Superconductivity as an Energy Carrier

1. i i Superconductivity as an Energy Carrier Conventional Gearbox 5 MW ~ 410 tons Conventional Gearless 6 MW ~ 500 tons HTS Gearless 8 MW ~ 480 ton (AMSC) with splay Center for Emergent Superconductivity Director : J.C. Davis 4A Lead Institution Partner Institutions Industry and University Affiliates Brookhaven National LaboratoryArgonne National Laboratory American Superconductor University of Illinois at Urbana-Champaign SuperPower / University of Houston pristine U(mV) H Electricity Grid Challenges 2nd Generation High Temperature Superconducting Wire Capacity, Transmission, Storage and Accommodating Renewables The grid faces fundamental challenges to meet the growing demand for electricity, 40% increase in the US and 100% in the world by 2035. Demand is exacerbated by electric cars, especially in urban areas where they will be popular and where present distribution is already approaching saturation. The rapid growth of renewable wind and solar electricity requires long distance transmission and seamless interconnection among the three national power grids. The variability of renewables requires storage of electricity on time scales of seconds, minutes and hours to accommodate fluctuations. Offshore wind, a steady and nearby resource, requires light weight, high capacity turbines. Cu shunt layer Ag cap layer YBCO superconductor LaMnO3 buffer Source: American Superconductor Because they generate little or no heat, 2nd generation coated conductors made from the 92 K superconductor YBa2Cu2O7 carry many times the current density of conventional copper wire. Cables wound from coated conductors carry up to 5 times the power of conventional copper cables in the same cross sectional area. MgO template Ni alloy substrate Al2O3 / Y2O3 Ni barrier Multilayer architecture of 2nd generation coated conductors. Only one layer, ~ 1 micron thick, is the superconductor. Superconductivity has solutions for all of these challenges. Superconducting Grid Solutions The grand scientific challenges for high temperature superconductor applications are to raise the magnitude and lower the anisotropy of the current carrying capability. Modular SMES Superconducting Magnetic Energy Storage The variability of wind and solar electricity requires storage for wide penetration 2.5 MJ Solar PV 3 60 MJ MW 2 Interstate Highway System for Electricity DC Superconducting Transmission Urban Power Delivery Long Island, NY 1 250 750 1250 Minutes since start of day • Electric currents can be stored and recovered quickly with little or no loss by ramping up and down a superconducting magnet. Technology Advances: • Ultra High Field (~ 24 T) magnet storage coil and Superconducting switch • 2G HTS wire with Ic > 600 A • Modular, scalable converter concept for direct connection to medium voltage grid with high round trip efficiency (> 85%) Ultra High Field SMES Benefits: • Fast dynamic response • Nearly infinite cycling • Magnetic energy ~ B2 • Size ~ R2, (~ R3 for batteries) • Solid state operation • Environmentally friendly DC Connection of the Three National Power Grids Clovis, NM Qiang Li (CES Brookhaven), Selva Selvamanickam, D Hazelton (SuperPower and University of Houston), V.R. Ramanan (ABB) Source: Matthews, Physics Today 62(4), 25 (2009) Light Weight, High Capacity Offshore Wind Turbines Raising Critical Current and Lowering In-field Anisotropy irradiation with heavy ions from Argonne’s ATLAS accelerator in two directions  splayed linear defects Critical Current Anisotropy in Cables • Many commercial superconductors show anisotropy of ~ 2 in the in-plane critical current Jcab when rotating magnetic field from perpendicular to parallel to the tape (red curve) • Overall tape performance is limited by the lowest Jcab values for some applications. • Heavy ion tracks are strong pinning defects for a single field direction. • Using Argonne’s ATLAS heavy ion accelerator, we • introduced tracks in two directions. Critical current density Jcc for current flow along the c-axis can be orders of magnitude lower than the in-plane critical current density Jcab in commercial YBCO tapes. (b) YBCO superconductor The critical current anisotropy  = Jcab / Jcc is found to reach 2070 in the highest-anisotropy tape, implying that ~20% of the tape width carries c-axis current in a helically wound ac power transmission cable, which could increase ac losses. The magnitude of Jcc (77 K, self-field) correlates to the concentration of in-plane stacking faults in YBCO thin films and so can be maximized by controlling stacking fault density. SuperPower commercial superconducting wire Splayed columnar defects are a new and powerful approach to raising critical current and lowering anisotropy. The lowest critical currents were raised by a factor of 2, and the anisotropy was reduced to ~ 1.2. The next challenges are to optimize the splay and introduce splayed columnar defects by chemical self-assembly. Center for Emergent Superconductivity Ying Jia, Lei Fang, Ulrich Welp, Wai Kwok, George Crabtree (Argonne) Jim Zuo (Illinois) SuperPower and University of Houston: Goran Majkic, Selva Selvamanickam CES: Y Jia, J Hu, G W Crabtree, W K Kwok, U Welp, AMSC: A P Malozemoff, M Rupich and S Fleshler Ames Lab: J R Clem Theory and Simulations of Strong Pinning by Nanoparticles Imaging Hot Spots in Commercial Superconductors • Pinning via trapping of vortex line segments • Simulations consistent with dynamic-trapping estimates • anisotropic line displacements • critical force  (pin density)0.5 • local stress grows with line length • Thermal fluctuations • strongly suppress apparent critical force • reduce anisotropy of displacements • straighten the lines near critical force Magneto-optical image of vortex generation and motion under current pulses. Excessive vortex motion causes the temperature to rise above Tc in hot spots as evidenced by the loss of contrast in the right most image. Associated with the hot spot is the rapid increase of the voltage. T=80K Critical force vs density of pins and temperature Snapshot of trapped vortex line near critical force i i CES: V. K. Vlasko-Vlasov, G W Crabtree, W K Kwok, U Welp AMSC: A P Malozemoff, M Rupich and S Fleshler CES: Alex Koshelev (Argonne) and A. Kolton (Centro Atomico Bariloche and Instituto Balseiro, Argentina) Commercial superconducting wires offer powerful solutions to fundamental grid challenges: 5x increase in urban power delivery; high capacity DC interconnect among the three national power grids; high capacity, low voltage long distance DC transmission; high capacity, low weight offshore wind turbines; and high efficiency, fast response energy storage. The grand scientific challenges to achieve these solutions are raising the critical current and lowering its anisotropy to achieve a factor of two or more increase in performance and reduction in cost. Authors Argonne National Laboratory George W. Crabtree, Alexei E. Koshelev, Wai-Kwong Kwok Vitalii Vlasko-Vlasov, Ulrich Welp, Lei Fang, Ying Jia University of Illinois at Urbana-Champaign Jim Zuo Brookhaven National Laboratory Qiang Li, Peter Johnson, Vycheslav Solovyov, Jim Misewich American Superconductor Corporation Steven Fleshler, Marty Rupich, Alexis P. Malozemoff SuperPower and University of Houston Goran Majkic, Venkat Selvamanickam, Drew. Hazelton Ames Laboratory John R. Clem Centro Atomico Bariloche and Instituto Balseiro, Argentina A. Kolton