SOUTH AUSTRALIAN HISTORICAL MARKET INFORMATION REPORT SOUTH AUSTRALIAN ADVISORY FUNCTIONS

Transcription

1 SOUTH AUSTRALIAN HISTORICAL MARKET INFORMATION REPORT SOUTH AUSTRALIAN ADVISORY FUNCTIONS Published: July 2014

2 IMPORTANT NOTICE Purpose This publication has been prepared by the Australian Energy Market Operator Limited (AEMO) using information available at 30 June 2014, unless otherwise specified. AEMO publishes the South Australian Historical Market Information Report in order to comply with section 50B of the National Electricity Law. The purpose of this publication is to provide information about historical levels of generation and interconnector supply. Information made available after 30 June 2014 may have been included in this publication where practical. Disclaimer AEMO has made every effort to ensure the quality of the information in this publication but cannot guarantee its accuracy or completeness. It incorporates information provided to AEMO by third parties. Accordingly, to the maximum extent permitted by law, AEMO and its officers, employees and consultants involved in the preparation of this publication: make no representation or warranty, express or implied, as to the currency, accuracy, reliability or completeness of the information in this publication; and are not liable (whether by reason of negligence or otherwise) for any statements, opinions, information or other matters contained in or derived from this publication, or any omissions from it, or in respect of a person s use of the information in this publication. Acknowledgement AEMO acknowledges the support, cooperation and contribution of all participants in providing data and information used in this publication The material in this publication may only be used in accordance with the copyright permissions on AEMO s website. Australian Energy Market Operator Ltd ABN info@aemo.com.au NEW SOUTH WALES QUEENSLAND SOUTH AUSTRALIA VICTORIA AUSTRALIAN CAPITAL TERRITORY TASMANIA

3 CONTENTS 1 INTRODUCTION Generation map 5 2 BACKGROUND 6 3 HISTORICAL GENERATION Generation changes Generation by fuel type Greenhouse gas emissions Capacity factors 13 4 INTER-REGIONAL SUPPLY Historical interconnector flows Average interconnector flow patterns Flow duration curves 25 5 LINKS TO SUPPORTING INFORMATION 28 MEASURES AND ABBREVIATIONS 29 Units of measure 29 Abbreviations 29 AEMO

4 TABLES Table 1: Historical energy generation for South Australian power stations (GWh) a 8 Table 2: Annual emission comparison, current versus previous thermal efficiencies and emission factors 13 Table 3: Historical Heywood Interconnector power flow 20 Table 4: Historical Murraylink Interconnector power flow 20 Table 5: Total interconnector power flow 21 FIGURES Figure 1: South Australian energy generation by fuel type (GWh), compared to Figure 2: South Australian key existing generators 5 Figure 3: Dispatch process flow chart 6 Figure 4: South Australian energy generation by fuel type 10 Figure 5: Registered capacity by fuel source, 2000 compared to Figure 6: Greenhouse gas emissions for South Australia per financial year 12 Figure 7: Financial year capacity factors for scheduled generators 14 Figure 8: Financial year capacity factors for non-scheduled and semi-scheduled generators (wind farms) 15 Figure 9: Summer capacity factors for scheduled generators 16 Figure 10: Summer capacity factors for non-scheduled and semi-scheduled generators (wind farms) 17 Figure 11: Winter capacity factors for scheduled generators 18 Figure 12: Winter capacity factors for non-scheduled and semi-scheduled generators (wind farms) 19 Figure 13: Total interconnector net imports 22 Figure 14: Combined interconnector daily 5-min average flow 23 Figure 15: Heywood, Murraylink and combined interconnector daily 5-min average flow 23 Figure 16: Combined interconnector summer daily 5-min average flow (business days only) 24 Figure 17: Combined interconnector winter daily 5-min average flow (business days only) 24 Figure 18: Heywood Interconnector flow duration curves 26 Figure 19: Murraylink Interconnector flow duration curves 26 Figure 20: Combined interconnector flow duration curves 27 Figure 21: Interconnector flow as a percentage of interconnector capacity 27 AEMO

