Australian Energy Market Operator (AEMO) improved Pipeline Operational Planning with Scenario Manager

Using DNV’s Scenario Manager, AEMO bolsters energy resilience across the gas network by better identification and response to disruptions.

The operation of gas transmission systems can be dynamic, subject to the ebb and flow of demand as well as supply availability. Gas is not always easily or quickly transported to high-demand locations, and providing uninterrupted supply requires a combination of accurate data, experienced control room personnel, and the right software.

Synergi Pipeline Simulator - Scenario Manager, helps the Australian Energy Market Operator (AEMO) control room engineers ensure the transmission system is operated to satisfy peak demand and can optimally respond to supply disruptions or equipment outages.

In the State of Victoria, where Melbourne is the capital city with a population of over 5 million people, AEMO schedules the wholesale gas market and operates the gas transmission system to meet the demand of 2.2 million gas connections, maintaining system security despite sudden demand changes and gas supply disruptions is paramount. Control room engineers operate compressors and flow regulators to manage gas linepack across the 2,000 kilometer (1,250 mile) high-pressure pipeline system to manage hourly peaks in demand periods. They must swiftly adapt to sudden changes in weather driving increases in heating demand, demand spikes caused by gas fired power stations, increased gas flows to neighboring states, or gas production outages to maintain supply to customers.

Given the inherent challenges of operating a gas transmission system that experiences large demand peaks with relatively low usable linepack, engineers must conduct survival time assessments to determine which customers may be impacted, make quick and accurate system adjustments, and assess further response options including scheduling peak shaving gas. While hydraulic models serve as powerful tools for these analyses, manually running these models including inputting multiple supply and demand scenarios is time-intensive, prone to human error, and reliant on the availability of additional engineering resources.

Recognizing these challenges, AEMO initially developed an in-house predictive program. However, it lacked the complexity needed to simulate the multiple inputs and scenarios handled in the real-world control room environment. So, AEMO set out to find a comprehensive tool to help them enhance operational efficiency and reliably facilitate informed decision-making during complicated operating conditions.

worker uses SPS software

Predictive Planning Tool for Control Room Operators

AEMO made a strategic move to implement Synergi Pipeline Simulator (SPS) software in 2017. At the time, they started by leveraging the Statefinder™ module for calculating and tracking gas heating value, improving linepack estimates, and increasing the accuracy of metered flows into the distribution networks. This upgrade was essential due to the varying energy content of gas from different offshore gas production facilities, interconnected transmission pipelines that included coal seam gas, underground gas storage and peak shaving LNG storage.

Statefinder offers real-time insights into pipeline operations, providing key process calculations for heating value, gas quality tracking, inferred gas flows and linepack. Since implementing the system, AEMO has found additional benefits of the system including analysis and tracking off-specification gas, real-time model replays for planning and analysis of pigging operations during periodic in-line-inspection activities.

Pleased with the capability of Statefinder, AEMO soon adopted the Synergi Pipeline Simulator Predictor module. Predictor allows AEMO to estimate the short-term future state of the gas transmission pipeline system based on the forecasted demands and scheduled injections. The capability enables them to identify pipeline congestion and threats to customer supply early and quickly react by optimizing compressor operations and identify and validate the requirement to efficiently schedule peak shaving gas supply to customers including gas fired power stations.

Despite these advancements, AEMO recognized the need for a predictive planning tool tailored to the specific requirements of control room operations, one that seamlessly integrates various control room systems into one system. In response, DNV collaborated with AEMO to develop a cutting-edge solution: Scenario Manager.

George Giannatos AEMO

It used to take hours to run multiple scenarios, predict possible outcomes and then arrive at the best decision. Often this time was not available. Now, with Scenario Manager, this analysis can be completed in a matter of minutes. The predictions are especially helpful as we transition to different energy sources - it helps us react quickly and ensure smooth operations in times of sudden changes in demand patterns.

  • George Giannatos
  • Stream Lead Operational Systems
  • AEMO

 

With Scenario Manager, the AEMO control room can quickly analyze the impact of system events and determine the optimal course of action ranging from operational adjustments to market intervention. For instance, when faced with a producer’s inability to supply its scheduled gas quantities, the control room turns to Scenario Manager to run multiple scenarios and assess the impact of different operational decisions. Within minutes, they input parameters and access results for linepack, critical supply pressures, and system flows, aligning with forecasts for current and future demand. The control room can evaluate the outcomes of different scenarios, effectively mapping what locations will be impacted and analyzing the impact of operational adjustments on pressures at specific points in the system.

