While superconducting wire is extremely high performance when compared to existing solutions, the best in class performance of Conductus® wire enables device manufactures to optimize design, maximize performance and reduce the number of wires necessary per device. Conductus® typical specifications:
Superconducting wire has traditionally been utilized in devices that are less cost sensitive and highly focused on proof of concept or high performance. This is anticipated to change as the improved economics of Conductus® wire enables the commercialization of new devices that are high performance as well as economical over conventional copper based solutions. The key factors in Conductus® wire’s cost benefits are:
Commercial Scale and Kilometer Capacity
Unlike Low Temperature Superconducting (LTS) wire that is commercially available with production in the hundreds of thousands of kilometers on an annual basis, High Temperature Superconducting (HTS) wire production remains limited and is not in supply in commercial volumes. STI is in the process of scaling capacity to commercialize our Conductus® wire. Our initial production machines have been installed in Austin, TX, with the final RCE-CDR production system, capable of 1km lengths.
The Conductus® Superconducting Wire Manufacturing Process Explained
Conductus® superconducting wire manufacturing approach utilizes simplified, layered wire architecture, designed to scale with high yield and commercial volumes. Conductus wire architecture consists of three key manufacturing processes. First, a commercial-grade stainless steel or hastelloy template is passed through an E-Polish process. Second, the template proceeds through an Ion Beam Assisted Deposition (IBAD) process in order to produce a template with the right surface conditions. Third, the High-Temperature Superconducting (HTS) materials are deposited onto the template using Conductus proprietary Reactive Co-evaporation Cyclic Deposition and Reaction (RCE-CDR) HTS deposition. As a final step, outside of the key manufacturing processes, a customer can request metal cap layers that cover the entire surface of the wire.
1. Electropolishing – or E-Polish
Electropolishing is an electrochemical process that removes a thin layer of C-276, reducing the surface roughness by leveling micro-peaks and valleys, thus improving the surface finish.
2. Ion Beam Assisted Deposition - IBAD
The IBAD process deposits perfectly oriented cubic oxides onto the SDP-coated substrates by means of energetic plasma that simultaneously deposits and etches away unwanted materials, leaving only a correct alignment of atoms on the substrate surface for the superconducting film growth. After completion of this step, the metal foil substrate is called a ‘template’ for superconductor film deposition.
3. Reactive Co-evaporation and Cyclic Deposition Reaction - RCE-CDR
The RCE-CDR process grows a Rare Earth, Barium, Copper Oxide (ReBCO) superconductor film onto the flexible template produced in the IBAD processes. This process is complex, requiring accurate temperature, uniform pressure, precise ratios of elements and the presence of oxidizing atmospheres to grow high-performance superconducting materials. The RCE-CDR system is scaled for large batch operation to ensure every portion of superconducting wire has uniform material properties. STI’s RCE-CDR process yields very high-quality superconducting wire to maximize current carrying performance.
Using a standardized foil slitting technique, customers can request a variety of widths for their specific applications.
4. Finishing & Shipping
Subsequent to the RCE-CDR superconducting growth, a cap layer of silver (or copper depending on the application) of 1-50µm is applied in-situ to protect the wire. In some applications, additional cap layers may be added, including copper, silver or brass. All superconducting wire manufactured by STI is qualified for current-carrying uniformity, homogeneity, and specified mechanical properties. The powerful combination of the IBAD & RCE-CDR processes gives STI the ability to manufacture high-quality superconducting wire with a simple and scalable technique.
Conventional electrical equipment is limited by the performance of traditional copper and aluminum conductors. Existing electrical motors, generators, transformers, transmission cables and current limiters typically are built with copper-based conductors, utilizing 100’s to 1000’s of strands of wire. As the power requirement increases so does the quantity of the conductor, which in turn increased the system size and weight until ultimately it becomes impractical to build. Copper-based conductors are also inefficient. The U.S. Department of Energy (DOE) estimates that U.S.-wide transmission and distribution losses increased from about 5% in 1970 to 9.5% in 2001 due to higher utilization, heavier congestion, inefficiency and overall equipment failure that resulted in power outages and power quality disturbances. This costs the U.S. economy in excess of $25 billion annually.