5 Energy generation (Gwh) SOUTH AUSTRALIAN HISTORICAL MARKET INFORMATION REPORT 1 INTRODUCTION The South Australian Historical Market Information Report provides information on generation and interconnector supply between South Australia and Victoria over the last five years. The South Australian Government requested that the Australian Energy Market Operator (AEMO) prepare this report as a part of its 2014 South Australian Advisory Functions under section 50B of the National Electricity Law. Other documents AEMO publishes under these arrangements are available on its website. 1 Key changes in South Australia from to are: Total energy generation decreased by 8% (1,060 gigawatt-hours (GWh)) comprising: Gas generation decreased by 18% (1,233 GWh). Wind generation increased by 9% (312 GWh). Coal generation decreased by 6% (138 GWh). Diesel generation decreased by 25% (1 GWh). Greenhouse gas emissions reduced by 7% (0.44 megatonnes of carbon dioxide equivalent (MtCO2-e)). Total interconnector net imports from Victoria increased by 19% (268 GWh). Figure 1 shows the change in annual energy generation by fuel type, across compared to Figure 1: South Australian energy generation by fuel type (GWh), compared to ,000 12,000 3,483 10, ,796 8, ,000 4,000 6,768 5,533 2,000 2,238 2, Coal Gas Diesel Wind 1 Available at: Viewed on 7 July AEMO

6 This report comprises: Chapter 2: Background information including a brief explanation of the dispatch process and data AEMO uses for information in this report. Chapter 3: Historical information for the last five years on South Australian generation, generation by fuel type, generation greenhouse gas emissions, and generation capacity factor. Chapter 4: Historical information on interconnector flows between South Australia and Victoria over the last five years. This sets out average interconnector flow patterns and flow duration curves. Chapter 5: Links to supporting information. Additionally, the figures and tables used in this report are published on AEMO s website. 2 2 Available at: Report. AEMO

7 1.1 Generation map Figure 2 shows the location of key existing South Australian generators. Figure 2: South Australian key existing generators AEMO

8 2 BACKGROUND In the National Electricity Market (NEM), electricity is traded between market generators and market customers (typically retailers). 3 Generators make dispatch offers to supply the market with specified amounts of electricity at specific prices for each price period. From all the generation dispatch offers received, AEMO uses its central dispatch process to dispatch the cheapest generation available to meet the forecast electricity demand. This process determines a dispatch price every five minutes, and the six dispatch prices in each half-hour are averaged to determine the spot price for each NEM region. 4 AEMO uses the relevant spot price as the basis to settle all electricity traded in the NEM. The dispatch process uses actual or estimated values, which are the recorded supply values 5 at the start of each five-minute dispatch interval. These are often referred to as initial, measured, metered, or actual data. AEMO issues dispatch instructions to scheduled and semi-scheduled generators based on recorded supply values. 6 These targets are represented as cleared supply values, these are supply values projected for the end of the dispatch interval as an output of the dispatch process (see Figure 3). Figure 3: Dispatch process flow chart 3 The National Electricity Rules (NER) defines market generators and market customers. 4 In all cases, NEM Market Time is defined as Eastern Standard Time (EST). 5 AEMO s systems record these supply values at the start of each dispatch interval. 6 The NER defines scheduled and semi-scheduled generators. AEMO

