Renewable energy sources such as solar , wind , tidal , hydro , biomass , and geothermal have become significant sectors of the energy market.   The rapid growth of These sources in the 21st century has-been Prompted by Increasing costs of fossil fuels as well as Their negative environmental impacts. While the average capacity of renewable energy sources was only 7% globally in 2010, Few new facilities were from fossil fuel-based power plants. The trend Towards new power capacity by renewables is expected to continue through 2020.  Since renewable energy supplies offset the amount of fossil fuels That need to be combusted in power plants , the use of renewables Indirectly helps to Reduce CO 2 Emissions . Hence, renewable energy supplies enable societies to progress towards lower-carbon-based economies.
Copper plays an important role in renewable energy systems.     Since copper is an excellent thermal and electrical conductor among the engineering metals (second only to silver),  power systems environmental impacts. By using copper instead of other lower electrical energy-efficient metal conductors, less electricity needs to be generated to satisfy a demand power demand.
This article discusses the role of copper in various renewable energy generation systems.
Overview of copper use in renewable energy generation
Copper plays a larger role in renewable energy generation than in conventional power plants , in terms of tonnage of copper per unit of installed power. While conventional power requires Approximately 1 ton of copper per installed megawatt (MW) renewable technologies as wind and solar Such require four times more copper per installed MW.  
Wind and solar photovoltaic energy systems have the highest carbon content of all renewable energy technologies. Wind power and photovoltaic power are the fastest growing renewable-based markets. Significant growth is also expected in thermal concentrating solar power. 
The total amount of copper used in renewable and distributed electricity generation was estimated to be 272 kilotonnes (kt). Cumulative copper use through 2011 was estimated to be 1,071 kt.
|Installed power in 2011 ||Cumulative installed power to 2011 ||Copper use in 2011   ||Cumulative copper use to 2011   |
|Gigawatts (GW)||Gigawatts (GW)||Kilotons (kt)||Kilotons (kt)|
|Solar thermal electricity||0.46||1.76||2||7|
|Total for all three technologies||272||1071|
Copper conductors are used in major electrical renewable energy components, such as turbines , generators , transformers , inverters , electrical cables , power electronics , and information cable. Copper use is the same in turbines / generators, transformers / inverters, and cables. Much less copper is used in power electronics.
Solar thermal heating and cooling energy systems rely on copper for their thermal energy efficiency benefits. Copper is also used as a special corrosion-resistant material in renewable energy systems in wet, humid , and corrosive saline environments.
Solar photovoltaic power generation
The Sun delivers almost 4 million exajoules (EJ) of energy to the Earth.  Various technologies are being developed to exploit this huge energy source.
Solar photovoltaics (PV) is an important but still evolving technology that harnesses the Sun’s power to generate electricity. As sunlight hits a photovoltaic cell , it frees and stirs up electrons , which then collects on conductive plates to create electricity.
Of the 20,000 TWh of power consumed globally in a single year,  approximately 90 TWh are generated from solar PV systems. While this is only a very small percentage of overall energy consumption (0.6% of total installed Electricity Generating capacity worldwide),  it is nevertheless Sufficient to power the needs of more than 10 million people living at the standard of living in a Developed country.
Various overlapping statistics concerning the growth of solar PVs have been cited. Solar PVs have been cited to have a 40% annual growth rate, which may grow even faster as the cost of technology continues to decline. Another source cites operating capacity increased by an average of 58% annually from year end-2006 through 2011.  Installed capacity estimates to 2020 2010 and 2020. 
Household PV systems are smaller and smaller in power transmission and distribution than in large-scaled PV power stations. Households are able to generate their own electricity and use the grid for support and reliability.
For these reasons, policy initiatives are taking place to enhance the deployment of solar photovoltaic energy installations. This would boost the steady expansion of PV markets by reducing the competitiveness of PVs compared to fossil fuel technologies.  The goal at this point is to reach grid parity,  where the cost of generating energy from rooftop panels over the course of their 25-year lifetime equates to the cost of retail electricity. This achievement has already been accomplished in some regions.  