Copper wire has less than 1% of the power density of our typical Conductus® wire. This 100 times or more increase in power density reduces the physical number of wire strands required per device; resulting in a significant reduction in size and weight. Conductus® wire also addresses the problem of efficiency by all but eliminating electrical resistance. Devices made with Conductus® wire are extremely efficient providing reduced cost of ownership.
Advanced transmission and distribution technologies are necessary to enhance Smart Grid efficiency, real-time management, throughput and reliability. Existing copper-based systems are prime targets for change through disruptive technology. New superconducting electrical devices, built utilizing Conductus® high efficiency wire, are well positioned to address this challenge.
Conductus® - For Utilities and Smart Grids
The electric power industry is facing many challenges that threaten a utilities’ ability to deliver reliable and cost efficient power. These challenges include integration of renewable electricity, need for improved network efficiency, aging infrastructure, increased electrical demand and implementation of new Smart Grid technologies. Existing copper-based electrical conductors are inherently inefficient and cannot support the growing energy demand or Smart Grid infrastructure, making them prime targets for change through disruptive technology. At the heart of these NEW, adaptive, rapid-response networks is the need for advanced electrical conductors to transform the conventional, linear power architecture into a distributed, mesh infrastructure.
New, emerging, cost effective, high performance superconducting technologies provide unique benefits targeting Smart Grid infrastructure and offer an excellent alternative to conventional, copper-based solutions. Advanced, high power superconducting transmission cables and superconducting fault current limiters (SFCL) are game changing solutions with significant advantages. High power superconducting transmission cables improve total power by reducing voltage and increasing current; this reduces right-of-way, civil work and environment impact. SFCLs protect the grid from damaging faults, and enable power sharing between substations and connectivity to new sources of renewable power. These novel superconducting solutions are all made possible with superconducting wire. Superconducting solutions like SFCLs or superconducting cables are composed of 100s of superconducting wire strands ranging from 3 meters to 1000 meters in length. STI is collaborating with industry-leading, global electric utilities and device manufacturers to commercialize our best-in-class Conductus® superconducting wire for deployment.
The Power Problem
In short, central power generation stations (i.e. nuclear, natural gas power plants) push high power current (500 to 3,000 Megawatts) through transmission lines (i.e. high power cables) to substations. Substations step down power to medium voltage via transformers and redistribute power to end users (i.e. residential, commercial, government and industrial customers).
This conventional grid layout is a highly centralized network. Centralized power system are vulnerable to costly down-time; one downed power line could potentially result in widespread blackouts costing businesses and taxpayers billions of dollars.
As demographic growth and consumer adoption of electronic devices drives increased per capita electricity demand, the aging grid infrastructure will likely exhibit lower stability and reliability if government and utilities do not implement much needed infrastructure upgrades.
Another major issue facing the worldwide electric grid is the addition of renewable energy generation sources. Existing power generation sources like nuclear or coal plants provide a consistent and reliable flow of energy to the grid. The grid then tries to distribute a level quality of power to all areas. However, new alternative power sources like wind and solar energy, even if efficient and sustainable, provide intermittent and varying amounts of electricity to the grid. Power levels fluctuate based on time of day for solar power and change in wind speeds for wind power. This variable output of power creates massive energy storage issues that the grid cannot tolerate. Growth in the renewable energy sector, like solar, wind and electric vehicles, require Smart Grid improvement for success. Technology advancements in energy distribution and transmission will drive down cost and improve efficiency. Lastly, future power demand could greatly exceed power generation. Much infrastructure investment is required to ensure future power stability.
The Smart Grid Alternative
The Smart Grid is a completely new design concept utilizing a “mesh” as opposed to a linear structure. The goal is to transform the grid infrastructure into a distributed, de-centralized Smart Grid with redundant, dynamic self-healing nodes that can reroute power in the event of a major grid disruption and redistribute power real-time to areas of need. The Smart Grid is also an electrical grid that monitors and adjusts based on information received from the suppliers and consumers of electricity. This new automated approach will improve the efficiency, reliability, economics and sustainability of the production and distribution of electricity. At the heart of this new adaptive rapid response grid is the need for a conductor that will enable a distributed architecture.
Advanced transmission and distribution technologies are necessary to enhance Smart Grid efficiency, real-time management, throughput and reliability. Existing copper-based systems are prime targets for change through disruptive technology. New, emerging, low cost, high performance superconducting technologies have become an alternative to conventional copper-based solutions by providing unique benefits targeting Smart Grid infrastructure improvement.