The burned wire nuts, just above the sliprings, fasten aluminum wires. However, the undersized wire, possibly selected to cut costs, was not able to carry to the generated current as well as copper wire would have. (Photo credit: Joe Smith / National Renewable Energy Laboratory (NREL))
Copper-usage intensity is a measure of the pounds of copper necessary to install one megawatt of new power generating capacity. It is typically four to six times higher for renewable energy (RE) sources than for fossil fuels or nuclear. Wind turbines use copper in coil windings, in stator and rotor portions of the generator, high-voltage power cable conductors, transformer coils, and wind farm electrical-grounding systems. Some estimate that a 660-kW turbine holds 800 lbs. of copper.
Wind turbines use copper in coil windings, in stator and rotor portions of the generator, high-voltage power cable conductors, transformer coils, and the wind farm’s electrical grounding systems. (Photo credit: Copper Development Association)
Zolaikha Strong, Director of Sustainable Energy for the Copper Development Association (CDA) (www.copper.org), explains, “Copper-usage intensity for renewables is high because wind turbines are spread over large areas. Once installed, of course, copper is not consumed like a fuel but rather performs its functions for many years and ultimately is recyclable.” Copper is an “enabling element” because it permits the collection of electrical energy from broadly dispersed energy sources while minimizing electrical losses, says Strong.
To better understand the market for copper, the CDA commissioned a study titled “Current and Projected Wind and Solar Renewable Electric Generating Capacity and Resulting Copper Demand,” which is available online. The study pays particular attention to copper usage in the generation of electricity from wind power, including offshore and land-based installations.
The study estimates the copper-usage intensity for offshore wind-energy at about 21,000 lbs. per megawatt. For land-based wind, it is about 5,600 to 14,900 lbs. per megawatt, similar to the 5,400 to 15,400 lbs. per megawatt used for photovoltaic solar installations. The large spread is attributable to the difference between copper and aluminum-wound step-up transformers.
The role of government incentives
According to the Energy Information Administration’s (EIA) Annual Energy Outlook 2011, growth of the U.S. RE industry is currently driven by Federal tax incentives and state RE portfolios. In place in 29 states, the portfolios mandate the minimum RE fraction of total capacity. Additional drivers, not cited by the EIA, include the perception that RE reduces dependence on imported fuels and the fact that it improves atmospheric quality. EIA estimates that RE will dominate new electric generation build-outs until 2016-2020.
Unless Congress extends the Federal production tax credit, it will expire at the end of 2012. The RE industry is vulnerable to a discontinuance of this tax credit as well as the price of natural gas, which is currently low due to the recent discovery of large domestic reserves.
The map shows renewable portfolios and state incentives for renewable energy sources in the U.S. (Photo credit: U.S. Department of Energy: Database of Sustainable Incentives for Renewables and Efficiency (DSIRE))
Long-term projections
In May 2011, the U.S. ranked third in wind-energy at 40 GW. Globally, wind energy was at 200 GW as of 2010. Not counting offshore wind farm development and using U.S. EIA projections, the study estimates new markets for copper from RE at 153 to 414 million lbs. by 2020, and 202 to 539 million lbs. by 2035.
Realizing the goal of 20% RE by 2030 in U.S. would require more than 300 GW, that is 15% compounded annual growth rate over 25 years and a $60 billion investment in transmission. Based on the DOE’s “20% by 2030” goal, annual demand for copper in renewable plants of all types is projected at 108 million to 306 million lbs., assuming offshore wind farms of 100 MW per year by 2020, and 1 GW per year thereafter.
Natural gas, coal, and nuclear compete aggressively with RE sources, but wind is becoming more competitive as the industry successfully addresses three issues: RE equipment costs are falling, economies of scale are developing, and reliability is improving significantly.
“The usage of copper in wind is an investment in a sustainable infrastructure and a sustainable future. Copper is one of greenest metals on the planet when it is used in this manner,” says Strong. Copper’s conductivity and durability help make wind energy generation efficient and reliable. WPE
LINK TO THE STUDY: http://www.copper.org/about/pressreleases/pdfs/wind_solar_study.pdf
Richard E. deFay
Project Manager, Sustainable Energy
Copper Development Association
Filed Under: News, Uncategorized