Copper in photovoltaic power systems
The use of copper in photovoltaic systems is substantial, averaging around 4-5 tonnes per MW or higher if ribbons (conductive strips to connect individual PV cells) are considered.  Copper is used in: 1) small wires that interconnect photovoltaic modules ; 2) earthing grids in electrode earth pegs, horizontal plates, naked cables, and wires; 3) DC cables that connect photovoltaic modules to inverters ; 4) low-voltage AC cables that connect inverters to metering systems and protection cabinets; 5) high-voltage AC cables; 6) communication cables; 7) inverters / power electronics; 8) ribbons; and 9) transform windings.
Copper used in photovoltaic systems in 2011 was estimated to be 150 kt. Cumulative copper use in photovoltaic systems was estimated to be 350 kt. 
Photovoltaic system configurations
Solar photovoltaic (PV) systems are highly scalable, ranging from small rooftop systems to large photovoltaic power stations with capacities of hundreds of megawatts . Residential and community-based systems generally range in capacity from 10 kW to 1 MW.
PV cells are grouped together in solar modules . These modules are connected to PV arrays. In grid-connected photovoltaic power system , arrays can form sub-fields from which electricity is collected and transported towards the grid connection.
Copper solar cables connect modules (cable module), arrays (array cable), and subfields (field cable). Whether a system is connected to the grid or not, electricity is being supplied from the DC to AC and stepped up in voltage. This is done by solar inverters which contains copper windings, as well as copper-containing power electronics.
The photovoltaic industry uses several different types of technologies for the production of solar cells and the second generation of technologies, while the third generation of technologies is still in development. Solar cells typically convert 20% of incident sunlight into electricity, allowing the generation of 100 – 150 kWh per square meter of panel per year. 
Conventional first-generation crystalline silicon (c-Si) technology includes monocrystalline silicon and polycrystalline silicon . In order to reduce costs of this wafer-based technology, copper-contact silicon solar cells are emerging as an important alternative to silver as the preferred conductor material. Challenges with solar cell metallization in the creation of a homogenous and qualitatively high-value layer between silicon and copper to serve as a barrier against copper diffusion into the semiconductor . Copper-based front-side metallization in silicon solar cells is a significant step towards lower cost. 
The second-generation technology includes thin film solar cells . DESPITE HAVING has Slightly lower conversion efficiency than conventional PV technology, the overall cost-per-watt is still lower. Commercially significant thin film technologies include copper indium gallium selenide solar cells (CIGS) and cadmium telluride photovoltaics (CdTe), while amorphous silicon (a-Si) and micromorphous silicon (m-Si) tandem cells are slowly being outcompeted in recent years.
CIGS, which is actually copper (indium-gallium) diselenide, or Cu (InGa) Se 2 , differs from silicon in that it is a heterojunction semiconductor . It has the highest solar energy conversion efficiency (~ 20%) among thin film materials.  Because CIGS strongly absorbs sunlight, a much thinner film is required than with other semiconductor materials.
A photovoltaic cell manufacturing process has made it possible to print CIGS semi-conductors. This technology has the potential to reduce the price per solar watt delivered.
While copper is one of the components in CIGS solar cells, the copper content of the cell is actually small: about 50 kg of copper per MW of capacity. 
Mono-dispersed copper sulphide nanocrystals are being researched as alternatives to photovoltaic devices. This technology, which is still in its infancy, has potential for dye-sensitized solar cells , all-inorganic solar cells, and hybrid nano-crystal- composite polymer solar cells. 
Solar generation systems cover large areas. There are many connections among modules and arrays, and connections between arrays in sub-fields and linkages to the network. Solar cables are used for wiring solar power plants.  The importance of these cables should not be underestimated.  The amount of cabling involved can be substantial. Typical diameters of copper cables are 4-6 mm 2 for cable module, 6-10 mm 2 for cable array, and 30-50 mm 2 for cable field. 
Energy efficiency and system design considerations
Energy efficiency and renewable energy are two pillars of a sustainable energy future. However, there is little linking of these pillars with their potential synergies. The most efficient energy services are delivered, the largest renewable energy can become an effective and significant contributor of primary energy. The more energy is obtained from renewable sources, the less fossil fuel energy is required to provide that same energy demand.  This linkage of renewable energy with energy efficiency is related to the electrical energy efficiency benefits of copper.
Increasing the diameter of a copper cable increases its electrical energy efficiency (see: Copper wire and cable ) . Thicker cables reduce resistive (I 2 R) loss , which affects lifetime profitability of PV system investments. Complex cost evaluations, factoring costs for materials, the amount of solar radiation to solar modules per year (accounting for annual and seasonal variations, subsidies, tariffs, payback periods, etc.) are justified.
