| Grid stability
Average tenure in an organisation
Technology and system complexity
1990 2000 2010 2020
Figure 2. The decline in institutional knowledge. Source: VeriConneX
before the previous generation’s performance in real grid events can be fully assessed and incorporated into updated standards. This pattern repeats globally: deploy technology; experience grid events; analyse performance; update grid codes; repeat. Each cycle takes years, whilst technology deployment accelerates, creating an ever-widening gap between what grid codes require and what modern power systems actually need.
The disconnect between planning and reality
In planning studies, grid events are modelled with clinical precision. Generator trips are instantaneous. Protection operates exactly as specified. Operational experience consistently reveals a messier reality.
Consider the wind farm response shown in Figure 1. During a grid disturbance involving circuit breaker recloser operation — two consecutive faults within seconds — the facility’s actual behaviour demonstrates a complexity absent from planning models. Active power fluctuates throughout the event sequence in response to changing wind speed. Reactive power exhibits sharp transient responses during each fault, with magnitudes and recovery patterns that no simplified dynamic model would predict and would be challenging even for a detailed EMT (electromagnetic transient) model. Real grid events involve multiple overlapping transients, equipment and neighbouring generators responding to conditions that exist for fractions of a second, control systems reacting to rapidly changing voltage and frequency signals.
Planning studies model single, clean disturbances. Reality delivers a complex, sometimes unpredictable, sequence of events in which each system response influences the next. This disconnect represents a fundamental risk in modern power systems. When grid codes are written based on simplified models, and compliance is verified through mathematical modelling and one-time commissioning tests, the gap between assumed and actual performance during real grid stress events remains unknown — until a major disturbance reveals it. The transition from centralised power stations to more dispersed renewable generation has also dispersed technical expertise across multiple organisations, contractors, and frequently rotating personnel (Figure 2).
A few decades ago, asset knowledge was concentrated in specialist teams that understood equipment throughout its multi-decade operational life. Contemporary arrangements have made institutional knowledge more fragile despite advances in data collection and processing capabilities.
The Australian experience Australia confronted its own grid reliability challenges following the 2016 South Australia blackout.[3] The subsequent response has been systematic, including: a significant uplift in generator performance standards and assessment methodologies; the widespread deployment of grid-scale battery energy storage systems (Figure 3) and grid-forming inverters; and the redesign of operational frameworks for technical requirements such as primary frequency response.
There are also requirements for comprehensive monitoring and testing programmes demonstrating ongoing compliance with technical standards.[4] High-resolution data from actual grid events reveals patterns that planning studies miss. Continuous monitoring can identify power plants operating in incorrect control modes or with inappropriate setpoints — appearing compliant on paper but configured in ways that could result in an unstable grid. Similarly, periodic testing (eg, on plant change or every 3-5 years) provides confidence that generators can operate under stressed conditions. This approach acknowledges that assumptions about generator performance cannot remain
unchallenged for years following commissioning; there’s simply too much at stake.
Implications for grid codes and operations
Many grid codes need to be updated to manage contemporary grid realities, where inverter-based resources constitute substantial and growing proportions of generation capacity and where generator behaviour is increasingly defined by software rather than purely by equipment characteristics. Addressing these challenges requires co-ordinated improvements: Grid codes must be modernised to reflect the technical capabilities and limitations of inverter- based resources, moving beyond frameworks designed for synchronous machines. Planning studies should acknowledge that we have an integrated grid with many complex equipment types interacting and responding to each other, not isolated components behaving according to textbook models. The commissioning paradigm must extend from one-time testing to continuous compliance verification. Continuous monitoring enables identification of configuration drift and performance degradation. — problems that develop gradually over months or years but manifest catastrophically during disturbances. Equally critical is the preservation of institutional knowledge. Design decisions, operational constraints, and lessons learned from grid events must be systematically documented to ensure critical information survives personnel transitions. Finally, enhanced co-ordination between asset owners, network operators, and system operators is essential to ensure grid support capabilities are not merely specified but actively maintained throughout asset lifecycles.
Mind the gap
The gap between modelled and actual grid behaviour is not narrowing as power systems evolve. It is widening. The proliferation of inverter-based resources, increasingly complex control systems, and fragmented institutional knowledge create conditions in which the next major grid event will almost certainly reveal additional blind spots in current planning and operational practices.
The question is not whether these vulnerabilities exist — recent experiences have demonstrated that they do. The question is whether the industry will implement systematic approaches to identifying and addressing them before the next 27-second cascade demonstrates the cost of complacency.
References: [1] Spanish government, Report from the committee for the analysis of the electricity crisis of April 28th 2025, 17 June 2025
[2] ENTSO-E Expert Panel, Grid incident in Spain and Portugal on 28 April 2025, 3 October 2025
Figure 3. Battery energy storage system at the Eraring power plant site, Australia. Deployment of grid-scale battery energy storage systems such as this has become widespread in Australia since the 2016 SA blackout. Photo: Origin Energy
[3] AEMO, Black system South Australia 28 September , March 2017
[4] National Electricity Rules, Clause 4.15
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