The Advanced Cables and Conductors program supports activities in next-generation cables and conductors to increase the delivery capacity of electricity systems, to improve the affordability of electric services by reducing the need for new rights-of-way, and to enhance efficiency by reducing energy losses. The Advanced Cables and Conductors Program has supported research in two areas; High Temperature Superconductivity and Advanced Conductors and High Temperature Superconductivity (HTS).
Twentieth-century power system components were based on traditional conductors using copper and aluminum wires. The opportunity now exists to modernize and expand the Nation’s electricity delivery system with equipment using an emerging new capability: practical high temperature superconducting (HTS) wires that have 100 times the capacity of conventional wires without energy loss due to electrical resistance. One of the challenges with this technology has been to develop economic processing methods for manufacturing ductile wires while using ceramic materials that are characteristically brittle and granular.
HTS technology has been applied to the key aspects of the electricity system—generation, delivery and control. For example, higher capacity HTS power lines could provide a new approach to building transmission and distribution systems that will reduce the footprint and allow additional capacity to be placed in service within existing rights-of-way. When cooled to and operated at liquid nitrogen temperature (77K or -1960C), HTS power equipment offers a new generation of reliable grid equipment with typically twice the capacity of same-sized conventional equipment with only half the energy losses. HTS Fault current limiters (FCLs) have the potential to save utilities money and make the modern grid more efficient by protecting electric grid equipment from damages and by helping to avoid outages. This added level of protection may, in turn, allow connectivity between power substations to increase grid flexibility and flow control.
The U.S. Department of Energy (DOE) led the national effort for development of high temperature superconductivity (HTS) wires and HTS electric equipment prototypes. Public-private collaborations, encouraged by the Department of Energy, have achieved world-record performance in HTS wires and are now delivering electricity to customers through HTS power cables. However, to reach their full potential, HTS equipment will require the capability to operate over a wide range of voltage and power, as our current electricity system does.
HTS technologies depend on high-performance, ultra-reliable refrigeration systems. DOE activities have also focused on improving cryogenic refrigeration systems and long cable housing to achieve cost, efficiency, and reliability targets.
DOE investments in HTS helped accelerate technology development in this high-risk, high-return area.
Advanced Conductors Research
The Advanced Conductors Research effort supports the development of technologies that will increase the current-carrying capacity of transmission cables and systems and provide relief in highly congested constrained corridors, thus increasing reliability systemwide.
Overhead power transmission lines frequently operate above their designed operating temperatures, which leads to sagging and also accelerates the degradation of components, thus increasing the risk of power outages due to equipment failure. The splices connecting the conductor lines are literally the weak links in power transmission systems. The Department of Energy is funding research to predict and enhance the service life of conductor-connector systems, which will enable increased performance and integrity of power line systems, thus increasing reliability of the overall electricity delivery system.
Another group of technologies under development with Department of Energy funding are superhydrophobic coatings for transmission lines. Hydrophobicity, literally “water-fearing”, is a property of some materials to repel water particularly well. The accumulation of ice on transmission lines is the cause of numerous power outage events every year. By applying superhydrophobic coating to transmission lines, there should be fewer outages due to ice-related events. In addition, superhydrophobic coatings may be applied to structural components in electricity transmission network to prevent corrosion, thereby increases reliability and reduces maintenance costs.
- Peer Review
- R&D 100 Awards
- Los Alamos National Lab
- Oak Ridge National Lab
- Superconductivity News Update
Fact Sheets and Reports
- Superconductivity Program Overview (July 2009)
- HTS Cable Project Overview (July 2009)
- Albany Cable Project
- Columbus Cable Project
- LIPA Cable Project
- Fault Current Limiter Fact Sheet (November 2009)
- An Assessment of Fault Current Limiter Testing Requirements (February 2009)
2010 Advanced Cables and Conductors Peer Review
The Superconductivity Program was involved in a number of Superconductivity projects and demonstrations throughout the U.S. with manufacturers, laboratories, utilities, universities, and several states.
The Superconductivity Program held a series of successful wire workshops to advance the research and development of coated conductors. Presentations from the 2007, 2006, and 2005 workshops are available.