Depending on circumstances, some conductors in PV systems can be specified with either copper or aluminum . As with other electrical conducting systems, there are advantages to each (see: Copper wire and cable ) . Copper is the preferred material when high electrical conductivity and flexibility of the cable are of paramount importance. Also, in the case of smaller cable trays, and when in steel or plastic pipes. 
Cable ducting is not needed in less than 25mm 2 . Without duct work, they are less expensive than aluminum. 
Data communications networks rely on copper, fiber optics , and / or radio links. Each material has its advantages and disadvantages. Copper is more reliable than radio links. Signal attenuation with copper wires and cables can be resolved with signal amplifiers . 
Concentrating solar thermal power
The sun’s solar energy can also be harnessed for its heat. When the Sun ‘s energy heats a fluid in a closed system, its pressure and temperature rise. When introduced to a turbine , the fluid expands, turning the turbine and producing electrical power . 
Concentrating solar power (CSP), Also Known As Thermal solar electricity (STE), uses arrays of mirrors That concentrate the sun’s rays to temperatures entre 400 0 C -1000 0 C.  Electrical power is Produced When the light is converted Concentrated to heat, which drives a heat engine (usually a steam turbine ) connected to an electrical power generator.
CSP facilities can produce large-scale power and hold much in areas with plenty of sunshine and clear skies. Poised to make Sun-powered grids a reality,  CSP is currently capable of providing power and dispatchability on a scale similar to that of fossil fuel or nuclear electrical power plants.
The electrical output of CSP facilities is changing when they are spreading. CSP offers the use of fuel, which can be used when required, allowing it to be used for base, shoulder and peak loads. 
These groups are estimated to be the most important in the world.  For this reason, plans for future CSP facilities are ambitious. A timeline of CSP’s deployment around the world is available.  Total installed power is forecasted to increase exponentially through 2025,   creating as much as 130,000 jobs. 
In 2010, Spain , the world leader in CSP technology, was constructing or planning to build 50 large CSP plants. That nation has a total installed base of 1581 MW of power plus an additional 774 MW nearing completion for installation.  Other countries in southern Europe also have CSP facilities, as do countries in Emerging Markets, Such As Chile , India , Morocco , Saudi Arabia , South Africa , and the United Arab Emirates .   
Unlike wind energy, photovoltaics, and more distributed power, the main advantage of CSP is its thermal storage capability  and hybridization possibilities.  Storage systems range from 4 hours in the most typical plants to 20 years when base load is required. This can complement other sources of power.
CSP systems are sometimes combined with fossil fueled steam turbine generation, but interest is growing in pure CSP technology.  Further information on concentrating solar power is available from the Global Solar Thermal Energy Council. 
Copper in concentrating thermal solar power facilities
A CSP system consists of: 1) a concentrator or collector containing mirrors that reflect solar radiation and deliver it to the receiver; 2) a receiver that absorbs concentrated sunlight and heat transfer to a working fluid (usually a mineral oil , or rarely, molten salts , metals , steam or air ); 3) a transport and storage system that passes the fluid from the receiver to the power conversion system; and 4) a steam turbine that converts thermal power to electricity on demand.
Copper is used in field power cables , grounding networks, and motors for tracking and pumping fluids, as well as in the main generator and high voltage transformers . Typically, there is about 200 tons copper for a 50 MW power plant. 
It has been estimated that it has been used in the past 20 years. 
There are several types of CSP technologies, such as parabolic trough seedlings, tower plants, distributed linear absorbing systems, linear linear Fresnel plants, and dish Stirling plants.  The use of copper in these plants is described here.
Parabolic trough plants
Parabolic trough plants are the most common CSP, representing about 94% of power installed in Spain. These plants collect solar energy in parabolic trough concentrators with linear collector tubes. The heat transfer fluid is generally used at temperatures ranging from 300 ° C to 400 ° C. The typical storage capacity of a 50 MW facility is 7 hours at nominal power. A plant of this size and storage capacity can generate 160 GWh / year in a region like Spain.
