Spain’s Blackout: A Wake-Up Call – How Australia Can Ensure Network Stability with Grid-Forming Technology

The recent blackout across Spain and Portugal serves as a stark reminder of the complexity and critical importance of grid stability in power supply systems. Within seconds, a disturbance escalated into a system-wide failure, leaving nearly 60 million people along with critical infrastructure without power.

While the full details of the incident are still emerging, the event highlights the operational challenges that come with rapidly evolving power systems. Maintaining stable frequency and synchronisation across all sources—whether traditional or renewable—is essential. A resilient grid must maintain the delicate balance between supply and demand at all times and be able to absorb disturbances.

System strength: the key ingredient

Electricity grids were historically built around synchronous generators— alternator-based machines that provide physical inertia and support frequency stability and synchronism. As alternators coupling fossil-fuelled generators to the grid retire, so too does the source of stability they once delivered. Renewable energy sources coupled through Inverter Based Resources (IBR) like wind and solar, while critical to decarbonisation, do not inherently provide these services.

The paper “Emerging Frequency Control Mechanisms in IBR Dominated Power Systems“ published in 2021 by University of Queensland researchers highlights a key tipping point: once inverter-based generation exceeds ~70% of total supply, the grid becomes vulnerable to rapid disturbances, the paper discussed how the grid can recover from a single event, but is likely to collapse when a second event happens in quick succession. The Spanish blackout followed a similar pattern with high renewable share, limited synchronous support, and cascading failure after two successive disruptions. While causation is still being investigated, the risks of operating the power network without sufficient inherent stability are well recognised.

Australia is taking steps to tackle this issue by implementing requirements around system strength remediation and emphasising the deployment of large-scale batteries coupled through IBR with grid forming capabilities. One key example of what can be achieved with the use of well-tuned state-of-the-art inverter technology was the stabilisation of the West Murray region—a formerly volatile part of the National Electricity Market (NEM)—where SMA played a crucial role in delivering inverter technology that helped restore and maintain system stability.

This achievement demonstrated how advanced inverter capabilities, when properly deployed, can resolve real-world grid challenges.

Australia has a choice—and a head start

The 2016 South Australian blackout was an early warning signal, prompting significant investment in system strength and stability. Since then, the Australian Energy Market Operator (AEMO) has become a global leader in designing frameworks to maintain grid security under high renewable penetration.

AEMO is widely recognised as best-in-class in its proactive approach to managing system strength and remediation for inertia shortfalls. Its work in establishing technical standards, forecasting renewable output, and supporting large-scale battery energy storage systems (BESS) is leading the world. Although there is a long way to go to enable the Australian electricity network to provide security of power supply while achieving the renewable energy targets, through AEMO’s pioneering work, Australia is well on its way to deliver on the promise of a decarbonised power system. Very careful consideration will be necessary in developing the technical requirements and framework to guarantee the required system strength and resilience that will enable the network to be renewable energy dominated without compromising the quality and reliability of power supply.

SMA has been at the forefront of this transition, delivering technology that actively contributes to meeting and exceeding AEMO’s stringent requirements for grid-forming capabilities. Our large-scale inverter solutions for BESS are not just aligned with AEMO’s roadmap, but they’re already being deployed to support grid stability and increase hosting capacity in areas of high renewable energy penetration.

Learning from Spain—without repeating it

Spain’s blackout illustrates what can happen when renewable integration outpaces deployment of grid support services. Australia has the tools and the institutional leadership to manage this transition. It is therefore imperative to ensure the required grid services are implemented at scale to guarantee sustainable growth of renewable energy penetration.

Grid-forming technology, paired with strategically located BESS, can serve as the backbone of a resilient, renewable energy-dominated grid. The technology to make this happen is already available and being deployed rapidly across Australia, but wider implementation is essential to keep pace with the retirement of alternator-based synchronous generation and the growth of inverter-based renewables.

A stable grid does not require choosing between renewables and reliability, it is about designing for both. Spain’s experience should not be seen as a failure of clean energy, but as a wake-up call that flags the importance of prioritising the right technologies at the relevant times: grid stability services, and ensuring the transition is grounded in sound engineering are the key to avoiding power supply disruptions.