1. The SuperCable: Dual Delivery of Chemical and Electric Power
Paul M. Grant
EPRI Science Fellow (retired)
IBM Research Staff Member Emeritus
Principal, W2AGZ Technologies
2004 SuperGrid 2
October 2004, Urbana, Il
Technical Plenary Session – Levis Faculty Center -- UIUC
Monday, 25 October 2004, 9:30 AM

2. The Discoveries
Zürich, 1986
Leiden, 1914

3. Superconductivity 101 + • e - • - e

4. GLAG

5. The Flavors of Superconductivity
HC1 H -M
Meissner
Normal TC
Temperature
Magnetic Field
 < 
Type I

6. Abrikosov Vortex LatticeH

7. The Flavors of Superconductivity
 > 
Type II
1/4p
HC1 H -M
Meissner
Normal TC
Temperature
Magnetic Field
HC2
Mixed

8. Abrikosov Vortex LatticeH F J

9. The Flavors of Superconductivity
 > 
Type II
1/4p
HC1 H -M
Meissner
Normal TC
Temperature
Magnetic Field
HC2
Mixed
NOT
PERFECT
CONDUCTOR!

10. Abrikosov Vortex LatticeH
“Pinned” F J

11. The Flavors of Superconductivity
Meissner
HC1
Normal TC
Temperature
Magnetic Field
HC2
HC2
Normal
R  0
Magnetic Field
R = 0
Mixed
Mixed
HC1
Meissner TC
Temperature

12. No More Ohm’s Law
E = aJn
n = 15
T = 77 K
HTS Gen 1
E = 1 V/cm

13. ac Hysteresis
1/4p
HC1 H -M
HC2

14. TC vs Year: 1991 - 2001 Temperature, TC (K) Year 200 1900 1920 1940
1960
1980
2000
High-TC
164 K
150
Temperature, TC (K)
100 50
MgB2
Low-TC
Year

15. HTSC Wire Can Be Made! But it’s 70% silver! Oxide Powder
Mechanically Alloyed Precursor 1.
Powder
Preparation
Billet Packing
& Sealing 2.
A. Extrusion
B. Wire Draw
C. Rolling
Deformation
& Processing 3.
Oxidation -
Heat Treat 4.
But it’s 70% silver!

16. Finished Cable

17. Reading Assignment Garwin and Matisoo, 1967 (100 GW on Nb3Sn)
Bartlit, Edeskuty and Hammel, 1972 (LH2, LNG and 1 GW on LTSC)
Haney and Hammond, 1977 (Slush LH2 and Nb3Ge)
Schoenung, Hassenzahl and Grant, 1997 (5 GW on HTSC, 1000 km)
Grant, 2002 (SuperCity, Nukes+LH2+HTSC)
Proceedings, SuperGrid Workshop, 2002
These articles, and much more, can be found at sub-pages SuperGrid/Bibliography

18. 1967: SC Cable Proposed!
100 GW dc, 1000 km !

19. “Hydricity” SuperCables+v I -v H2
Circuit #1 +v I I -v
Multiple circuits
can be laid
in single trench H2 H2
Circuit #2

20. SuperCable

21. Power Flows Electricity Hydrogen PSC = 2|V|IASC, where
PSC = Electric power flow
V = Voltage to neutral (ground)
I = Supercurrent
ASC = Cross-sectional area of superconducting annulus
Electricity
PH2 = 2(QρvA)H2, where
PH2 = Chemical power flow
Q = Gibbs H2 oxidation energy (2.46 eV per mol H2)
ρ = H2 Density
v = H2 Flow Rate
A = Cross-sectional area of H2 cryotube
Hydrogen

22. Power Flows: 5 GWe/10 GWth

23. Radiation Losses WR = 0.5εσ (T4amb – T4SC), where
WR = Power radiated in as watts/unit area
σ = 5.67×10-12 W/cm2K4
Tamb = 300 K
TSC = 20 K
ε = 0.05 per inner and outer tube surface
DH = 45.3 cm
WR = 16.3 W/m
Superinsulation: WRf = WR/(n-1), where
n = number of layers = 10
Net Heat In-Leak Due to Radiation = 1.8 W/m 

24. Fluid Friction Losses Wloss = M Ploss /  ,
Where M = mass flow per unit length
Ploss = pressure loss per unit length
 = fluid density
Fluid Re
(mm)
DH (cm)
v (m/s) P
(atm/10 km)
Power
Loss (W/m)
H (20K)
2.08 x 106
0.015
45.3
4.76
2.0
3.2

25. SuperCable Losses (W/M)
Heat Removal
dT/dx = WT/(ρvCPA)H2, where
dT/dx = Temp rise along cable, K/m
WT = Thermal in-leak per unit Length
ρ = H2 Density
v = H2 Flow Rate
CP = H2 Heat Capacity
A = Cross-sectional area of H2 cryotube
SuperCable Losses (W/M)
K/10km
Radiative
Friction
ac Losses
Conductive
Total
dT/dx
1.8
3.2 1 7
10-2

26. LH2 in 45 cm diameter, 12 mile bipolar SuperCable
SuperCable H2 Storage
Some Storage Factoids
Power (GW)
Storage (hrs)
Energy (GWh)
TVA Raccoon Mountain
1.6 20 32
Alabama CAES 1
Scaled ETM SMES 8
One Raccoon Mountain = 13,800 cubic meters of LH2
LH2 in 45 cm diameter, 12 mile bipolar SuperCable
= Raccoon Mountain

27. H2 Gas at 77 K and 1850 psia has 50% of the energy content of liquid H2
and 100% at 6800 psia

28. “Hybrid” SuperCable

29. Electrical Issues Voltage – current tradeoffs AC interface (phases)
“Cold” vs “Warm” Dielectric
AC interface (phases)
Generate dc? Multipole, low rpm units (aka hydro)
Ripple suppression
Filters
Cryogenics
Pulse Tubes
“Cryobreaks”
Mag Field Forces
Splices (R = 0?)
Charge/Discharge cycles (Faults!)
Power Electronics
GTOs vs IGBTs
12” wafer platforms
Cryo-Bipolars

30. Construction Issues Pipe Lengths & Diameters (Transportation)
Coax vs RTD
Rigid vs Flexible?
On-Site Manufacturing
Conductor winding (3-4 pipe lengths)
Vacuum: permanently sealed or actively pumped?
Joints
Superconducting
Welds
Thermal Expansion (bellows)

31. Jumpstarting the SuperGrid
Do it with SuperCables
Focus on the next two decades
Get started with superconducting dc cable interties & back-to-backs using existing ROWs
As “hydrogen economy” expands, parallel/replace existing gas transmission lines with SuperCables
Start digging

33. Al-Can Gas Pipeline Proposals

34. Mackenzie Valley Pipeline
1300 km
18 GW-thermal

35. Electrical Insulation
LNG SuperCable
Electrical Insulation
“Super-Insulation”
Superconductor
105 K
1 atm (14.7 psia)
Liquid 77 K
Thermal Barrier to LNG

36. SuperCable Prototype ProjectH2 e–
Cryo I/C Station
H2 Storage SMES
500 m Prototype
“Appropriate National Laboratory”

37. Regional System Interconnections