In parabolic trough plants, copper is specified in the collector field (power cables, signals, earthing, electrical motors); steam cycle (water pumps, condenser fans, cabling to consumption points, signal control and sensors, motors), electricity generators (alternator, transformer), and storage systems (circulating pumps, cabling to consumption points). A 50 MW plant with 7.5 hours of storage contains approximately 196 tonnes of copper, of which 131,500 kg are in cables and 64,700 kg are in various equipment (generators, transformers, mirrors, and motors). This translates to about 3.9 tonnes / MW, or, in other terms, 1.2 tonnes / GWh / year. A plant of the same size with less than 20% less copper in the solar field and 10% less in the electronic equipment.
Copper conditions also vary according to design. The solar field of a typical 50 MW power plant with 7 hours of storage capacity consists of 150 loops and 600 motors, while 100 loops and 400 motors. Motorized valves for mass flow control in the loops rely on more copper. Mirrors uses a small amount of copper to Provide galvanic corrosion protection to the reflective silver layer. Changes in the size of the seedlings, size of collectors, efficiencies of heat transfer fluids will also affect material volumes. 
Tower plants , also called central tower power plants, may become preferred CSP technology in the future. They collect solar energy by the heliostat field in a central receiver mounted at the top of the tower. Each heliostat tracks the Sun along two axes (azimuth and elevation). Therefore, two motors per unit are required.
Electricity generation (alternator, transformer) water pumps, condensing fans), cabling to consumption points, signal control and sensors, and motors.
A 50 MW solar tower facility with 7.5 hours of storage uses about 219 tons of copper. This translates to 4.4 tonnes of copper / MW, or, in other terms, 1.4 tonnes / GWh / year. Of this amount, cables account for approximately 154,720 kg. Electronic equipment, such as generators, transformers, and motors, account for 64.620 kg of copper. A 100 MW plant was slightly larger in the solar field because of the efficiency of the field diminishes with the size. A 100 MW plant will have less copper per MW in process equipment. 
Linear Fresnel plants
Linear Fresnel plants use linear reflectors to concentrate the Sun’s rays in an absorbent tube similar to parabolic trough plants. Since the concentration factor is less than in parabolic trough plants, the temperature of the heat transfer is lower. This is why MOST plants use saturated steam as the working fluid in Both the solar field and the turbine.
A 50 MW linear Fresnel power plant requires about 1,960 tracking motors. The power required for each motor is much lower than the parabolic trough plant. A 50 MW lineal Fresnel plant without storage will contain about 127 tons of copper. This translates to 2.6 tonnes of copper / MW, or 1.3 tonnes of copper / GWh / year. Of this amount, 69.960 kg of copper in the field, solar field, earthing and lightning protection and controls. Another 57,300 kg of copper is in equipment (transformers, generators, motors, mirrors, pumps, fans). 
Dish Stirling plants
These plants are an emerging technology that has a potential solution for decentralized applications. The technology does not require water for cooling in the conversion cycle. These plants are non-dispatchable. Energy production ceases when clouds pass overhead. Research is being conducted on advanced storage and hybridization systems.
The largest dish Sterling facility has a total power of 1.5 MW. Relatively more copper is needed in the field of CSP technologies because electricity is actually generated there. Based on existing 1.5 MW plants, the copper content is 4 tons / MW, or other, 2.2 tons of copper / GWh / year. A 1.5 MW power plant has some 6.060 kg of copper in cables, induction generators, drives, field and grid transformers, earthing and lightning protection. 
Solar water heaters [solar domestic hot water systems ]
Solar water heaters can be cost-effective way to generate hot water for homes. They can be used in any climate. The fuel they use, sunshine, is free. 
Solar hot water collectors are used by more than 200 million households worldwide.  The total installed capacity of solar thermal heating and cooling units in 2010 was 185 GW-thermal. 
GWth, excluding unglazed swimming pool heating. Most solar thermal energy is used for water heating, but is particularly important in Europe. 
There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which do not. Passive solar techniques do not require working electrical or mechanical elements. They include the design of materials, the design of natural materials, and the design of natural materials. 
Copper is an important component of solar thermal heating and cooling systems because of its high heat conductivity , resistance to atmospheric and water corrosion, sealing and joining by soldering, and mechanical strength. Copper is used in both primary and secondary circuits (pipes and heat exchangers for water tanks).  For the absorbing plate , aluminum is sometimes used when it is cheaper, yet when combined with piping, it can be used in the process. An alternative material that is currently used is PEX-AL-PEX But there may be similar problems with the heat transfer between the pipes and the pipes as well. One way around this is to use the same material for both the piping and the absorb plate. This material can also be used for copper PEX-AL-PEX.