9 Changes between initial and cleared supply values differ partly because initial readings are taken at the start of the dispatch interval and cleared supply values are projected for the end of the interval. This might occur over a five-minute dispatch interval as generators circumstances change due to: Ramping up or down in response to dispatch instructions. Responses to frequency or voltage events. Equipment malfunctions. Compliance issues. Weather conditions. Typically, AEMO reports on cleared supply values when presenting historical information in its planning documents such as the Electricity Statement of Opportunities, Victorian Annual Planning Report, and National Transmission Network Development Plan. This ensures consistency across a range of parameters such as spot prices, network constraint behaviour, generation outputs, and interconnector flows. These cleared supply values are distinct from the settlements data used in other South Australian Advisory Functions reports. Given this, it may be misleading to compare results that have used different data sets. Unless stated otherwise, all data presented in this report is based on data from AEMO s dispatch systems as discussed above. The exception is rooftop photovoltaic (PV), which is an estimate from the 2014 National Electricity Forecast Report (NEFR). 7 7 Available at: Viewed 7 July AEMO

10 3 HISTORICAL GENERATION 3.1 Generation changes Table 1 sets out the energy generated from scheduled, semi-scheduled, and listed non-scheduled South Australian market generators from to Only the analysis in Sections 3.2 and 3.4 includes small non-scheduled generator data. As outlined in Table 1, the following key changes occurred from to : Total generation from South Australian power stations decreased by 8% (1,060 GWh). Total gas generation decreased by 18% (1,233 GWh). Total wind generation increased by 9% (312 GWh). Total coal generation decreased by 6% (138 GWh). Total diesel generation decreased by 25% (1 GWh). Interconnector imports have increased concurrent with the reduction in South Australian electricity generation. Section 4.1 provides further details on these inter-regional changes. South Australian electricity consumption also decreased from to Table 1: Historical energy generation for South Australian power stations (GWh) a Fuel type Scheduled generators Dry Creek Gas 9 Hallett GT Gas 27 Ladbroke Grove Gas 191 Mintaro Gas 8 Northern Coal 3,546 Osborne Gas 1,181 Pelican Point Gas 2,979 Playford B Coal 1,013 Port Lincoln GT Diesel 2 Quarantine Gas 295 Snuggery Diesel 2 Torrens Island A Gas 441 Torrens Island B Gas 1, ,943 2,729 2,238 2,100 1,044 1,179 1,363 1,471 2,939 2,605 2,976 1, ,680 1,883 1,665 1,363 8 AEMO. The South Australian Historical Market Information Report (Sections 3.1 and 3.3) excludes small non-scheduled generation except where specified. It reports only those scheduled, semi-scheduled, and non-scheduled generators that are recognised by AEMO s dispatch system, and have energy data stored within AEMO s Electricity Market Management System (EMMS). Other small non-scheduled generators included in Sections 3.2 and 3.4 stored in Market Settlements and Transfer Solutions (MSATS). 9 AEMO NEFR. Available at: Viewed 7 July AEMO

11 Fuel type Semi-scheduled generators Clements Gap Wind 164 Hallett 1 (Brown Hill) Wind 336 Hallett 2 (Hallett Hill) Wind 248 Hallett 4 (North Brown Hill) Wind - Hallett 5 (The Bluff) Wind - Lake Bonney 2 Wind 296 Lake Bonney 3 Wind - Snowtown Wind 359 Waterloo Wind - Non-scheduled generators Angaston Diesel 0.5 Canunda Wind 118 Cathedral Rocks Wind 186 Lake Bonney Wind 174 Mount Millar Wind 179 Starfish Hill Wind 88 Wattle Point Wind Total 13,799 13,946 12,925 12,494 11,434 a. Dashes (-) in the table indicate that the generator was not registered during that financial year. 3.2 Generation by fuel type Figure 4 shows energy generated in South Australia by fuel type from to This includes generation from: All scheduled generators. All semi-scheduled and non-scheduled wind farms. Other market non-scheduled generators. Rooftop PV (as calculated in the 2014 NEFR). 10 Figure 4 also shows net energy imported over the Heywood and Murraylink interconnectors. Generation from small diesel, landfill methane, and hydro generators is categorised as other. 10 The rooftop PV generation calculation methodology is published in the NEFR Methodology Information Paper. Available at: AEMO

