About Copper & Energy EfficiencyTheres no better solution than copper when it comes to improving the energy efficiencyof electrical products.Copper is one of the most reliable and efficient media for transmitting electric power.Electricity flowing through copper wires meets far less resistance than it would inaluminum or steel wires of the same width. In fact, copper is a better electrical conductorthan any other metal except silver, making it the most economical and efficient electricalconductor available. Using copper wires results in lower electrical transmission losses,thus conserving energy and reducing demand on generating capacity, which ultimatelybenefits us all!As demands for electrically operated machines grow, consumers worldwide will naturallyseek more energy efficient devices. Apart from saving on electricity bills, extensive useof copper in home construction will maximize safety, security and efficient energymanagement.Conserve for tomorrowWasted energy needlessly depletes natural resources. It is expensive. It negativelyimpacts on the pocket books of people, companies, and national economies.And it requires fossil-fueled power plants to work harder, thereby emitting moregreenhouse gases and contributing to climate change. For all of these reasons, it is criticalto find new ways to improve energy efficiency.Switching to energy-efficient equipment, such as high- and premium-efficiency motors,high-efficiency transformers, and appliances requires only a modest additionalinvestment. But that investment will more than pay for itself in reduced energy bills,usually within a short time.Outstanding conductivity aside, copper possesses a number of other advantageousqualities as well. Copper is easy to work with and far more corrosion resistant thanaluminum.ElectronicsIBM and others are replacing aluminum with copper in the computer chips theymanufacture. Because of coppers superior electrical conductivity, this breakthroughtechnology enables conductor channel lengths and widths to be significantly reduced. Theresult is much faster operating speeds and greater circuit integration - up to 200 milliontransistors can be packed onto a single chip. Power requirements are now reduced to lessthan 1.8 volts, and the chips run cooler than ever before. The use of copper conductors inthe chip is the last link in a now unbroken copper chain comprising the electronic datapath between user and computer. From external cables and connectors to bus ways toprinted circuit boards, sockets and lead frames, its all copper.
Since their invention early in this century, electron tubes have depended on copper andcopper alloys for their internal components. In spite of the dominance of semiconductors,some $2 billion worth of vacuum tubes are manufactured annually. They include thecathode ray tubes used in TVs and computer monitors, voltage rectifiers, audio and videoamplification and broadcast applications, and the magnetrons in microwave ovens.Radio and television signals are carried to transmission antennas by hollow conduitscalled wave-guides. Wave-guides made of oxygen-free, high conductivity copper are30% to 40% more efficient than their aluminum counterparts.The National Security Agency buildings at Ft. Meade, Maryland, are sheathed withcopper to prevent unauthorized snooping. Even the windows are fitted with copperscreens. The copper blocks radio waves from penetrating into or escaping from the spyoperation. Copper sheathing is also used in hospitals to enclose rooms containingsensitive equipment like CAT scan, MRI and X-ray units to prevent problems related tothe entrance or emission of errant electromagnetic radiation.On a smaller scale, copper strip is used to shroud electron tubes, transistors, integratedcircuits and even complete electronic chassis to prevent radio frequency (RF)interference.Electricity & EnergyWeight for weight, outside of precious metals, copper is the bestconductor of electricity and heat, it is hardly surprising that about 60% of total copper useis for these purposes.Copper is used in high, medium and low voltage power networks, and copperconductivity is considered to be the standard to which other conductors are compared.Blister copper is 96-99% pure, but there is a way to purify it further, through a techniquecalled electrolysis. The unique combination of strength, ductility and resistance to creepand corrosion establishes this non-ferrous metal as the preferred and safest conductor forwiring in buildings. As an essential component of energy-efficient motors andtransformers, it is used in a multiplicity of applications in manufacturing industries, allforms of transport and the domestic environment.Wire & CablesAluminum cables are being replaced with copper ones, because copperconductivity is twice that of aluminum, making copper cables extremely energy efficient,thus helping reduce energy consumption on a global level.Copper wire has long been the preferred conductor material in the majority of cables usedfor power and telecommunications. Having high conductivity combined with a ductilitythat makes it easy to draw down to close-tolerance diameters, it can also be readilysoldered to make economic, durable connections. It is compatible with all moderninsulation materials but its good oxidation resistance means that it can also be usedwithout any surface protection.Insulation can be of lacquer or enamel types used for winding wires or of polymers forenergy cables. Lacquers permit close spacing of windings to give best efficiency in thecoils of motors, transformers and chokes.
