New Transmission Options Case Study Superconductor Cables. Transmission Policy Institute Sheraton Downtown Denver, Colorado April 20-21, 2011

Transcription

1 New Transmission Options Case Study Superconductor Cables Transmission Policy Institute Sheraton Downtown Denver, Colorado April 20-21,

2 What is a Superconductor? Superconductors 100/25 Superconductors are materials that exhibit unique electrical characteristics: - Little to no resistance to the flow of electricity - Ability to carry hundreds of times as much electrical current as copper - Repel magnetic fields Current Capacity Equivalents These characteristics require: - Cooling below a critical temperature - Current levels below a critical current Above these critical levels the material quenches, and current must flow elsewhere New, ceramic high temperature superconductor (HTS) material discovered in Requires less cooling; cost effective liquid nitrogen may be used Development of HTS has enabled utility commercial applications

3 Superconductor Cable s ELECTRICAL Characteristics Very high power transfer capability compared to conventional cables solves many siting problems Very low impedance reduces loading on parallel lines and equipment Minimal magnetic field and elimination of heat simplifies placement concerns, minimizes right-of-way, and is easy on the environment Optional HTS cables with fault current management capabilities eliminate need to upgrade existing equipment HTS Cables offer unique capabilities

4 Superconductor Cables Driving to Commercial Adoption US/EPRI 115kV (50m) US/Southwire 12.5kV (30m) DENMARK 36kV (30m) China/SGCC 110kV (1km) JAPAN 66kV (30M) Korea/KEPCO 154kV (1km) US/DTE 24kV (120m) Korea 22.9kV (3km) KOREA 22.9kV (30m) CHINA 35kV (30m) JAPAN 77kV (500m) CHINA 10.5kV (75m) KOREA 22.9kV (100m) US/Nat. Grid 34.5kV (400m) US/AEP 13.8 kv (200m) US/LIPA Phase I 138kV (600m) MEXICO 15kV (30m) SPAIN 10kV (30m) KOREA 22.9kV (100m) RUSSIA 35 kv (30m) CHINA 110 kv (30m) JAPAN 66kV (250m) US/ConEd 13.8 kv (220m) US/LIPA Phase II 138 kv (600m) SPAIN 20kV (30m) KOREA/KEPCO 22.9kV (500m) KOREA/KEPCO 154kV (100m) SHANGHAI PROJECT (SECRI) US/TresAmigas-200kVdc(10km) Powered by AMSC wire Powered by other wire Undecided Project list updated Dozens of successful HTS cable projects globally in service or in process 4

5 Key HTS Cable PHYSICAL Characteristics Familiar Physical Characteristics Looks like conventional cable May be spliced May be placed in ducts or direct buried Must be cooled with liquid nitrogen No thermal constraints for placement Unique Electrical Characteristics Very high power transfer capability Very low impedance Minimal magnetic field Elimination of heat HTS cables with fault current management HTS Cables offer unique capabilities in a familiar package

6 Power Transfer Equivalency of Superconductor Cables 345kV 230kV 138kV 69kV 34.5kV 13.8kV XLPE HTS XLPE XLPE HTS XLPE HTS XLPE XLPE HTS Power Transfer Capability - 3-phase MVA Same Voltage, More Power - Greatly increased power transfer capacity at any voltage level Same Power, Lower Voltage - New MV versus HV Siting Opportunity MV Transmission Ideal for NIMBY & ROW sparse environments * No XLPE cable de-rating factors applied. Superconductor rating based on conventional 4000A breaker rating Superconductor cables provide transmission-level power transfer at medium voltage

7 Simplifying Transmission Siting One MV HTS Cable can replace: Many conventional underground circuits Overhead transmission line Photo courtesy Consolidated Edison HTS Cables Offer New Options to Siting Power Lines

8 Background Holbrook Superconductor

9 LIPA 3 LIPA is a NYS Authority established in 1998 as the primary electric service provider for LI 1207 sq. mi. (roughly 100 miles by 12 miles) Nassau, Suffolk and the Rockaway Peninsula Population of about 3 million 1.1 million residential customers 100,000 commercial customers Since 1998, 5.7% population growth (172,000 more people) $2.0 billion invested in system upgrades and improvements LIPA owns the assets All T&D operations and most IS systems are outsourced

10 LIPA Transmission System

11 Why was LIPA Interested in a Superconductor Cable? LIPA Long Term Needs Must meet increasing power demands in existing ROWs Load continues to increase LIPA expects 1200 MW of new load by Major transmission reinforcements will be required Project Provides Potential Tool to Meet LIPA s Long Term Needs ROW Congestion - HTS Cables provide increased power transfer capability within existing ROWs (2-5 times the capacity in the same space) Overhead Permitting Problems Potential cost savings compared to upgrading to 345 kv transmission system Site Specific East / West transfer capability increase required by upcoming power insertions