12 Technology share SOUTH AUSTRALIAN HISTORICAL MARKET INFORMATION REPORT Figure 4 shows that the following key changes occurred from to : A continued decline in coal generation. An increase in wind generation, except in An increase in rooftop PV generation. An increase in net import interconnector flows since In , South Australia s reliance on electricity generation by fuel type as a percentage of total (generated plus the energy imported) was: 40% on gas, a reduction of 7 percentage points since % on wind, an increase of 3.2 percentage points since % on coal, a reduction of 0.4 percentage points since % on rooftop PV, an increase of 1.7 percentage points since % on diesel, small hydro, and landfill methane (combined as other in Figure 4), unchanged since Figure 4: South Australian energy generation by fuel type 50% 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% Financial year Coal Gas Wind Interconnectors Rooftop PV Other 11 Rooftop PV generation has now been included based on figures calculated in the 2014 NEFR. AEMO

13 Registered capacity (MW) SOUTH AUSTRALIAN HISTORICAL MARKET INFORMATION REPORT Figure 5 shows the registered generation capacity by fuel type as at 30 July 2000, compared to that installed in South Australia as at 1 July It shows that in 2000, over 50% of South Australian generation capacity relied on gas, with coal and interconnector flows made up most of the balance. 12 By comparison, in 2014 gas makes up 44% of the state s registered generation capacity, with wind capacity (at nearly 20%) providing more capacity than coal. 13 Interconnector import capacity is 9.5% 14 and rooftop PV capacity is just below 10%. Figure 5: Registered capacity by fuel source, 2000 compared to , , , , , , Gas Wind Coal Interconnectors Rooftop PV Diesel Landfill methane / Landfill gas Water Heywood Interconnector s transfer capacity is expected to increase from a nominal 460 megawatt (MW) to 650 MW from July This follows a regulatory investment test for transmission (RIT-T) conducted by AEMO and ElectraNet and in September 2013 the Australian Energy Regulator determined that the preferred option satisfied the RIT-T The registered capacity used in Figure 4, was sourced from the ESIPC 2000 Annual Planning Review, September Available from AEMO. Viewed: 7 July Depending on weather conditions, at any particular time, the available wind generation capacity may be higher or lower than the coal capacity. 14 ElectraNet. June South Australian Transmission Annual Planning Report. Page 23. Available: Viewed: 7 July Details of the RIT-T, including the analysis and resulting assessment, are available at: Investment-Tests-for-Transmission/Heywood-Interconnector-RIT-T. Viewed 7 July AEMO

14 Emissions (MtCO2-e) SOUTH AUSTRALIAN HISTORICAL MARKET INFORMATION REPORT 3.3 Greenhouse gas emissions Figure 6 illustrates the level of greenhouse gas emissions in MtCO2-e produced from South Australian electricity generation, and the emissions associated with electricity imported into South Australia from the NEM. This assumes that import emission levels are the same as the NEM average (excluding South Australia). 16 Figure 6: Greenhouse gas emissions for South Australia per financial year Financial Year Emissions from South Australian generation Emissions from imports AEMO used updated thermal efficiencies and emission factors 17 for each generating unit to calculate the financial year emissions. Table 2 shows that South Australian greenhouse gas emissions have reduced over the last five financial years. It shows emissions for the past five financial years using the previous and new thermal efficiencies and emission factors. The previous and new thermal efficiencies and emission factors show that total emissions have reduced by 7% from to Factors affecting the decline in South Australian emissions include: Increased wind generation and reduced coal generation. Lower electricity consumption in NEM regional emission data is available in the NEM Historical Market Information Report. Available at: To be published in August All assumptions and inputs used for AEMO s planning studies are available at: Information/Planning-Assumptions. Viewed 7 July AEMO

