Wind and Batteries Set New Records on Australia's Main Grids in April

In April, Australia's main electricity grids experienced a remarkable shift in generation patterns, with strong wind conditions significantly reducing coal-fired power output and large-scale batteries displacing gas peaking plants. These developments set multiple new records, highlighting the accelerating transition toward renewable energy and storage in the country's energy mix.

Record-Breaking Winds Reshape the Generation Mix

Favorable weather patterns led to strong and sustained wind speeds across key regions, enabling wind farms to achieve unprecedented penetration levels on both the National Electricity Market (NEM) and the South West Interconnected System (SWIS). On multiple days, wind energy supplied over 50% of the total electricity demand in certain states, pushing coal plants to ramp down or even shut off entirely. This marks a significant milestone for the industry, as wind power continues to emerge as a baseload competitor.

Coal Takes a Hit

The surge in wind generation directly impacted coal-fired power stations. Several plants experienced negative or near-zero output during peak wind hours, as grid operators prioritized cheaper, cleaner wind energy. This crunched coal's market share, with April setting a record for the lowest monthly coal generation share in NEM history. The trend underscores the growing economic pressure on ageing coal plants, which struggle to compete with near-zero marginal cost renewables.

Gas Peakers Lose Ground to Batteries

Simultaneously, large-scale battery installations achieved a new milestone by outperforming gas peaking generators during evening demand peaks. Batteries dispatched stored energy faster and more reliably than gas turbines, capturing a larger portion of the peaking market. This month-on-month displacement is a clear signal that battery storage is becoming a viable alternative to flexible gas generation, offering rapid response times and zero emissions.

Battery Storage Sets New Benchmarks

April saw multiple battery complexes, including the Hornsdale Power Reserve and the Victorian Big Battery, set new records for charge and discharge cycles. Combined, they provided enough capacity to meet peak demand for several hours, outperforming equivalent gas capacity. The economic case for batteries has strengthened with falling storage costs and improved market mechanisms, such as the new fast frequency response ancillary services.

• Record daily discharge volumes and revenue
• Highest-ever participation in frequency regulation markets
• Reduced reliance on gas-powered contingency reserves

Implications for Australia's Energy Transition

These records are not merely statistical anomalies—they represent a structural shift. The simultaneous collapse of coal output during high renewable availability and the displacement of gas by batteries indicate a future where fossil fuel generation becomes increasingly sidelined. Policymakers and market operators must now adapt infrastructure planning, grid management, and investment incentives to accommodate this rapid transition. The April data also underscores the importance of continued investment in transmission and storage to maintain reliability as renewable penetration grows.

In summary, the month of April delivered a clear demonstration of the power of wind and batteries to reshape Australia's electricity grids. With coal and gas both losing ground to cleaner, cheaper alternatives, the nation moves one step closer to a fully decarbonized energy system.