BusbarsBusbars are robust conductors that function as electrical manifolds to distributepower from a single source to several users. Because of its good conductivity, strength,ductility and resistance to oxidation, copper is the most obvious material to specify forthe manufacture of busbars.High conductivity copper billets are hot extruded into a regular cross section, followed bydrawing down to the necessary finished size.Transformer and motor windingsCopper used for the manufacture of transformerwindings is in the form of wire for small products and strip for larger equipments.For small products, such as magnet wire, the wire must be strong enough to be woundwithout breakage, yet flexible enough to give close-packed windings. Strip products mustbe of good surface quality so that insulating enamels do not break down under voltage.Good ductility is essential for the strip to be formed and packed while good strength isneeded to withstand the high electro-mechanical stresses set up under occasional short-circuit conditions.The properties needed for motor windings are similar to those needed for transformers,but with the additional requirement to withstand mechanical vibration and centrifugalforces at working temperatures.Heat exchangersWith thermal conductivity allied to high electrical conductivity, copperis ideal for the manufacture of heat exchangers of all types. It is easily fabricated, easilyjoined and has excellent corrosion resistance. Typical applications include radiators, aircoolers and air conditioning units in transport; heat sinks for electrical equipment;calorifiers for domestic and industrial water heating and refrigeration units.Electronic equipmentWhile this sector is relatively small in terms of tonnage, copperplays a vital role in a number of small, high-tech applications.Copper or copper-base alloys are used in Printed Circuit Boards, in electronic connectorsand leadframes. In addition, it has long been used in the area of telecommunications, andis now increasingly used in IT, notably for the manufacture of microchips and in semi-conductor applications.Copper heat sinks allow dispersion of heat from high-frequency microprocessor and logicdevices.Other electrical engineering usesCopper is also used for manufacturing commutators,welding electrodes, contacts, contact springs, high vacuum and other electronic devices.Power losses in electrical equipment are due to electrical resistance in conductors andlosses in the magnetic material which occur primarily in motors, transformers and in allcabling. Copper is one of the key materials to be considered when work is being done toimprove the energy efficiency of electrical equipment. High conductivity is one of itsmost important properties and 60% of copper currently produced is used in electricalapplications. Copper magnetic wire is widely used in the motor industry, whileelectronics is successfully developing copper-based semi-conductors.
Identifying opportunitiesThe identification of energy saving opportunities must be carriedout in a systematic manner so that it can be shown that the initiatives proposed are thosewhich will yield the greatest benefits.Major opportunities will arise during the planning of new buildings, where theincremental cost of high efficiency equipment will be easy to determine, the lifetime willbe longest and there will be no, or little, difference in installation costs.MotorsSince its invention in the 1880s, the electric motor has had a long history ofdevelopment, with early efforts aimed at improving power and torque and reducing cost.It is only more recently (1970s according to the CDA UK) that the need for higherefficiency became apparent.Most motors operate at less than their design loading. It is important that high-efficiencymotors retain their energy efficiency at these loads. The justification for the initialpremium is simple: an electric motor can consume electricity to the equivalent of itscapital cost within the first 500 hours of operation-a mere three weeks of continuous use.The lifetime cost of losses is several times the purchase price of the motor.Clearly the lowest overall cost will not be achieved unless both capital and running costsare considered together.More about motorsPower CablesWhile the installation and use of improved energy-efficient equipment isunderway, the energy losses in undersized power cables are frequently ignored. Highconductivity copper is usually efficient enough to significantly reduce losses, howeverattention must be paid to the cables’ function and purpose. If cables are installed with aconductor size that is the minimum permissible to avoid overheating, energy losses canbe very significant.In a medium voltage power cable, the cost of losses