Renewable energy (RE) and energy storage are two families of technology that seek to reduce carbon emissions and fossil fuel dependence. To better understand the role of copper in renewables and energy storage, the Copper Development Association (CDA) commissioned two studies, which not only examine copper’s function but also provide insights into energy infrastructures.
The first is by BBF Associates and titled “Current and Projected Wind and Solar Renewable Electric Generating Capacity and Resulting Copper Demand.” The second is a KEMA study titled “Market Evaluation for Energy Storage in the United States,” which is now available online.
Renewable Energy
The renewable energy study pays particular attention to copper usages in the generation of electricity from wind energy, including both offshore and land-based installations. 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 sources than for fossil fuels or nuclear.
Copper usage intensity for renewables is high because solar panels and wind turbines are spread over large land areas. Once installed, of course, copper is not consumed like a fuel but rather performs its functions for many years and ultimately is recyclable.
The study found copper usage intensity for offshore wind-energy at approximately 21,000 pounds of copper per megawatt; for land-based wind energy, it is approximately 5,600 to 14,900 pounds per megawatt, similar to the 5,400 to 15,400 pounds per megawatt used for photovoltaic solar installations. The large spread is attributable to the difference between copper- and aluminum-wound step-up transformers.
Copper usage intensity in land-based wind farms is strongly correlated to the physical size of the installation due to the miles of copper grounding cable and copper-concentric-neutral aluminum-conductor power cable installed over large distances.
Other important contributors to copper intensity include magnet wire for generators and transformers, DLO cables, control and communication cables, and bus bar for switchgear. (“DLO” is a designation for “diesel locomotive cables,” which last longer in difficult operating environments than other cables.)
Wind farm designs have become somewhat more uniform than in early years, and it has become an accepted practice to install a single all-copper grounding system connecting all components (turbines, transformers, substations, etc.).
Grounding conductors are usually boast an American wire gauge rating of 4/0 but may be as large as 250 thousands of circular mils. A survey of more than 100 wind farms revealed that conductor lengths average 25 miles per 100-megawatt wind farm.
The study also revealed that the cost of wind energy may decrease as turbine size increases to five megawatts and larger. Technological advances in wind include direct-drive systems that eliminate trouble-prone gearboxes, and electrical innovations such as high-frequency power conditioning in the nacelle to ensure optimum grid compatibility.
Long-term Projections
The United States is one of the largest, fastest growing markets for wind power development in the world. At the close of 2011, the United States. had an installed capacity of about 47 gigawatts; it added more than 13 gigawatts in 2012, bringing the total to more than 60 gigawatts, which compares to a world total of 282 gigawatts, according to recent statistics from the Global Wind Energy Council.
Not counting offshore wind farm development and using United States. Energy Information Administration projections, the BBF study estimates new markets for copper from renewable energy at 153 to 414 million pounds by 2020; and 202 to 539 million pounds by 2035.
Realizing the goal of 20 percent RE by 2030 in the U.S. would require more than 300 gigawatts, a 15 percent compound annual growth rate over 25 years and a $60 billion investment in transmission. Based on the U.S. Department of Energy’s “20 percent by 2030” goal, annual demand for copper in renewable plants of all types is projected at 108 million to 306 million pounds, assuming offshore wind farms of 100 MW per year are reached by 2020 and 1 gigawatt per year thereafter.
Market Factors for RE
The anticipated expiration of the federal production tax credit (PTC) contributed to the growth of new installations in the United States in 2012. A hiatus in the credit in 2009 immediately brought about a 50 percent drop in new RE development until the credit was re-established. Recently, the federal PTC was extended through 2013.
The currently low cost of natural gas has also hindered acceptance of new RE facilities since new gas-fired generation is also perceived as environmentally “clean.”
The increasing emphasis on efficiency and reliability presents an opportunity to bring information about copper’s advantages to RE equipment suppliers, RE-farm developers and, especially, prospective owners.
Energy Storage
According to the KEMA energy storage study, the U.S. energy storage market is robust and offers tremendous potential for growth over the next five years as well as associated copper demand in storage applications.
Thermal energy storage, pumped hydro power, compressed air energy storage (CAES) and distributed applications currently constitute the majority of the energy storage market and are used to support the integration of renewables, such as wind power and solar photovoltaics.
The market drivers for energy storage are energy independence and security; smart grid investments; time of use/peak demand rates; increase in renewables and distributed generation; and government policies, incentives and regulations.
Although all sectors of the energy storage market show strong potential, the greatest near-term growth potential from an application perspective is shown by distributed generation devices, renewable systems and ancillary services. Global opportunity over the next 10 to 20 years is estimated at upwards of 300 gigawatts in size, which translates into $200 billion to $600 billion in value.
Copper’s superior conductivity and reliability play a key role in the batteries, wiring and motors used by these devices. Lithium-ion, flow and sodium batteries as well as flywheels, CAES and pumped hydropower are strong users of copper at the unit level. Moreover, certain pieces of electrical equipment and supporting infrastructure – such as transformers, generators, inverters, cooling systems, other motors and wiring – rely on copper for efficient, reliable operation.
An Enabling Element
Copper is an “enabling element” because it allows for the collection of electrical energy from broadly dispersed energy sources while minimizing electrical losses.
The usage of copper in renewable energy and energy storage is an investment in a sustainable infrastructure and a sustainable future. Copper is one of the greenest metals on the planet when it is used in this manner.
Natural gas, coal and nuclear compete aggressively with RE but RE 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 dramatically. Furthermore, the KEMA study emphasizes growth in energy storage and supports our belief that copper is a key component in energy storage and renewable energy.
In this time of transformation of the electric grid, we encourage policy makers to support the growth of renewable energy and energy storage as sustainable technologies that provide reliability to the grid.
Zolaikha Strong is director of sustainable energy for the The Copper Development Association Inc. (CDA). CDA is a U.S-based, not-for-profit association of the global copper industry, influencing the use of copper and copper alloys through research, development and education, as well as technical and end-user support. For more information about CDA and to read both studies in their entirety, visit www.copper.org.