15 Table 2: Annual emission comparison, current versus previous thermal efficiencies and emission factors Annual emissions (MtCO2-e) Previous thermal efficiencies and emission factors New thermal efficiencies and emission factors Difference between the two methodologies 7.07% 7.91% 6.67% 6.98% 7.29% AEMO calculated state-based emissions using actual annual generation for South Australian power stations, and thermal efficiencies and emission factors for each generator. AEMO calculated interconnector emissions using net annual interconnector imports, an emission factor based on annual generation from all NEM power stations (excluding those in South Australia), and thermal efficiencies and emission factors for each generating unit Capacity factors Figures 7 and 8 show a gradual decline in the annual capacity factors for South Australian generation based on each power station s historical registered capacity. These capacity factors are based on the full financial year generation output. Newly constructed generating systems that did not operate for the full financial year were pro-rated for the first year of operation. This gives a more representative annual capacity for each generating system and should facilitate direct comparison with future annual capacity factors. Note that some generators may be affected by network and other constraints that could lower their capacity factors. Generally, generating systems that respond to peak demand have lower capacity factors as they operate for short time periods and are idle most of the year. Generating systems that provide base-load electricity typically have higher capacity factors, and power continuously unless shut down for maintenance. Changes of note between the and capacity factors are: Higher capacity factors for most gas-powered peaking plants, and lower capacity factors for base-load coal and gas-fired generators. Northern Power Station s capacity factors for the most recent two years reduced from 59% to 45% from to This is due to Alinta Energy changing the way it operates Northern and Playford. 19 Capacity factors for all wind farms are higher than last year. Figures 9 to 12 show the capacity factors for both summer (defined as 1 November to 31 March) and winter (defined as 1 June to 31 August). They highlight the different seasonal operating patterns for specific generators. 18 The South Australian Government requested AEMO uses this methodology in this report. This is different from the way AEMO calculates emissions in other reports. 19 Alinta Energy advised: Northern will only be available if recalled (with a recall time of up to three weeks) from 1 April 2013 to 30 September 2013 and from 1 April 2014 to 30 September After 1 October 2014, the power station will return to normal service. Summer operation will continue as normal. Playford B power station will be available with a recall time of around 90 days. Source: Generation Information Pages. Available: Viewed 30 May AEMO

16 AEMO Figure 7: Financial year capacity factors for scheduled generators 100% 90% 80% 70% Capacity factor (%) 60% 50% 40% 30% 20% 10% 0% Dry Creek Hallett GT Ladbroke Grove Mintaro Northern Osborne Pelican Point Playford B Port Lincoln GT Quarantine Snuggery Torrens Island A % 1.7% 27.3% 1.0% 76.4% 74.9% 71.2% 48.2% 0.3% 15.0% 0.4% 10.5% 24.2% % 1.4% 19.6% 0.3% 84.9% 66.2% 70.2% 15.1% 0.3% 6.9% 0.1% 16.0% 24.0% % 0.5% 11.5% 0.7% 58.6% 74.6% 62.1% 13.2% 0.1% 3.3% 0.1% 12.3% 26.8% % 3.7% 13.2% 1.6% 48.2% 86.5% 71.1% 0.0% 0.2% 7.7% 0.0% 10.5% 23.8% % 2.1% 33.1% 1.0% 45.2% 93.3% 44.1% 0.0% 0.1% 12.3% 0.0% 8.0% 19.4% Torrens Island B

