The NEM is in the midst of a rapid buildout in battery energy storage capacity. 840 MW of new BESS, with 1680 MWh of energy storage capacity, has come online so far in 2025. This beats previous annual records after just six and a half months of the year. A further 2 GW of projects are currently in various stages of commissioning.

But in order to hit dispatchable capacity targets allowing coal retirement, much more needs to be built. So how quickly can the BESS industry deliver this?

This report explores how quickly existing projects have come online, provides data-driven benchmarks on expected timelines for construction and commissioning, and breaks down the companies involved to show who has proven the ability to deliver within these timelines.

Key takeaways

• Early projects came online quicker, but since 2021 the buildout of BESS in the NEM has ramped up without slowing construction timescales - so far.
• The average project now begins commercial operations just under 20 months from the start of construction. The fastest can achieve this 30% sooner.
• Commissioning has the largest range of uncertainty. Most projects begin commercial operations 3-4 months after construction, but some see over 2x this.
• Choosing the right delivery partners in a project matters, with three companies consistently completing construction in line with or quicker than industry benchmarks.

How long does it take to get a battery online in the NEM?

For NEM projects starting construction after April 2021, the average battery takes 16.2 months to construct, with a further 3.4 months for commissioning. This gives an average time of 19.6 months from the start of construction to commercial operations.

The fastest projects can achieve this outcome in just over 14 months. However, for the slowest it could take almost 28 - a doubling in potential timelines before a system is consistently earning revenues.