12 Land and Route Port Jefferson Shoreham Wading River Miller Place Terryville Centereach Superconductor Holbrook Substation

13 Superconductor Example: 138 kv, 575MW Capacity 200 ft ROW Self contained thermal envelope No thermal de-rating Minimal magnetic field No parallel line derating Lower Impedance Longer practical distance 4 ft ROW Superconductor Cables Simplify Placement and Offer New Options to Siting Lines

14 Long Island Power Authority Cable System Energized in April 2008 World s first HTS transmission voltage cable system in the grid Longest, most powerful superconductor cable in the world Able to carry 574 MW of power in a four-foot-wide right of way Landmark cable installation proving high power, transmission level applications Over 15 years of HTS Cable Experience 16

15 Next Step?? Holbrook Superconductor

16 Proposed Future Project Required to Support East/West Power Flows Extend 138kV superconductor cable to meet future transmission requirements Located between Holbrook and Central Islip substations (6.2 miles) Originally planned for summer 2012 delayed due to lower load growth ALL underground; eliminates need for conventional overhead-underground hybrid

17 Present Status and Future Direction of HTS Power Application in KEPCO Y o u n g - J i n W O N P o w e r G r i d P l a n n i n g T e a m, K E P C O 19

18 Ⅱ. Why? HTS System in KEPCO? High cost for Civil works Difficulty of excavating roads for const n conduit or culvert NIMBY for the construction of new substations To cope with continuous increasing of fault current Countermeasures to renew the aged power cables Large Capacity & Low loss + Eco-friendly HTS Cable & SFCL 8

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20 Supplying the huge buildings with electric power by HTS cables Replacing 22.9kV conventional cables(2~3lines) with the superconducting cables using the existing conduit or culverts without additional civil works 22.9 kv Superconducting Cables to replace 154 kv conventional cables 154 kv S/S in the suburbs SFCL Downtown Area 22.9 kv SW/S Circuit Breaker (Normal open) ~ SFCL 22.9 kv SW/S 22.9 kv Superconducting Cables to replace 22.9kV conventional cables SFCL Superconducting Transformers 22.9 kv SW/S

21 Superconducting Power System (SPS) applying distributed switching stations for metropolitan areas Apply superconducting power devices (cables, transformers, FCLs) to real power system 154kV transmission power system 22.9kV superconducting power system Replace 154kV substations in downtown with 22.9kV underground switching stations Replace 154kV conventional cables with 22.9kV superconducting cables Bulk power transfer by superconducting cables and transformers & Fault current reduction by SFCL 154kV conventional cables 154kV S/S 154kV S/S Suburb 154kV S/S Downtow n 154kV S/S Skip substations Reduce construction costs Environmentfriendly 154kV conventional cables 154kV S/S 22.9kV SW/S 22.9kV SW/S Suburb 22.9kV SW/S 22.9kV SW/S Downtow n 154kV S/S Avoid civil petitions 22.9kV SW/S 22.9kV SW/S 22.9 kv Superconducting cables

22 One of solutions for the site problem No substations & Compact size Easy to find a site for power facilities in downtown Underground switching stations Make a park on the switching stations Economic benefits Reduction of cost for buying land The site for 22.9kV switching stations is less than 30%, compared to 154kV substations. No additional construction cost We can use established underground facilities such as existing electric power conduit pipes. Environmental and social benefits Environment-friendly Avoid the trend of NIMBY No oil for cooling the system Free of the explosion danger (Superconducting transformer) No additional construction Reduce the construction cost and ease traffic congestion High efficiency and loss of superconductor Save energy and reduce CO2 emission

23 DC Superconductor cables for long distance transmission 25

24 Superconductor Advantages with DC Power When carrying DC current, superconductors themselves are perfectly lossless - Regardless of length - Regardless of power rating Benefits - No power limitations based on current-based losses - Allows lower voltage, higher current transmission - Allows underground construction Superconductors open the door for a true underground transmission system

25 Superconductor PowerPipes Superconductor PowerPipes combine: Superconductor cables DC power transmission The result: A high capacity electric transmission pipeline that is: Underground and easy to site Highly efficient Offers greater security than other technologies Provides for multiple power on- and off-ramps

