Copper for Energetic Efficiency

Use of larger amounts of copper in motors and transformers makes them more efficient because of the high electric conductivity of this material. According to the European Copper Institute (ECI) the main points were energy can be saved thanks to this material are electric motors, transformers and cables.

Electric motors: efficient electric motors (which have a higher content of copper) currently are only 12% of all electric motors in Europe. Typically, these motors’ life cycle is much more economic than that of conventional motors. If this is the case, why aren’t they more common? ECI exposes the following causes:

– Separate budgets for acquisition of new equipment and operational costs in most companies. If budgets are not coordinated within an integral analysis, new equipment is always bought as cheap as possible (and causes a higher cost in the long term).

– Lack of information on the Life Cycle Cost of available equipment.

– Old motors still kept as spares in some companies. When a motor in the production chain needs to be replaced, it seems logical to use one of these spares instead of buying a new one. However, the difference in operating costs is greater than the purchase price.

According to ECI, 200 TWh could be saved yearly (equivalent to the production of 35 nuclear plants) through substitution of existing motors with more efficient models. 10,000 million euros would be saved in operating costs, and an additional 50,000 million wouldn’t be needed for investment in new generation capacity.

Transformers: introduction of more efficient transformers would allow a reduction of 19 TWh in network losses (3 nuclear plants, 1,000 million euros).

Cables: energy saving in cables is not achieved through a higher content of copper in cables but thanks to their adequate sizing. It is well known that any energy flow through an electric cable has losses due to the Joule effect and that these losses are smaller in wider cables. However, wider cables means larger initial investment. According to ECI, the optimal size of any cable (the one which minimizes the sum of the initial investment and energy losses) is 3 sizes up from the size that is defined by the standard. This is probably only valid for cables that are to be used intensively: in the case of cables with and intermittent use energy losses are smaller in relation with the initial investment so a size greater than standard may not be adequate.

For more information, visit European Copper Institute