17 AEMO Capacity factor (%) Figure 8: Financial year capacity factors for non-scheduled and semi-scheduled generators (wind farms) 50% Non-scheduled wind farms Semi-scheduled wind farms 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% Canunda Cathedral Rocks Lake Bonney Mount Starfish Hill Millar Wind Farm Wattle Point Wind Farm Clements Gap Wind Farm Hallett 1 (Brown Hill) Hallett 2 (Hallet Hill) Hallett 4 (North Brown Hill) Hallett 5 (The Bluff) Lake Bonney 2 Lake Bonney 3 Snowtown % 32.2% 24.7% 29.1% 29.0% 33.0% 32.9% 40.5% 39.6% 0.0% 0.0% 21.3% 0.0% 41.4% 0.0% % 30.6% 26.0% 29.7% 24.4% 32.8% 33.8% 38.8% 39.2% 27.6% 0.0% 26.0% 24.9% 40.0% 27.3% % 31.8% 28.5% 30.6% 28.1% 34.0% 35.1% 40.0% 40.8% 39.5% 28.9% 27.6% 25.4% 43.3% 32.0% % 30.2% 27.0% 30.2% 22.4% 31.1% 33.6% 40.1% 41.1% 36.8% 33.7% 27.5% 28.0% 43.3% 32.2% % 34.0% 29.2% 33.2% 31.1% 37.0% 35.3% 42.3% 41.1% 40.9% 36.4% 30.2% 29.9% 45.1% 34.9% Waterloo

18 AEMO Capacity factor (%) Figure 9: Summer capacity factors for scheduled generators 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Dry Creek Hallett GT Ladbroke Grove Mintaro Northern Osborne Pelican Point Playford B Port Lincoln GT Quarantine Snuggery Torrens Island A % 3.8% 29.8% 1.8% 87.7% 71.0% 75.7% 51.0% 0.7% 17.5% 1.1% 7.2% 24.2% % 2.7% 19.1% 0.4% 89.7% 61.1% 69.7% 22.6% 0.5% 6.2% 0.1% 15.0% 23.1% % 0.4% 8.7% 0.5% 60.0% 72.5% 65.6% 17.6% 0.1% 1.9% 0.0% 8.0% 26.7% % 0.8% 5.6% 0.7% 82.7% 84.0% 73.8% 0.0% 0.2% 6.8% 0.1% 7.3% 21.2% % 3.1% 25.3% 1.0% 62.4% 98.4% 47.3% 0.0% 0.3% 9.4% 0.0% 7.3% 20.1% Torrens Island B

19 AEMO Capacity factor (%) Figure 10: Summer capacity factors for non-scheduled and semi-scheduled generators (wind farms) 50% Non-scheduled wind farms Semi-scheduled wind farms 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% Canunda Cathedral Rocks Lake Bonney Mount Starfish Hill Millar Wind Farm Wattle Point Wind Farm Clements Gap Wind Farm Hallett 1 (Brown Hill) Hallett 2 (Hallet Hill) Hallett 4 (North Brown Hill) Hallett 5 (The Bluff) Lake Bonney 2 Lake Bonney 3 Snowtown % 29.8% 21.6% 28.0% 27.9% 34.0% 37.9% 34.0% 32.9% 0.0% 0.0% 23.4% 0.0% 42.0% 0.0% % 36.2% 27.0% 33.5% 32.8% 42.7% 36.2% 36.3% 36.8% 35.3% 0.0% 23.2% 22.6% 42.4% 32.1% % 30.2% 26.5% 30.4% 32.0% 38.4% 40.0% 37.0% 37.2% 39.7% 30.8% 27.1% 26.1% 46.8% 30.7% % 31.1% 25.4% 30.7% 17.9% 35.8% 36.3% 37.6% 37.8% 36.3% 30.1% 26.4% 27.2% 44.9% 29.1% % 32.1% 22.7% 32.1% 31.4% 39.2% 38.3% 34.9% 33.5% 36.4% 27.6% 24.5% 24.6% 46.3% 28.7% Waterloo

20 AEMO Capacity factor (%) Figure 11: Winter capacity factors for scheduled generators 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Dry Creek Hallett GT Ladbroke Grove Mintaro Northern Osborne Pelican Point Playford B Port Lincoln GT Quarantine Snuggery Torrens Island A % 0.4% 20.5% 0.0% 93.3% 79.0% 74.5% 38.3% 0.1% 3.2% 0.0% 3.5% 26.0% % 0.6% 25.1% 0.1% 77.4% 79.2% 79.3% 38.5% 0.1% 11.4% 0.0% 21.0% 23.9% % 0.3% 17.9% 0.0% 48.1% 82.2% 66.2% 0.0% 0.0% 1.9% 0.0% 23.1% 26.0% % 0.3% 21.0% 0.3% 35.3% 91.1% 78.3% 0.0% 0.3% 5.2% 0.0% 13.1% 36.3% % 6.6% 20.7% 2.0% 19.8% 80.3% 49.5% 0.0% 0.1% 18.3% 0.0% 24.3% 22.3% Torrens Island B

