1,721,106 research outputs found
Preliminary report: black system event in South Australia on 28 September 2016
Full text linkThis preliminary report explains how severe weather moved through South Australia on the afternoon of Wednesday 28 September 2016, with high winds, thunderstorms, lightning strikes, hail, and heavy rainfall. The weather resulted in multiple transmission system faults including, in the space of 12 seconds, the loss of three major 275 kV transmission lines north of Adelaide.
Generation initially rode through the faults, but at 16:18hrs, following multiple faults in a short period, 315 MW of wind generation disconnected, affecting the region north of Adelaide. The uncontrolled reduction in generation increased the flow on the main Victorian interconnector (Heywood) to make up the deficit and resulted in the interconnector overloading.
To avoid damage to the interconnector, the automatic-protection mechanism activated, tripping the interconnector and resulting in the remaining customer load and electricity generation in SA being lost. This automatic-protection operated in less than half a second at 16:18hrs and the event resulted in the SA regional electricity market being suspended.
While the event was triggered by extreme weather, the Australian Energy Market Operator (AEMO) will conduct a thorough investigation into how each component of the electricity system responded under these circumstances. In an ever-changing environment, AEMO’s ongoing responsibility continues to be to safely and securely manage the power system and wholesale electricity markets to deliver energy security for all Australians.
AEMO will continue to analyse the events of last Wednesday and will provide a further update on Wednesday 19 October. AEMO expects that a detailed report on the SA region Black System, including recommendations, may take up to six months to complete
Preliminary report: black system event in South Australia on 28 September 2016
No full textThis preliminary report explains how severe weather moved through South Australia on the afternoon of Wednesday 28 September 2016, with high winds, thunderstorms, lightning strikes, hail, and heavy rainfall. The weather resulted in multiple transmission system faults including, in the space of 12 seconds, the loss of three major 275 kV transmission lines north of Adelaide.
Generation initially rode through the faults, but at 16:18hrs, following multiple faults in a short period, 315 MW of wind generation disconnected, affecting the region north of Adelaide. The uncontrolled reduction in generation increased the flow on the main Victorian interconnector (Heywood) to make up the deficit and resulted in the interconnector overloading.
To avoid damage to the interconnector, the automatic-protection mechanism activated, tripping the interconnector and resulting in the remaining customer load and electricity generation in SA being lost. This automatic-protection operated in less than half a second at 16:18hrs and the event resulted in the SA regional electricity market being suspended.
While the event was triggered by extreme weather, the Australian Energy Market Operator (AEMO) will conduct a thorough investigation into how each component of the electricity system responded under these circumstances. In an ever-changing environment, AEMO’s ongoing responsibility continues to be to safely and securely manage the power system and wholesale electricity markets to deliver energy security for all Australians.
AEMO will continue to analyse the events of last Wednesday and will provide a further update on Wednesday 19 October. AEMO expects that a detailed report on the SA region Black System, including recommendations, may take up to six months to complete
2016 national gas forecasting report
Full text linkThe 2016 NGFR provides insights into the increasingly complex interdependencies between the gas and electricity sectors and the relationship between Australia’s energy demand and growing links to the international gas sector.
The gas forecasts continue to be dominated by gas demand to supply liquefied natural gas (LNG) exports, with Australia (including east and west coast LNG) projected to become the world’s second largest LNG exporter by 2018, and the major LNG supplier for East Asian markets
System event report: South Australia, 8 February 2017
No full textThis report provides information on the operation of the National Electricity Market (NEM) and national power grid on Wednesday 8 February during a heatwave in eastern Australia.
AEMO will release a second report on 22 February, focused on the events of 10 February. (see related content link below)
During this heatwave period, involuntary load reduction was necessary on two occasions to preserve system security:
· On 8 February 2017 in South Australia, the power system was not in a secure operating state for over 30 minutes. AEMO directed interruption of supply to 100 megawatts (MW) of customer load in South Australia and gave clearance to restore that load 27 minutes later. Following this direction, approximately 300 MW was interrupted. The reason for the additional interruption is being investigated.
· On 10 February, in New South Wales, AEMO directed Transgrid to shed one of the Tomago Aluminium smelter potlines (290 MW), and cancelled the direction one hour later.
This report focuses on South Australia’s electricity supply on Wednesday 8 February 2017
System event report: New South Wales, 10 February 2017
No full textThis report provides information on the operation of the National Electricity Market (NEM) and national power grid in New South Wales on Friday 10 February 2017, during a heatwave in eastern Australia.
On Friday 10 February 2017, the eastern Australian states of South Australia, New South Wales, Victoria, and Queensland all experienced high summer temperatures. Temperature forecasts for New South Wales were overall lower during this day than actual temperatures.
New South Wales operational demand (energy demand provided from the grid) peaked at 1630 hours (hrs) at 14,181 megawatts (MW).
The New South Wales record peak operational demand was on 1 February 2011, and was 14,744 MW. The New South Wales Government publicly encouraged customers to reduce electricity use. AEMO observed demand reductions of approximately 200MW below forecast at the time of peak demand on 10 February 2017, which may have been due to customer responses. However, AEMO cannot measure or verify the extent of the response
Market insight report - Victoria's supply outlook
No full textThis Insights report provides a preliminary assessment of some of the potential impacts of the closure decision Hazelwood power station. Further investigation is required to gain a deeper, more holistic understanding of scenarios whereby the power system is operating with less synchronous generation
Market insight report - Victoria's supply outlook
No full textThis Insights report provides a preliminary assessment of some of the potential impacts of the closure decision Hazelwood power station. Further investigation is required to gain a deeper, more holistic understanding of scenarios whereby the power system is operating with less synchronous generation
South Australia separation event 1 December 2016: preliminary report
No full textAEMO has released its preliminary report into the South Australian separation event on 1 December 2016. The report states that at 0016 hrs (AEST) on 1 December 2016, a fault on the Moorabool to Tarrone 500kV transmission line in Victoria resulted in the South Australia (SA) electricity network being disconnected from Victoria
Update report: black system event in South Australia on 28 September 2016
No full textIn this updated report, it is now known that five system faults occurred within a period of 88 seconds on 28 September 2016, leading to six voltage disturbances.