Three types of solar thermal collectors are used for residential applications: flat collectors , integral collector-storage, and solar thermal collectors: Evacuated tube collectors ; They can be direct circulation (ie, indirect heat circulation, ie, pumps heat a transfer fluid through a heat exchanger, which then heats water that flows into the home) systems. 
In an evacuated tube solar hot water heater with an indirect circulation system, evacuated tubes Solar thermal energy is absorbed within the evacuated tubes and is converted into usable concentrated heat. Copper heat pipes transfer thermal energy from the solar tube into a copper header. A thermal transfer fluid (water or glycol mixture) is pumped through the copper header. As the solution circulates through the copper header, the temperature rises. The evacuated glass tubes have a double layer. The outer layer is fully transparent to allow solar energy to pass through unimpeded. The inner layer is treated with a selective optical coatingthat absorbs energy without reflection. The inner and outer layers are fused at the end, leaving an empty space between the inner and outer layers. All of the above is evacuation process, thus creating the thermos effect which stops conductive and convective transfer of heat that might otherwise escape into the atmosphere. Heat loss is further reduced by the low-emissivity of the glass that is used. Inside the glass tube is the copper heat pipe. It is a sealed hollow copper tube which contains a small amount of liquid property, which under low pressure boils at a very low temperature. Other components include a solar heat exchanger and a solar pumping station, with pumps and controllers.     
Wind power is the conversion of wind energy to a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, wind pumps for water pumping or drainage, or sails to propel ships. In a wind turbine , the wind’s kinetic energy is converted into mechanical energy to drive a generator , qui in turn Generates electricity .
Wind energy is one of the fastest growing energy technologies. GW in 1996 to around 160 GW in 2009.  GW in 2012. This was the largest addition in any of the renewable energy technologies.  It is anticipated that the growth of wind energy will continue to rise dramatically. Moderate estimates for global capacity by 2020 are 711 GW. 
Some 50 countries operated wind power facilities in 2010. 
Traditionally, wind power has been generated on land. But higher wind speeds are available offshore compared to land.  Technologies are being improved to exploit the potential of wind power in offshore environments. The offshore wind power market is expanding with the use of larger turbines and farther facilities from shore. 
Offshore installation, as yet, is a comparatively small market, probably accounting for a little more than 10% of installation globally. The location of new wind farms will be offshore, especially in Europe. Offshore wind farms are usually much larger, often with over 100 turbines with ratings up to 3 MW and above per turbine. The harsh environment means that the individual components need to be more rugged and corrosion protected than their onshore components. Increasingly long connections to shore with subsea MV and HV cables are required at this time. The need for corrosion protection favors copper nickel cladding as the preferred alloy for the towers.
Wind power installations vary in scale and type. Large wind farm facilities linked to the electrical grid are at one end of the spectrum. These may be located onshore or onshore gold. At the other end of the spectrum are small individual turbines that provide electricity to individual facilities or electricity-using facilities. These are often rural and grid-isolated sites. 
The basic components of a wind power system consists of a tower with rotating blades containing an electricity generator and a transformer to step up voltage for electricity transmission to a substation on the grid. Cabling and electronics are also important components.  
Copper in wind power generation
Copper is an important conductor in wind power generation.   Wind farms can hold several hundred-thousand feet of copper. 
It has been estimated that the amount of copper used for wind energy systems in 2011 was 120 kt. The cumulative amount of copper installed in 2011 was estimated to be 714 kt. 
Copper is Primarily used in coil windings in the stator and rotor portions of generators (qui convert mechanical energy into electrical energy), in low voltage cable conductors Including the vertical electrical cable That connects the nacelle to the base of the wind turbine , in the coils of transformers (which AC up high voltage AC up to voltage), and in gearboxes(which convert the slow revolutions per minute of the rotor blades to faster rpms). Copper may also be used in the nacelle, auxiliary motors, auxiliary motors, cooling circuits (cooling configuration for the entire drive train ), and power electronics (which enables the wind turbine systems to perform like a power plant). 