21 AEMO Capacity factor (%) Figure 12: Winter capacity factors for non-scheduled and semi-scheduled generators (wind farms) 60% Non-scheduled wind farms Semi-scheduled wind farms 50% 40% 30% 20% 10% 0% Canunda Cathedral Rocks Lake Bonney Mount Starfish Hill Millar Wind Farm Wattle Point Wind Farm Clements Gap Wind Farm Hallett 1 (Brown Hill) Hallett 2 (Hallet Hill) Hallett 4 (North Brown Hill) Hallett 5 (The Bluff) Lake Bonney 2 Lake Bonney 3 Snowtown % 39.9% 33.4% 38.1% 35.7% 37.2% 19.9% 56.8% 47.5% 0.0% 0.0% 25.5% 0.0% 46.9% 0.0% % 30.2% 29.8% 30.5% 21.5% 30.8% 31.3% 41.6% 42.6% 1.1% 0.0% 26.4% 20.1% 38.7% 2.2% % 35.2% 35.0% 33.7% 24.6% 32.4% 32.6% 45.4% 46.0% 42.3% 6.5% 32.1% 30.6% 40.6% 35.1% % 33.2% 33.5% 32.6% 30.0% 34.4% 32.3% 49.8% 53.0% 38.7% 43.7% 32.3% 33.2% 44.8% 41.1% % 36.7% 35.9% 37.2% 30.0% 37.2% 19.8% 29.7% 29.4% 25.9% 26.3% 22.6% 23.8% 26.5% 22.3% Waterloo

22 4 INTER-REGIONAL SUPPLY 4.1 Historical interconnector flows Tables 3, 4, and 5 show the total energy imported and exported, and the average power flows for the Heywood and Murraylink interconnectors. Import is defined as the energy flow from Victoria to South Australia, and export as energy flow from South Australia to Victoria. In combined interconnector total imports (Table 5) increased by 13% compared to , total exports decreased by 11%, and combined net interconnector imports increased by 19%. These results possibly reflect cheaper interstate supply and decreased availability of coal generation in South Australia. Table 3: Historical Heywood Interconnector power flow Financial year Total imports (GWh) Total exports (GWh) Import average (MW) Export average (MW) , , , , , , , , Table 4: Historical Murraylink Interconnector power flow Financial year Total imports (GWh) Total exports (GWh) Import average (MW) Export average (MW) AEMO

23 Table 5: Total interconnector power flow Financial year Total imports (GWh) Total exports (GWh) Net imports (GWh) , , , , , , , , , , , , ,673 From , a combination of factors led to changes in the supply mix, including: More expensive interstate supply. Drier or drought conditions affecting interstate hydro generation supplies. An increase in wind farm construction. Figure 13 shows total imports and exports into South Australia from to Energy imported into South Australia from Victoria during the year is plotted in the orange column bars above the 0 GWh line (x-axis), and energy exported from South Australia to Victoria is shown below the line. AEMO