26 Today s Key Energy Challenge: Carrying 100 s of Gigawatts of Green Power to Market Many Issues Multiple Sources Multiple Destinations Cost Allocation Siting Transmission Across Interconnections Losses The challenge of moving renewable power long distances needs another option 28

27 Power Transfer Capability, GW % Losses (Est.) AC Overhead Transmission Higher power and longer distances require higher 5GW of Renewable Energy Transmission voltages Losses Limited power flow control Power transmission characteristics Public opposition Dominant form of transmission, but many challenges 16% 14% 12% 10% 8% 6% 4% 2% 0% Miles Range of Losses for Various 765kV Overhead Line Designs Transfer Capability Versus Distance of a 765 kv Overhead Line Line Length in Miles 29 Courtesy Argonne National Lab

28 Existing Transmission Options TRANSMISSION LINE POWER AND DISTANCE SUITABLE TRANSMISSION SOLUTIONS Overhead Solutions Underground Solutions Point-to- Point HVDC Multiterminal VSC HVDC Point-to- Point HVDC Multiterminal VSC HVDC REQUIREMENTS AC AC Low Power (<1GW) Short (<100 mile) lines Low Power (<1GW) Moderate ( mile) lines Low Power (<1GW) Long (>400 mile) lines Moderate Power (1-5GW) Short (<100 mile) lines Moderate Power (1-5GW) Moderate ( mile) lines Moderate Power (1-5GW) Long (>400 mile) lines High Power (>5GW) Short (<100 mile) lines High Power (>5GW) Moderate ( mile) lines High Power (>5GW) Long (>400 mile) lines Multi-Terminal Superconductor Pipeline No suitable solution for high power, long distance, underground transmission 30

29 HVDC Superconductor Cables TRANSMISSION LINE POWER AND DISTANCE SUITABLE TRANSMISSION SOLUTIONS Overhead Solutions Underground Solutions Point-to- Point HVDC Multiterminal VSC HVDC Point-to- Point HVDC Multiterminal VSC HVDC Multi-Terminal Superconductor Pipeline REQUIREMENTS AC AC Low Power (<1GW) Short (<100 mile) lines Low Power (<1GW) Moderate ( mile) lines Low Power (<1GW) Long (>400 mile) lines Moderate Power (1-5GW) Short (<100 mile) lines Moderate Power (1-5GW) Moderate ( mile) lines Moderate Power (1-5GW) Long (>400 mile) lines High Power (>5GW) Short (<100 mile) lines High Power (>5GW) Moderate ( mile) lines High Power (>5GW) Long (>400 mile) lines Fit of DC superconductor cables for underground, long distance, high power, multi-terminal transmission 31

30 Losses (% of 5GW) Operational Opportunities for DC Superconductor Cables: ELECTRICAL EFFICIENCY 14% 12% 10% 8% 6% 4% 2% 765kV OH, 2 Lines 765kV OH, 3 Lines +/-300kV Underground DC [6] Overhead +/-800kV DC [7] +/-200kV Superconductor Pipeline Optimized 765kV, 3 Lines [8] Losses for 5GW Transmission 0% Length (miles) Converter losses 2%, cooling losses 22kW/km Overall losses 2.75% for (2.4% for 10GW) Loss advantage increases with distance and MW rating 32

31 Rights of Way Already Exist for Superconductor Electricity Pipelines 33

32 Cost Analysis 5GW, 1000 mile Superconductor DC Cable System - US$8.8 Million/mile two pole cable - Costs include DC terminals, refrigeration, installation - Doubling capacity to 10GW increases cable cost by only 50% (extra converters not included) Cost Competitive with EHV AC - US$2.5 - $5.5 Million/mile - 2 to 3 lines needed for same capacity Long distance, high power superconductor DC cables are cost competitive with EHV AC lines 34

33 Advantages of DC Superconductor Cables Highest power capacity Highest efficiency (lowest power losses) of any transmission technology Ideal for very long distances Capable of transferring power across the three U.S. interconnections Able to accept power from multiple distributed sources, and precisely deliver power to multiple distributed destinations Underground construction with minimum right of way requirement Simplified cost allocation due to precise controllability of DC terminals Minimizes interaction with existing AC grid, reducing costs and increasing operational flexibility Cost competitive DC Superconductor PowerPipes are uniquely and ideally suited to move renewable energy to distant load centers

34 Tres Amigas SuperStation Project Western Interconnection Eastern Interconnection Texas Interconnection Unique 3-way DC project to link the three U.S. Interconnections

35 Tres Amigas Project to Use Superconductor Electricity Pipeline 37

36 Summary AC and DC superconductor cables offer new option for high power, underground, transmission of electric power Transmission Grid of the Future 38