In the coils of wind generators, electric current suffers from losses that are proportional to the resistance of the wire that carries the current. This resistance, called copper losses , causes energy to be lost by heating up the wire. In wind power systems, this resistance can be reduced with thicker copper wire and a cooling system for the generator, if required. 
Copper in generators
The amount of copper in a generator will vary according to the type of generator, its power rating , and its configuration. The weight of copper has an almost linear relationship to the power rating of the generator. The average capacity of a wind generator installed in Europe was estimated to be 1.5 MW in 2004 and 2 MW in 2009. The average capacity is forecast to increase to 2.5 MW in 2015 and to 3 MW in 2020. 
Generators in direct-drive wind turbines contain more copper, the generator itself is bigger than the absence of a gearbox. 
A generator in a direct drive configuration could be 3.5 times to 6 times in a geared configuration, depending on the type of generator. 
Five different types of generator technologies are used in wind generation:
- double-fed asynchronous generators (DFAG)
- conventional asynchronous generators (CAG)
- synchronous generators (CSG)
- permanent magnet synchronous generators (PMSG)
- high-temperature superconductor generators (HTSG)
The amount of copper in these types of generator is here.
|Technology||Average copper content (kg / MW)||Notes|
|Double-fed asynchronous generator (DFAG)||650||Geared; most common wind generator in Europe (70% in 2009; strong demand until 2015, then it will be important to keep it in mind.|
|Conventional asynchronous generators (CAG)||390||Geared; neutral demand until 2015; will become negligible by 2020.|
|Conventional synchronous generators (CSG)||330-4000||Geared and direct; will become much more popular by 2020.|
|Permanent magnet synchronous generators(PMSG)||600-2150||Market expected to develop by 2015.|
|High-temperature superconductor generators(HTSG)||325||Nascent stage of development. It is expected that these machines will be more WTGs. Offshore could be the most suitable niche application.|
Direct-drive configurations of the synchronous type machines contain the most copper. Conventional synchronous generators (CSG) direct-drive machines have the highest per-unit copper content. The share of CSGs will increase from 2009 to 2020, especially for direct drive machines. DFAGs accounted for the most unit sales in 2009. 
The variation in the copper content of CSG generators depends on whether they are coupled with single-stage (heavier) or three-stage (lighter) gearboxes. Similarly, the difference in copper content in PMSG generators depends on whether turbines are medium speed, which are heavier, or high-speed turbines, which are lighter. 
There is increasing demand for synchronous machines and direct-drive configurations. CSG direct and geared DFAGs will lead the demand for copper. The highest growth in demand is expected from the PMSGs, which is forecast to account for 7.7% of the total demand for copper in wind power systems in 2015.
Hiring with high-speed turbulent winds are better suited for variable-speed wind turbine generators with full-scale power converters due to the greater reliability and availability they offer in such conditions. Of the variable-speed wind turbine options, PMSGs could be preferred over DFAGs in such locations. In conditions with low wind speeds and turbulence, DFAGs could be preferred to PMSGs. 
Generally, PMSGs deal better with grid-related faults and they could eventually offer higher efficiency, reliability, and availability than geared counterparts. This could be achieved by reducing the number of mechanical components in their design. Currently, however, the geared wind turbine generators have been more thoroughly field-tested and are more expensive produced. 
The current trend is for PMSG hybrid installations with a single-stage or two-stage gearbox. The most recent wind turbine generator by Vestas is geared drive. The most recent wind turbine generator by Siemens is a hybrid. Over the medium term, PMSG is expected to become more attractive.  High-temperature superconductors (HTSG) technology is currently under development. It is expected that these machines will be able to achieve more power than other wind turbine generators. If the offshore market is the most suitable niche for HTSGs. 
Copper in other components
For a 2 MW turbine system, the following amounts of copper are estimated for components other than the generator:
|Component||Average Cu content (kg)|
|Auxiliary motors (pitch and yaw drives)||75|
|Other parts of the basket||<50|
|Power electronics (converter)||150|
|Earthing and lightning protection||750|
Cabling is the second largest copper-containing component after the generator. A wind tower system with the transformer to the medium voltage (MV) power cables running from the top to the bottom of the tower, then to a collection of or direct to the substation. The tower assembly will have a strong connection to the system, while low-voltage (LV) power cables are required. 