over the lifetime of the equipmentcan be 10 times higher than the initial purchase cost, including installation.If the energy demand of a system subsequently increases to a level above the safe cablerating, the installation of extra power cables can be a significant expense. The initialspecification of cables that are an optimum economic size is therefore a recommendedpractice, notably encouraged by an IEC Standard.TransformersTransformers are among the most efficient machines ever designed bymankind, and are usually built of copper or aluminum. As copper has a conductivityalmost twice that of aluminum, it is often preferred in transformer construction. Thelargest power transformers have efficiencies at full load of 99.75%. Distribution copper-based transformers are smaller, less efficient and more lightly loaded. Transformers inurban distribution (typically 250-1,000kVa) may lose 1-2% of energy transformed asheat. For smaller transformers in rural areas (50-100kVa), efficiency in operation can beas low as 95%.In a constantly developing environment, energy consumption is an issue to be urgentlydealt with. In EU, over 4 million distribution transformers have been installed, i.e. 1 unitfor every 80 citizens. It takes 7-8 of the largest nuclear power stations to compensate the
energy losses in these transformers. All the wind-turbine capacity that has been installedin the year 2000 covers only 10% of these losses in distribution transformers.Clearly, energy efficiency in distribution transformers is a key factor in sustainableelectrification.ElectricalCopper is the standard benchmark for electrical conductivity. It conducts electricalcurrent better than any other metal except silver.Copper is routinely refined to 99.98% purity (even more pure than Ivory Soap) before itis acceptable for many electrical applications.Number 12 (AWG) copper wire is the most common size used for branch circuit wiringin buildings. The amount of copper products consumed in the U.S.A. this past year wouldmake a size 12 wire that could encircle the Earth 2,630 times or make 140 round trips tothe Moon.CDAs Electrical Energy Efficiency program illustrates how a simple upsizing of copperconductors used for electrical distribution can earn significant paybacks to buildingowners, usually within one to two years or less.Installing #10 AWG wire instead of #12 AWG for feeding a 15-amp lighting loadrunning half time (4000 hours per year) pays back the difference for its higher cost inonly 9 months, at $0.075 per kilowatt-hour (kWh).Because half of all the electricity generated in the U.S. is consumed by motor-drivensystems, the most significant energy savings are realized by upgrading systems withhigh-efficiency motors.A high-efficiency 3-hp motor operating full time at $0.08 per kWh would repay its costpremium in less than 5 months, and from then on save money and electricity.Premium motors are not only more efficient (mostly because they are made with morecopper), they also last much longer and generate less heat.Wherever electricity flows, connectors are required. Copper in its many varieties is thedominant and favored material whether conductors are used for high-current powerdistribution or "signal" level currents used for data and telecommunications.Some high-power connectors weigh in at 20 pounds or more, while tiny electronicconnectors may weigh as little as a few milligrams with spacing between pins less thanhalf a millimeter. The United States is the worlds leader in the multibillion-dollarconnector industry.A consortium assembled by the Copper Development Association is working on a projectto develop die materials for use in casting copper motor rotors. Such rotors would
dramatically increase motor efficiency. Commercialization of the process is expected in2002.Power quality problems that plague many modern offices and factories are largelypreventable. Copper-intensive solutions include using larger neutral conductors to handleharmonic loads, better grounding systems to dissipate transients and lightning, and feweroutlets per circuit to lessen interaction between office equipment and computers.Scores of lives and billions of dollars in property could be saved each year if buildingswere properly protected against lightning. A single lighting strike at a commercial facilitycould cause thousands of dollars per hour in lost production.Copper and its alloys are the most common and most effective materials used in lightningprotection.Nearly 50 tons of high conductivity, oxygen free copper wire was used to make 1,700super conducting electromagnets for a collider at the Brookhaven National Laboratory inNew York. The magnets are used in the 2.4-mile diameter underground collider to studysubatomic particles.