Australia's First 8-Hour Long-Duration Grid-Scale Energy Storage Plant Enters Operation

Australia has officially commissioned its first grid-scale energy storage plant designed for an 8-hour discharge duration — the RWE Limondale Battery Project near Balranald in southwestern New South Wales. This project marks a pivotal shift for the Australian grid — from short-duration frequency regulation toward long-duration energy shifting.

The facility has a capacity of 50 MW / 400 MWh and comprises 144 Tesla Megapack units. It sits adjacent to RWE's already-operational Limondale Solar Farm. Earlier this year, the project received final operational approval from the Australian Energy Market Operator (AEMO) and completed registration with the National Electricity Market (NEM), entering commercial operation.

Unlike mainstream grid batteries, the Limondale project employs an asymmetric charge/discharge design: ~100 MW charging power and 50 MW discharging power. This enables it to fully recharge in approximately four hours — efficiently absorbing abundant, low-cost midday solar generation — and then discharge steadily for eight hours, precisely covering evening peak demand and overnight load. This helps alleviate the structural supply-demand imbalance known as the 'duck curve'.

Currently, 2-hour and 4-hour battery systems dominate Australia's grid, primarily used for frequency control and short-term support. In contrast, 8-hour storage is widely regarded as a critical technology pathway for enabling high-penetration renewable energy systems and replacing coal-fired baseload generation. The Limondale project is the first long-duration storage project awarded under New South Wales' Power Infrastructure Roadmap — and benefits from government-backed revenue assurance via a long-term energy services agreement, significantly enhancing financing viability. Two additional 8-hour storage projects of identical scale are now advancing under the same mechanism.

Tesla supplied all Megapack units; Beon Energy Solutions handled balance-of-system engineering. For Tesla, this represents both another landmark project supporting Australia's new power system — and a microcosm of the rapid global expansion of its Megapack business: from a 500 MWh project in Texas to a 1 GWh project in the UK, long-duration storage is becoming one of the fastest-growing segments of its energy portfolio.