For a 2 MW wind turbine, the vertical cable could range from 1,000-1,500 kg of copper, depending upon its type. Copper is the dominant material in underground cables. 
Copper in grounding systems
Copper is vital to the electrical grounding system for wind turbine farms. Turbine masts attract lightning strikes, so they require lightning protection systems. When lightning strikes a turbine blade, current passes along the blade, through the blade hub in the bucket ( gearbox/ generator enclosure) and down the mast to a grounding system. The blade incorporates a large cross-section of copper conductor that runs along its length and enables the flow of power. The nacelle is protected by a lightning conductor, often copper. The grounding system, at the base of the mast, consists of a thick copper ring conductor bonded to the base or located within a meter of the base. The ring is attached to two diametrically opposed points on the mast base. Copper leads extend outward from the ring and connect to copper grounding electrodes. The grounding rings on turbines on wind farms are inter-connected, providing a networked system with an extremely small aggregate resistance. 
Solid copper wire has been traditionally deployed for grounding and lightning equipment due to its excellent electrical conductivity . However, manufacturers are moving towards cheaper bi-metal copper clad or aluminum grounding wires and cables.  Copper-plating wire is being explored. Current disadvantages of copper plated wire include lower conductivity, size, weight, flexibility and current carrying capability.
Copper in other equipment
After generators and cable, the former amounts of copper are used in the remaining equipment. In yaw and pitch auxiliary motors, the yaw drive uses a combination of induction motors and multi-stage planetary gearboxes with minor amounts of copper. Power electronics have minimal amounts of copper compared to other equipment. As turbine capacity increase, converter ratings also increase from low voltage (<1kV) to medium voltage (1kV-5kV). Most wind turbines have full power converters , which have the same power rating as the generator, except the DFAG that has a power converter that is 30% of the rating of the generator. Finally, minor amounts of copper are used in air / oil and water cooled circuits on gearboxes or generators. 
Superconducting materials are being tested within and outside of wind turbines. They offer higher electrical efficiencies, the ability to carry higher currents, and lighter weights. These materials are, however, much more expensive than copper at this time. 
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- Jump up^ PV Technology: Swapping Silver for Copper, 2012. Renewable Energy World International; July 2, 2012; http://www.renewableenergyworld.com/rea/news/article/2012/07/pv-technology-swapping-silver-for-copper
- Jump up^ Characterization of 19.9% -Efficient CIGS Absorbers; National Renewable Energy Laboratory, May 2008; http://www.nrel.gov/docs/fy08osti/42539.pdf. Retrieved 10 February 2011
- Jump up^ Global Solar; http://www.globalsolar.com, cited in The Emerging Electrical Markets for Copper, Bloomsbury Minerals Economics Ltd., July 6, 2010; page 59. Independent research study available at Leonardo Energy – Ask an Expert; Archived copy . Archived from the original on 2012-11-26 . Retrieved 2012-12-12 .
- Jump up^ Wadia, C. and. al, 2008. Synthesis of copper (I) sulfide nanocrystals for photovoltaic application; Nanotech 2008 Conference Program Abstract; http://www.nsti.org/Nanotech2008/showabstract.html?absno=70355
- Jump up^ Solar First Source; Archived copy . Archived from the original on 2011-03-25 . Retrieved 2013-01-03 .
- Jump up^ Inverter and PV System Technology; Cables and Connectors; http://www.pv-system-tech.com/technology/cables-and-connectors
- Jump up^ Hutchinson, Alex, 2008. Solar thermal power can make sun-powered grid a reality; Popular Mechanics; November 1, 2008
- Jump up^ Technology Roadmap: Concentrating Solar Power; IEA,http://www.iea.org/publications/freepublications/publication/csp_roadmap.pdf
- Jump up^ Jha, Alok, 2009. Concentrated solar power could generate ‘quarter of world’s energy,’ The Guardian; May 26, 2009; https://www.theguardian.com/environment/2009/may/26/solarpower-renewableenergy
- Jump up^ 4 CSP facts and figures; Timeline of CSP deployment around the world; CSP World; Archived copy . Archived from the original on 2013-04-29. Retrieved 2013-04-22 .
