By Phil Kreveld
The following (reported in the Australian Financial Review of 15 October) ought to focus minds of electrical energy planners:
“Major investors say an increasingly unsettling debate over climate policies is making it harder to push ahead with renewable energy generation projects, imperilling the transition away from fossil fuel power even as ageing coal assets are increasingly coming to the end of their lives. The warnings came a day after electricity and gas producers like AGL Energy said they were concerned that the economics of new developments were poor, partly because costs had risen but energy prices had not.”
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Our national problem is identifying the ‘electrical energy planners’. State jurisdictions are primarily the first port of call. Policy differences across the southeastern states make this a challenge. Meanwhile, as AGL indicated at the AFR Energy Summit ‘the economics of new developments [are] poor’. Although not specifically identified, the root cause of the increase in other than energy generation costs is lack of grid strength.
Grid strength will be one of the main topics at the CIGRE Power System Technical Performance Workshop (Melbourne, 20-21 October). The absence of top-level, coordinated grid design has been a frequent topic. The increases in transmission line costs, in particular for voltage augmentation, is also a much-visited topic and regrettably despite the excellent work done by industrial and academic engineering experts, it remains the Achilles heel in the renewable transition.
The climate wars continually misidentify the roots of policy standoffs. In few words, it’s not solar and wind generation, or batteries that are either our nirvana or the architects of our high cost, unreliable electricity supply. It’s the southeast grid, almost one wavelength in size—a radial construction of some 3000 nodes. Such a long, radial synchronous grid is a huge engineering challenge in its own right. Ensuring that voltages, phase angles, and frequency are stable throughout is an engineering challenge, irrespective of loads and generation that are connected to it. It bears no relationship to the grids of Western Europe with which we are frequently compared in the pubic forum discussions. The European grid comprises of huge meshed synchronous grids, interconnected via HVDC links. Meshed grids allow for many alternate power links.
Lack of grid strength not only limits power flow so as to maintain voltage stability, it also affects small and large signal stability of connected generators. It is true that the replacement of synchronous generation with inverter-based resources adds a large degree of complexity which can be ameliorated through the deployment of synchronous condensers.
In Australia’s case it is absolutely true that the major electrical power research bodies are watching our integration of renewable energy sources with great interest. The basically weak Australian grid adds an additional hurdle and it is the reason why the Australian Energy Market Operator has world’s first digital twin, allowing it to test the stability of generation—and loads like new high variable power-consuming data centres.
Whereas the political and energy policy discussions centre on such matters as ‘dunkelflaute’ and ‘baseload’, the real challenge to the renewable transition is discussed only in engineering fora, as mentioned above. The engineering hurdles are unique to Australia and are primarily responsible for the slowdown in connections of new generation, and more recently of data centre connections. A major bridge to cross is that of managing congestion and small signal stability. As matters stand most of that task for a grid with virtually only inverters is very much ahead of us and keenly watched by the Electric Power Research Institute (USA), the Energy Systems Integration Group (USA), and the Global Power System Transition Consortium (Europe).
Related article: ‘Dunkelflaute’ and weak grids
Essentially the transition journey will see to much experimentation in the integration of wide area control systems (WACS) comprising of groupings of nodes and an overall control system utilising physics-informed neural network (PINN) AI to provide human interface decision trees in operating the entire grid. This is a huge challenge, and Australia is in the vanguard. As matters stand, the practical execution of this will involve a major coordination project of transmission companies across multiple jurisdictions. A National Grid Construction Authority would have been very helpful.
