Center for Emergent Superconductivity

Superconductivity as an Energy Carrier

Electricity Grid ChallengesCapacity, 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.

2nd Generation High Temperature Superconducting Wire

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.

AuthorsArgonne National LaboratoryGeorge W. Crabtree, Alexei E. Koshelev, Wai-Kwong Kwok Vitalii Vlasko-Vlasov, Ulrich Welp, Lei Fang, Ying Jia

University of Illinois at Urbana-ChampaignJim Zuo

Brookhaven National LaboratoryQiang 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 Ic > 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 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.

(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 CablesRaising 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 2nd generation coated conductors. Only one layer, ~ 1 micron thick, is the superconductor.

Imaging Hot Spots in Commercial Superconductors

Lead Institution Partner Institutions Industry and University AffiliatesBrookhaven National Laboratory Argonne National Laboratory American Superconductor

University of Illinois at Urbana-Champaign SuperPower / University of Houston

Center for Emergent SuperconductivityDirector : J.C. Davis

LaMnO3 buffer

YBCO superconductor

Ag cap layer

Ni alloy substrate

Al2O3 / Y2O3 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 ElectricityDC Superconducting Transmission

DC Connection of theThree National Power Grids

Clovis, NMLight Weight, High Capacity

Offshore Wind Turbines

Urban Power DeliveryLong 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

250 750 1250M

W

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 SuperconductivityYing Jia, Lei Fang, Ulrich Welp, Wai Kwok, George Crabtree (Argonne) Jim Zuo

(Illinois)SuperPower and University of Houston: Goran Majkic, Selva Selvamanickam

pristine

40

50

60

70

80

90

-100 -50 0 50 100Jc(A/cm)_refJc (A/cm)_415_2

Jc (A

/cm

)

Magnetic Field Direction (deg)

H || ab H || c H || ab

T = 77 KH = 1 T

irradiation dose

YBCO superconductor

SuperPowercommercial superconducting wire

H

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.

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.

i i ii

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 CorporationSteven Fleshler, Marty Rupich, Alexis P. Malozemoff

SuperPower and University of HoustonGoran Majkic, Venkat Selvamanickam, Drew. Hazelton

Ames LaboratoryJohn R. ClemCentro Atomico Bariloche and Instituto Balseiro, ArgentinaA. Kolton

CES: Y Jia, J Hu, G W Crabtree, W K Kwok, U Welp,AMSC: A P Malozemoff, M Rupich and S FleshlerAmes Lab: J R Clem

4A

U(mV)

CES: V. K. Vlasko-Vlasov, G W Crabtree, W K Kwok, U WelpAMSC: A P Malozemoff, M Rupich and S Fleshler

Magneto-optical image of vortexgeneration and motion under current pulses. Excessive vortexmotion 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.

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 ~ B2 Size ~ R2, (~ R3 for batteries) Solid state operation Environmentally friendly

Superconductivity has solutions for all of these challenges.