The Australian Energy Market Operator (AEMO) has released its latest Power System Requirements reference paper, outlining the technical and operational requirements for system reliability.
This paper aims to help improve understanding of the considerations that AEMO faces when managing electricity supply and demand across the National Electricity Market (NEM).
As Australia’s independent power system and market operator, AEMO said it needs to know what’s happening in real time, and also be able to anticipate what’s likely to happen in the subsequent seconds, minutes, hours, days, weeks, years and even decades.
Every five minutes, AEMO must ‘dispatch’ (initiate or enable) the market to meet demand and ancillary services using the ‘least-cost’ combination of generation (or demand response) available.
To do this, AEMO’s dispatch computer calculates an optimal solution – considering a large number of variables, parameters, limits and constraints – to respond to a security-constrained dispatch problem.
Considerations include: forecast demand and generation output, frequency and voltage limits, network constraints, and much more.
In addition, the updated Power System Requirements paper describes how the NEM power system is undergoing rapid changes.
This transformation underway involves a shift from a centralised to a decentralised system, firm to variable energy sources, synchronous to inverter-based resource generation (such a grid-scale wind and solar farms), and the rise of active consumers.
Watch AEMO’s recent NEM transformation video which captures the radical changes across the electricity grid in the last 20 years.
However, the laws of physics that determine electrical flows do not change, defining the technical attributes of the power system. These include resource adequacy, frequency, voltage and system restoration.
Some of these technical attributes have been broken down into easy-to-understand language in AEMO’s recent ‘energy explained’ campaign: system strength, frequency control, frequency and voltage.
To consistently meet the needs of the NEM power system in the face of major structural changes and resulting uncertainty across investment and operational timeframes, AEMO said it continually works with the industry to understand and address current and future system needs.
Together, these major reports outline an integrated development roadmap for the NEM and what’s needed to maintain system security in a future NEM with a high share of renewable resources.