1. Center for Emergent Superconductivity Superconductivity as an Energy Carrier Electricity Grid Challenges 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. 2 nd Generation High Temperature Superconducting Wire Because they generate little or no heat, 2 nd generation coated conductors made from the 92 K superconductor YBa 2 Cu 2 O 7 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. 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 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 I c > 600 A  Modular, scalable converter concept for direct connection to medium voltage grid with high round trip efficiency (> 85%) Many commercial superconductors show anisotropy of ~ 2 in the in- plane critical current J cab when rotating magnetic field from perpendicular to parallel to the tape (red curve) Overall tape performance is limited by the lowest J cab 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. (b) 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. Superconducting Grid Solutions Modular SMES Critical Current Anisotropy in Cables Raising Critical Current and Lowering In-field Anisotropy The lowest critical currents were raised by a factor of 2, and the anisotropy was reduced to ~ 1.2. Multilayer architecture of 2 nd generation coated conductors. Only one layer, ~ 1 micron thick, is the superconductor. Imaging Hot Spots in Commercial Superconductors Lead InstitutionPartner InstitutionsIndustry and University Affiliates Brookhaven National LaboratoryArgonne National LaboratoryAmerican Superconductor University of Illinois at Urbana-ChampaignSuperPower / University of Houston Center for Emergent Superconductivity Director: J.C. Davis LaMnO 3 buffer YBCO superconductor Ag cap layer Ni alloy substrate Al 2 O 3 / Y 2 O 3 Ni barrier MgO template Cu shunt layer Conventional Gearbox 5 MW ~ 410 tons Conventional Gearless 6 MW ~ 500 tons HTS Gearless 8 MW ~ 480 ton (AMSC) Interstate Highway System for Electricity DC Superconducting Transmission DC Connection of the Three National Power Grids Clovis, NM Light Weight, High Capacity Offshore Wind Turbines Urban Power Delivery Long Island, NY 60 MJ 2.5 MJ Qiang Li (CES Brookhaven), Selva Selvamanickam, D Hazelton (SuperPower and University of Houston), V.R. Ramanan (ABB) Minutes since start of day 3 2 1 2507501250 MW Solar PV The variability of wind and solar electricity requires storage for wide penetration irradiation with heavy ions from Argonne’s ATLAS accelerator in two directions  splayed linear defects 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 pristine with splay YBCO superconductor SuperPower commercial superconducting wire H The critical current anisotropy  = J cab / J cc 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 J cc (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. Critical current density J cc for current flow along the c- axis can be orders of magnitude lower than the in-plane critical current density J cab in commercial YBCO tapes. i i i i T=80K Theory and Simulations of Strong Pinning by Nanoparticles Superconducting Magnetic Energy Storage The grand scientific challenges for high temperature superconductor applications are to raise the magnitude and lower the anisotropy of the current carrying capability. Source: American Superconductor The next challenges are to optimize the splay and introduce splayed columnar defects by chemical self-assembly. Splayed columnar defects are a new and powerful approach to raising critical current and lowering anisotropy. 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 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 4A U(mV) CES: V. K. Vlasko-Vlasov, G W Crabtree, W K Kwok, U Welp AMSC: A P Malozemoff, M Rupich and S Fleshler Magneto-optical image of vortex generation and motion under current pulses. Excessive vortex motion causes the temperature to rise above T c 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. Source: Matthews, Physics Today 62(4), 25 (2009) Snapshot of trapped vortex line near critical force Critical force vs density of pins and temperature 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 CES: Alex Koshelev (Argonne) and A. Kolton (Centro Atomico Bariloche and Instituto Balseiro, Argentina) Ultra High Field SMES Benefits:  Fast dynamic response  Nearly infinite cycling  Magnetic energy ~ B 2  Size ~ R 2, (~ R 3 for batteries)  Solid state operation  Environmentally friendly Superconductivity has solutions for all of these challenges.