George Giannatos, Stream Lead for Operational System at AEMO says, “With Scenario Manager, we know if we're going to have insufficient linepack in a part of the system and whether or not we can maintain critical pressures with the forecast level demand, and if not, what response is appropriate. As the transmission system evolves and gas demand profiles change, we can update our DNV systems to continue to securely manage gas pipeline operations.”

pipeline

The Value of Gas Pipeline Predictions and Scenarios

AEMO faces several challenges operating the Victorian Gas Transmission System. Firstly, Victorian winter demand highly weather-dependent forecasting. Domestic and commercial heating can increase winter gas demand to more than four times the demand typically experienced outside of winter. Several gas fired power stations that are directly supplied from the transmission system can also cause short notice spikes in demand in response to events in the power system.

Secondly, two of the three transmission pipelines that supply the city of Melbourne operate bi-directionally. This bi-directional nature introduces a degree of complexity, as depending on market outcomes, linepack may not be optimally located to meet changes in gas demand, necessitating a real-time assessment of system adjustments and the time required to move gas to the demand location.

Finally, Victorian system has low linepack relative to demand. Daily demand during winter can be more than three times the gas stored in the transmission pipelines. When gas flows increase to meet winter demand, the amount of useable linepack decreases. This translates to low survival time in the event of supply interruptions, further highlighting the need for proactive management strategies and systems that enable the short notice assessment of response options.

George Giannatos summarizes, “By being able to enter and assess multiple inputs, we can assess how the system will respond within uncertainty limits. It’s an essential tool for managing the operation of the gas system. Our role is to maintain system security, and Scenario Manager enables AEMO to efficiently maintain required system pressures to supply gas users.”

The AEMO gas control room engineers rely on the easy-to-use yet powerful Scenario Manager. George explains, “Our gas operations engineers praise the increased capability of the new system, including being able to identify all the real-time system settings in Scenario Manager and the high-quality results that are produced. Now, that's a significant operational improvement on our old system where we couldn't include all the setpoints needed for optimal operation. Now, when we look at settings like back pressure control, every control parameter in the physical system is also within Scenario Manager.”

Smoothing Gas Sourcing During the Energy Transition 

Australia is currently undergoing a significant energy transition. As coal fired power stations continue to retire, gas fired power stations are being increasingly used to firm the output from wind and solar generation. The energy transition also brings a focus on emissions associated with the operation of pipeline compressors.

Looking ahead, AEMO recognizes the need to continually meet evolving market demands, including scenarios where flows in the gas system change rapidly due to a forecast decline in Victorian gas production and the increased probability of supply disruptions. George emphasizes the necessity of robust predictive models to navigate such dynamic scenarios effectively.

AEMO worked closely with DNV during the development of Scenario Manager and is continuing to engage with DNV on tailored software solutions. A new area of focus for AEMO is the integration of renewable gases from biomethane and hydrogen facilities. The emergence of these distributed connected facilities will necessitate the further development of its systems to monitor renewable gas flows including gas quality and heating values and respond to operational changes.

Profile

Customer name: Australian Energy Market Operator (AEMO) 

About AEMO: The role of the Australian Energy Market Operator (AEMO) is to manage the electricity and gas systems and markets across Australia, helping to ensure Australians have access to affordable, secure and reliable energy. Australia’s energy landscape is undergoing rapid and unprecedented levels of change. This change is being driven by an evolving power supply mix, ageing infrastructure, weather, changing technologies, consumer preferences and increasing interdependencies between gas and electricity markets. AEMO is actively driving and planning for Australia’s energy future, making sure that Australians will continue to have access to secure and reliable energy in the years to come.

Web address: https://aemo.com.au/en

Market: Independent Gas Transmission Pipeline Operator, Power System Operator, Gas & Electricity Market Operator, Electricity & Gas Planning & Forecasting, Innovation, Energy Security, Statutory Body

Solution / Product: Synergi Pipeline Simulator, Scenario Manager

Why Australian Energy Market Operator (AEMO) chose Scenario Manager:

  • Needed a robust system to manage system linepack and maintain system pressures when assessing operational responses to sudden changes in heating demand due weather conditions, gas fired power station demand, or interruptions to gas supply
  • To model the capability to respond to short notice market changes that require large flow increases in pipeline flows or flow direction changes

What AEMO gained with Scenario Manager:

  • A powerful, intuitive system that provides the ability to quickly model a scenario, evaluate its impacts and make informed decisions
  • A reliable system that provides more operational information than its in-house developed system
  • The capability to run multiple scenarios in a matter of minutes
  • Ability to run hypothetical scenarios for outcomes related to planned design and maintenance changes