- ^ Jump up to:a b Global Concentrated Solar Power Markets and Strategies: 2010-2025, IHS Emerging Energy Research, April 2010
- ^ Jump up to:a b c 2011 global status report by Renewable Energy Policy Network for the 21st Century (REN21)
- ^ Jump up to:a b Solar Thermal Power Market guide; Energy Business Reports; October 2011; 153 pps. Archived copy . Archived from the original on 2013-11-03 . Retrieved 2013-02-19 .
- Jump up^ CSP Markets Report 2012-2013; CSP Today; http://www.csptoday.com/csp-markets-report/conference-event-brochure.php
- Jump up^ Dessau, Kathy Li 2010. Concentrating solar thermal: Sun power even in the dark; Solar Novus Today; July 26; http://www.solarnovus.com/index.php?option=com_content&view=article&id=1073:concentrating-solar-thermal-sun-power-even-in-the-dark&catid=38:application-tech-features&Itemid=246
- Jump up^ Global Solar Energy Energy Council,http://www.solarthermalworld.com
- ^ Jump up to:a b Solar water heaters; Energy Savers; Energy Efficiency and Renewable Energy; US Department of Energy; http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=12850/
- Jump up^ PEX-AL-PEX frequently used for solar thermal collector construction
- Jump up^ Solar hot water; B & R Service Inc .; http://www.bandrservice.com/solar.htm
- Jump up^ How solar hot water system works; SolarPlusGreen.com; http://www.solarplusgreen.com/solar-know-how.htm
- Jump up^ Mirasol Solar Energy Systems; http://www.mirasolenergysystems.com/pdf/et-technology.pdf
- Jump up^ How solar heaters work; Mayca Solar Energy; Archived copy . Archived from the original on 2012-10-28 . Retrieved 2012-11-26 .
- Jump up^ Bayat Energy: solar water heaters; http://www.bayatenergy.co.uk/Solar%20Water%20Heaters%20Catalogue.pdf
- Jump up^ Wind Energy – The Facts, European Wind Energy Association (EWEA), cited in The Emerging Electrical Markets for Copper, Bloomsbury Minerals Economics Ltd., July 6, 2010
- Jump up^ Wind Power Offshore 2010 BTM Consult, Madsen & Krogsgaard; 22 November 2010. “Archived copy” . Archived from the original on 2011-06-30 . Retrieved 2010-11-22 .
- Jump up^ Distributed generation and renewables – wind power; Power Quality and Use Guide; Leonardo Energy; “Archived copy” (PDF) . Archived from the original (PDF) on 2012-11-01 . Retrieved 2012-12-12 .
- Jump up^ Miles of copper make it possible, Copper and Wind Energy: Partners for a Clean Environment; Copper Development Association Inc.,http://www.copper.org/applications/electrical/energy/casestudy/wind_energy_a6101.html#top
- ^ Jump up to:a b Wind energy basics – how copper helps make wind energy possible; http://www.copper.org/environment/green/casestudies/wind_energy/wind_energy.html
- Jump up^ Tatakis, Jim 2011. Copper truly is the green metal; Granite’s Edge – Investment Insight from Granite Investment Advisors; http://www.granitesedge.com/2011/02/01/copper-truly-is-the-green-metal
- Jump up^ Copper content assessment of wind turbines, Final Report V01, by Frost & Sullivan. Presented to ECI on July 12, 2010. Available at Leonardo Energy – Ask an Expert; Archived copy . Archived from the original on 2012-11-26 . Retrieved 2012-12-12 .
- Jump up^ Meyers, C. Bracken, 2009. Energy loss of a wind turbine; Centurion Energy; July 31, 2009; http://centurionenergy.net/energy-loss-of-a-wind-turbine
- ^ Jump up to:a b c d e f g h i Copper content assessment of wind turbines, Final Report V01, by Frost & Sullivan. Presented to ECI; July 12, 2010. Available at Leonardo Energy – Ask an Expert; Archived copy . Archived from the original on 2012-11-26 . Retrieved 2012-12-12 .
- Jump up^ Frost and Sullivan, 2009, cited in Wind Generator Technology, by Eclareon SL, Madrid, May 2012; www.eclareon.com; Available at Leonardo Energy – Ask an Expert; Archived copy . Archived from the original on 2012-11-26 . Retrieved 2012-12-12 .
- Jump up^ Mattera, Michael; 2010. An alternative to copper-based grounding; Windpoweer Engineering & Development; August 4, 2010; http://www.windpowerengineering.com/tag/copper-clad-steel/