24 GWh SOUTH AUSTRALIAN HISTORICAL MARKET INFORMATION REPORT Figure 13: Total interconnector net imports 3,000 2,500 2,000 1,500 1, , Financial Year Imports (flows from Victoria to South Australia) Exports (flows from South Australia to Victoria) 4.2 Average interconnector flow patterns Figure 14 shows annual flow patterns for combined interconnector imports (from Victoria to South Australia). On average, net interconnector imports are high during the day and are low (or exporting) overnight. A dip in imports occurs at around pm when Victorian hot water systems switch on. Conversely, a peak in imports occurs around pm market time (11.00 pm South Australian time) when South Australian overnight hot water systems switch on. Figure 15 provides a breakdown of the interconnector flow patterns for showing that, on average, Heywood tends to import electricity from Victoria, whereas Murraylink import and export flow is similar. Figures 16 and 17 outline interconnector flow averages for each five-minute dispatch interval of each day ov er the past three years for business days in summer and winter. Note that the winter 2014 curve only includes data for the month of June AEMO

25 Interconnector flow (MW) Interconnector flow (MW) SOUTH AUSTRALIAN HISTORICAL MARKET INFORMATION REPORT Figure 14: Combined interconnector daily 5-min average flow Time of day (NEM time) Figure 15: Heywood, Murraylink and combined interconnector daily 5-min average flow Time of day (NEM time) Average of Heywood Average of Murraylink Average of Combined AEMO

26 Interconnector flow (MW) Interconnector flow (MW) SOUTH AUSTRALIAN HISTORICAL MARKET INFORMATION REPORT Figure 16: Combined interconnector summer daily 5-min average flow (business days only) Time of day (NEM time) Summer Summer Summer Figure 17: Combined interconnector winter daily 5-min average flow (business days only) Time of day (NEM time) Winter 2012 Winter 2013 Winter 2014 (to 30 June 2014) AEMO

27 4.3 Flow duration curves Flow duration curves are a graphical representation of the frequency of power being transferred via interconnectors. Lines above the x-axis indicate imports from Victoria into South Australia. The area between the curves and the x-axis represents the amount of energy being transferred between these regions. Flow duration curves indicate interconnector utilisation. Heywood and Murraylink have a nominal import capability of 460 MW and 220 MW respectively, and a combined nominal import capability of 680 MW. 20 Note that under certain conditions the interconnectors can exceed the maximum nominal import capability for brief periods; this typically depends on the short-term equipment ratings. Figures 18 and 19 show flow duration curves for the Heywood and Murraylink interconnectors over the past three years. The stepped flow duration curves for Murraylink reflect its banded transfer constraints. As Figures 18 and 19 illustrate, in the Heywood Interconnector s capacity (460 MW) was 100% for 6.6% of the time, only slightly less than in when it was utilised for 8.5% of the time. By comparison, in , the maximum electricity flow along the Heywood Interconnector was 457 MW, which was maintained for less than 0.5% of the time. Figure 20 shows the combined Heywood and Murraylink electricity flows. In , South Australia increased its net import from Victoria compared to previous years. Figure 21 shows interconnector utilisation as a percentage of total transfer capability. This indicates that transfers over the Heywood Interconnector are closer to its total capability compared to Murraylink. 20 ElectraNet. South Australian Transmission Annual Planning Report June Available at: Papers/2014TAPR.pdf. Viewed: 7 July AEMO

28 Figure 18: Heywood Interconnector flow duration curves Figure 19: Murraylink Interconnector flow duration curves AEMO

29 Figure 20: Combined interconnector flow duration curves Figure 21: Interconnector flow as a percentage of interconnector capacity AEMO

30 5 LINKS TO SUPPORTING INFORMATION Information source AEMO Generator Information page AEMO South Australian Advisory Functions NEM Historical Market Information Report Website address (to be published in August 2014) AEMO

31 MEASURES AND ABBREVIATIONS Units of measure Abbreviation GWh MW MtCO2-e Unit of measure Gigawatt-hour Megawatts Megatonnes of carbon dioxide equivalent Abbreviations Abbreviation AEMO ESOO MSATS NEFR NEM PV RIT-T Unit of measure Australian Energy Market Operator Electricity Statement of Opportunities Market Settlements and Transfer Solutions National Electricity Forecasting Report National Electricity Market Photovoltaic Regulatory Investment Test for Transmission AEMO