Data now shows that nine of the 13 wind farms online at the time of the event did not ride through the six voltage disturbances, resulting in a loss of 445 MW of generation. Preliminary discussions with wind farm operators suggest this inability to ride through all disturbances was due to ‘voltage ride-through’ settings set to disconnect or reduce turbine output when between three to six disturbances are detected within a defined time period.
Thermal generators remained connected up until the SA system disconnected from the remainder of the National Electricity Market (NEM). The Heywood Interconnector remained connected up until the sudden increase in electricity flow resulting from the loss of generation caused the automatic protection mechanism to disconnect the lines.
The two contracted SRAS suppliers both experienced difficulties in providing system restart services due to two separate faults. Both facilities successfully tested their restart capacities earlier this year, so AEMO will further explore the nature of the faults experienced on 28 September 2016.
Restoration of electricity load was able to commence within three hours of the Black System event, with all load that could be restored (approximately 80-90%) being restored within a further five hours. Following the construction of temporary towers, and the restoration of three of the four damaged transmission lines, ElectraNet was able to meet all power requirements in SA from late evening on 12 October 2016.
AEMO is continuing to consult with wind farm operators and wind turbine manufacturers to better understand the impact on the power system of their ride through settings. Several wind farms have already implemented revised settings allowing them to ride through a higher number of disturbances.
AEMO returned the SA spot market to normal operation at 23:30 (AEDT) on 11 October 2016, following the formal notification that the Ministerial direction to suspend the market had been revoked.
AEMO will present a further update ahead of the December COAG Energy Council meeting, and anticipates that a detailed report on the Black System event in SA, including final recommendations, will take up to six months to complete.
AEMO acknowledges and appreciates the significant work done by generators, network service providers and others to promptly provide the data used in its analysis to date
Review of forecast accuracy metrics for the Australian Energy Market Operator
No full textThe Australian Energy Market Operator (AEMO) produces forecasts of annual electricity consumption and of minimum/maximum half-hourly demand, and must report at least annually on the accuracy of these forecasts. The University of Adelaide, School of Mathematical Sciences team were engaged to provide expert advice on the metrics used to assess forecast accuracy, as presented in the 2018 Forecast Accuracy Report (FAR) and in the internal performance monitoring dashboard (PD).Broadly, current AEMO practices are appropriate and well-supported. We provide 14 recommendations, which are summarised on the following page, including both recommendations to continue current practice, and for improvements to forecast accuracy reporting and monitoring.Forecasts of annual consumption consist of a point forecast of annual operational consumption (sent out) accompanied by point forecasts of various input drivers. AEMO's forecast assessments follow best practice and should continue in its current form (Rec. 1). Our two subsequent recommendations here (Rec. 2, 3) pertain only to communication of results, to provide additional context around the impact of input drivers.Forecasts of seasonal minimum/maximum half-hourly demand are probabilistic, summarised in the FAR by reporting 10%, 50%, and 90% Probability of Exceedance (POE) forecasts. Forecast assessment is difficult as only one seasonal minimum/maximum demand observation occurs each year. This challenge is further exacerbated by the need to communicate forecast accuracy results across non-technical audiences. AEMO currently produces qualitative analyses and summaries of the drivers of minimum/maximum demand for the 2018 FAR and the Summer 2019 Forecast Accuracy Update" these should be continued (Rec. 4), with one recommendation on the communication of these results (Rec. 5).Internally AEMO uses a range of more technical metrics to assess the accuracy of minimum/maximum probabilistic demand forecasts. Broadly, these are standard techniques for probabilistic forecast assessment, and are applied appropriately by AEMO. Specifically, for assessing probabilistic minimum/maximum demand forecasts AEMO consider both standard metrics for comparing distributions (the Mean Absolute Exceedance Probability and the Kolmogorov-Smirnov statistic) and for comparing competing forecasts (scores based on pinball loss). However, given the sparsity of available data, to construct these metrics it is necessary to produce more observations" one possible approach to this is to assess minimum/maximum demand forecasts over smaller time intervals (e.g., monthly). We recommend that the assumptions underlying this approach be carefully analysed to avoid introducing bias to the forecast assessment process (Rec. 6), and propose continued use with small modifications to these existing metrics (Rec. 7, 11). A backcasting approach was used in the 2018 FAR. We recommend that this be discontinued (Rec. 8)" it appears that AEMO has independently done so, as this approach is not present in the 2019 summer FAR update. We also recommend that backcasting be replaced with a full-season hindcasting approach (Rec. 9), and that historical simulations also continue to be used as part of forecast assessment (Rec. 10).Furthermore, we recommend that the distributions of residuals, currently used and assessed as part of the forecast development process, be incorporated more formally into the forecast assessment process through the PD (Rec. 12, 13), or similar dashboard. If the methodology used to produce probabilistic forecasts changes, these metrics should be assessed for relevance and replaced if required (Rec. 14)
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