Imagine a world where nearly 90% of your electricity comes from clean, renewable sources. Sounds like a distant dream, right? Well, Western Australia just made it a reality. The South West Interconnected System (SWIS), the world’s largest isolated grid, hit a staggering 89% renewable energy generation, primarily powered by rooftop solar. But here’s where it gets even more fascinating: this milestone wasn’t just a fluke—it’s part of a larger transformation that’s challenging long-held beliefs about the stability of renewable energy grids.
On a sunny Monday morning at 11 a.m., SWIS reached 88.97% renewable energy, surpassing its previous record of 87.29% set just a day earlier. To put this in perspective, this achievement comes hot on the heels of an 85.36% peak in October. Kirsten Rose, AEMO’s executive general manager for Western Australia, attributed this success to clear skies, low energy demand, and strong wind conditions. “We’re seeing renewables consistently meet over 80% of SWIS’ electricity needs,” Rose explained, “and this trend will only grow as more renewable projects come online.”
But here’s where it gets controversial: Not long ago, skeptics argued that even 20% renewable energy would destabilize the grid, crash the economy, and send us back to the Stone Age. Some, like The Nationals, still cling to this belief. Yet, here we are, at nearly 90%, and the grid isn’t just holding up—it’s thriving.
It’s worth noting that other Australian states, like South Australia, have achieved even higher renewable shares, peaking at 150% of state demand. However, these states have a key advantage: they’re connected to interstate grids, allowing them to export excess wind and solar power. SWIS, on the other hand, operates in isolation. It can’t import or export energy, and it lacks pumped hydro—a common backup for grids heavy on renewables.
So, how is SWIS pulling this off? The answer lies in its rapidly expanding fleet of large-scale batteries, including Australia’s two biggest. These batteries play a critical role in balancing the grid, storing excess solar energy for evening peaks, and responding swiftly to disturbances. For instance, if rooftop solar generation becomes too high, these batteries can step in to stabilize the system.
Western Australia is doubling down on this transition, planning to retire its three remaining state-owned coal generators by 2029, with privately owned plants expected to follow suit. However, this ambitious goal comes with a challenge: building enough new wind and solar capacity to fill the gap. The federal government is addressing this through a WA-specific generation tender under the Capacity Investment Scheme, seeking 1.6 GW of new renewable capacity. Bids close this Friday, with winners announced next year.
And this is the part most people miss: SWIS’ success isn’t just about breaking records—it’s a proof of concept for isolated grids worldwide. If an isolated system can achieve 89% renewables without pumped hydro, what’s stopping others?
As we celebrate this achievement, it’s worth asking: Are we underestimating the potential of renewable energy? And what does this mean for the future of coal and gas? Let us know your thoughts in the comments—we’d love to hear your take on this groundbreaking development.
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