South Australian Transmission Annual Planning Report May 2015 Disclaimer The purpose of this document is to provide information about ElectraNet's assessment of the transmission system’s likely capacity to meet demand in South Australia over the next ten years. It also provides information about ElectraNet’s intended plans for augmentation of the transmission network. This document is not to be used by any party for other purposes, such as making decisions to invest in further generation, transmission or distribution capacity. This document has been prepared using information provided by, and reports prepared by, a number of third parties. Anyone proposing to use the information in this document should independently verify and check the accuracy, completeness, reliability and suitability of the information in this document, and the reports and other information relied on by ElectraNet in preparing it. This document contains certain predictions, estimates and statements that reflect various assumptions concerning, amongst other things, economic growth scenarios, demand forecasts and developments within the National Electricity Market. These assumptions may or may not prove to be accurate. The document also contains statements about ElectraNet’s future plans. Those plans may change from time to time and should be confirmed with ElectraNet before any decision is made or action is taken based on this document. ElectraNet makes no representation or warranty as to the accuracy, reliability, completeness or suitability for particular purposes of the information contained within this document. ElectraNet and its employees, agents and consultants shall have no liability (including liability to any person by reason of negligence or negligent misstatement) for any statements, opinions, information or matter expressed or implied arising out of, contained in, or derived from, or for any omissions from, the information in this document, except in so far as liability under any statute cannot be excluded. Company Information ElectraNet Pty Ltd ABN 41 094 482 416 Address: 52-55 East Terrace Adelaide South Australia 5000 Telephone: +61 8 8404 7966 www.electranet.com.au Contact Information Please direct Transmission Annual Planning Report enquiries to: Hugo Klingenberg Senior Manager Network Development [email protected] Page 2 of 140 South Australian Transmission Annual Planning Report May 2015 Contents GLOSSARY OF TERMS..............................................................................................................8 EXECUTIVE SUMMARY ...........................................................................................................10 1. INTRODUCTION ............................................................................................................15 1.1 ELECTRANET’S ROLE IN THE SUPPLY OF ELECTRICITY ............................................................ 15 1.2 PURPOSE OF THIS TRANSMISSION ANNUAL PLANNING REPORT ............................................... 16 1.3 CONTINUAL IMPROVEMENT .................................................................................................... 17 1.4 RESPONSIBILITIES ................................................................................................................. 17 1.4.1 Rule Requirements for the Transmission Annual Planning Report .................................... 18 1.5 TRANSMISSION PLANNING FRAMEWORK ................................................................................. 18 1.5.1 Network Planning Approach ............................................................................................... 19 1.5.2 Reliability Standards ........................................................................................................... 19 1.5.3 Regulatory Investment Test for Transmission (RIT-T) ....................................................... 21 1.6 STRUCTURE OF THIS TRANSMISSION ANNUAL PLANNING REPORT ........................................... 22 2. OVERVIEW OF THE SOUTH AUSTRALIAN TRANSMISSION SYSTEM ..................... 23 2.1 BACKGROUND ....................................................................................................................... 23 2.2 RECENT DEVELOPMENTS ...................................................................................................... 25 2.3 EXISTING TRANSMISSION NETWORK ...................................................................................... 26 2.3.1 Main Grid ............................................................................................................................ 26 2.3.2 Regional Networks ............................................................................................................. 27 2.3.2.1 Metropolitan ........................................................................................................................ 27 2.3.2.2 Eastern Hills ....................................................................................................................... 28 2.3.2.3 Mid North ............................................................................................................................ 28 2.3.2.4 Riverland............................................................................................................................. 28 2.3.2.5 South East .......................................................................................................................... 29 2.3.2.6 Eyre Peninsula ................................................................................................................... 29 2.3.2.7 Upper North ........................................................................................................................ 29 2.4 INTER-REGIONAL TRANSFER CAPABILITY ................................................................................ 30 2.4.1 Heywood Interconnector ..................................................................................................... 30 2.4.1.1 Import Capability ................................................................................................................. 31 2.4.1.2 Export Capability ................................................................................................................ 31 2.4.2 Murraylink Interconnector ................................................................................................... 32 2.4.2.1 Import Capability ................................................................................................................. 32 2.4.2.2 Export Capability ................................................................................................................ 33 3. NATIONAL TRANSMISSION NETWORK DEVELOPMENTS AND SOUTH AUSTRALIAN TRANSMISSION CONSTRAINTS ..........................................................34 3.1 2014 NATIONAL TRANSMISSION NETWORK DEVELOPMENT PLAN (NTNDP) ............................. 34 3.2 TRANSMISSION NETWORK DEVELOPMENT IDENTIFIED IN THE NTNDP ..................................... 35 3.3 TRANSMISSION NETWORK CONSTRAINTS ............................................................................... 36 3.4 NETWORK MARKET BENEFIT PROJECTS ................................................................................. 46 3.5 FUTURE NETWORK CONGESTION ............................................................................................ 49 Page 3 of 140 South Australian Transmission Annual Planning Report May 2015 4. DEMAND FORECASTS AND SUMMER REVIEW .........................................................51 4.1 DEMAND FORECAST .............................................................................................................. 52 4.1.1 Review of 2014 National Electricity Forecasting Report .................................................... 52 4.1.2 AEMO’s Connection Point Forecasts ................................................................................. 53 4.1.3 Reconciliation ..................................................................................................................... 53 4.2 SUMMER REVIEW .................................................................................................................. 54 4.2.1 State-wide ........................................................................................................................... 54 4.2.2 Connection Point Review ................................................................................................... 57 5. SIGNIFICANT PLANNING INVESTIGATIONS ..............................................................58 5.1 UPPER SOUTH EAST TRANSMISSION CORRIDOR MARKET BENEFIT STUDY .............................. 58 5.2 MURRAYLINK SUPPORT TO SOUTH AUSTRALIAN RIVERLAND AND REGIONAL VICTORIA: JOINT ELECTRANET – AEMO STUDY .............................................................................................. 59 5.3 RENEWABLE GENERATION INTEGRATION: JOINT ELECTRANET – AEMO STUDY ....................... 59 5.4 FREQUENCY CONTROL FOLLOWING SEPARATION OF SOUTH AUSTRALIA FROM THE NEM ......... 61 5.5 TRANSFORMER AND TRANSMISSION LINE THERMAL RATINGS REVIEW ..................................... 61 5.6 PLANNED AND RECENTLY COMMENCED STRATEGIC STUDIES .................................................. 62 5.6.1 System Integration of Heywood Interconnector Upgrade .................................................. 62 5.6.1.1 South East Under-Frequency Tripping Scheme................................................................