Cryogenic Efficiency & Losses in AC Power Machines Dr. Philip Sargent MIM MBCS CDipAF CEng. Diboride Conductors Ltd.

Power Superconductors

Cost of Capital – when the superconductor is costly Lower running costs, Cheap capital, Cheap superconductor Lower capital costs, Expensive capital

Constraint: Liquid Cryogens Optimal Range LOX!

Engineering Needs Generators, Transformers, Cables, FCLs, Motors, Grid conditioning, power storage Capital cost is most important for all of these in deregulated power markets Why superconductors? Higher power density, 100x the current Smaller Lighter (MgB 2 is 1/3 the density of Copper) Cheaper to buy and install Cheaper to operate Entirely new capabilities (FCLs)

HyperTech CTFF for MgB 2 CONTINUOUS TUBE FORMING AND FILLING (CTFF)

Boron Chemistry Pyrometallurgy: Mg + B + heat Powder in tube in situ Powder in tube ex situ Powder in tube ex situ + Mg Powder in tube + HIP CVD Mg + diborane Electrochemistry: Mg-borates in KCL Other chemical routes… ??

Materials Requirements Magnetic Fields 2-5 T (except cables) AC use requires T > 20 K (cryogenic cost) Materials parameters: Low cost: ~ 10 $/kA.m Practical volumes: J e (J c 10 5 A/cm 2 ) Low AC losses: W/kA.m at 50Hz. Flexible, low J e / strain sensitivity

Targets Copper: 6 – 22 $/kA.m (400 to 100 A/cm 2 ) Bi2223: 100 – 25 $/kA.m (2002 – 2005) Device kA/cm 2 T $/kA.m Motor Generator Transformer <10 FCL Cable < Dick Blaugher, NREL

Market Segmentation Transformers and Fault-Current Limiters Motors, Generators, Energy-storage Power transmission Electronics

Wire$/kA.mCost Driver NbTi (4.2 K, 2 T)0.90Materials (Nb) Nb 3 Sn (4.2 K, 10 T)10Materials (Nb) Bi-2223 (25 K, 1 T)25Materials (Ag) Y-123 (25 K, 1 T)4Capital Plant MgB 2 (25 K, 1 T)0.8 – 3.6 ?Capital Plant Competitive Costs Paul Grant EPRI

Y-123 IBAD 77K, 0T Bi K, 0T NKT Target "Sokolowski Plot" of HTSC Wire Performance and Cost NbTi 4.2K, 2T Bi K, 0T IGC Nb 3 Sn 4.2K, T $1,000 $100 $10 $1 /kAm Operating Current, Ic (A) Cost ($/m) Bi K,0T ASC 50 Comparative Performance Paul Grant EPRI

Transformers: a big prize Cost of Ownership in $/kW 2000 ABB SPI Phase I Analysis Cu ( A/cm 2 HTS (68 K)MgB 2 (25 K) Losses60 Cryo- Wire5 Total Paul Grant EPRI

First Major Applications Current Leads? No. FCLs ? New capabilities! Transmission Cables ? Distribution Cables ? Dielectric + thermal + AC lossses Transformers ? 98% efficient. Generators ? Power stations,Wind turbines? Non-Utility Power Applications Motors 68% of industrial power Half of that over 750kW Power electronics & Cryogenics

Years Market Share 0% 100% Materials Changeovers

Effort Performance Technology S Curves

Effort Performance Copper-Iron HTCs MgB 2 75y16y 2002 Power Technologies

Conclusions Necessary Partner Technologies Cryogenics, not % reliable Power electronics, why use AC if DC can do it? Motors Higher power density, 100x the current Smaller, Lighter Cheaper to buy and install Transport: ships, trains Environmentally friendly Prefer wire not tape! 12 April 2002