again when the opportunity arises. Saving money by reducing energy consumption makes a business more competitive while keeping key skills and resources.
Electrical contractors are in a great position to identify these types of energy saving opportunities for their clients
The second barrier is a focus on purchase cost, instead of lifetime cost. Whenever a business invests in a machine, a production line or a ventilation system, you can be sure they will have a rigorous process for getting several quotes, usually comparing price, with the lowest bid winning. Something that is not often evaluated is the lifetime energy cost of
About the author
Steven Brambley Steven Brambley is deputy director of GAMBICA, the national association representing the interests of companies in the instrumentation, control, automation and laboratory technology industry in the UK.
the system. Competing suppliers will seek to reduce the capital cost of the equipment but without considering the true cost for the operator, including energy consumption. What if the cost of automation and motor control added £700 to the purchase cost? Many suppliers will consider cutting this from the specifi cation. But what if that control saved £1,400 per year in energy? It could be sold to the customer as a more cost-effective quote. Electrical contractors are in a great position to identify these types of energy saving opportunities for their clients, saving them money, cutting their costs and enabling them to be competitive. I believe this kind of pro-active service is what will differentiate suppliers in the eyes of the customer.
GAMBICA produces guidance documents on motor control and other subjects, downloadable free from
www.gambica.org.uk/technicalpublications. For more information, contact Steven Brambley at GAMBICA on +44 (0)20 7642 8090, email sbrambley@gambica.
org.uk or visit
www.gambica.org.uk
July 2012 ECA Today 23
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