BESS · Hydro Tasmania · Storage - Pumped hydro
Stats window 29 May 2026 04:00 → 30 May 2026 04:00 AEST
29 May 2026 04:00 → 30 May 2026 04:00 AEST
| Capex total (greenfield) |
$4,875.00M
How this was derived Reference |
|---|---|
| Capex refurbishment |
—
|
| Capex / MW |
$6,500,000
How this was derived Reference |
| Capex / MWh storage |
$406,250
How this was derived Reference |
| Fixed OPEX (annual) |
$64.50M
How this was derived Reference |
| Fixed OPEX / MW-yr |
$86,000
How this was derived Reference |
| Variable OPEX / MWh |
$0.00
How this was derived Reference |
| Fuel cost / GJ |
$0.00
How this was derived Reference |
| Heat rate GJ/MWh |
—
How this was derived Reference |
Confidence: medium · Status: ai estimated · Capex basis: default · AI checked 04 Jun 2026
Notes
The requested AEMO-style project name 'Battery of the Nation - Stage 3b' appears in an AEMO Generation Information extract as a Hydro Tasmania proposed pumped-hydro project with 750 MW / 12,000 MWh. Public owner and EPBC materials found in search refer to the more specifically developed Cethana pumped-hydro project, also 750 MW, but with approximately 20 hours / approximately 14,500 MWh. Financial assumptions therefore use Hydro Tasmania's latest Cethana capex as the closest source-backed proxy for the Stage 3b generator, while capex_per_mwh is calculated against the user-provided 12,000 MWh storage size. Hydro Tasmania's July 2025 fact sheet reports $2.6 billion in CY2023 real dollars and states FID is still subject to commercial case, approvals and Tasmanian Parliament approval. No generator-specific fixed O&M, variable O&M or asset-life values were found publicly; these are low-confidence technology-default estimates from published PHES modelling assumptions. Major closure/refurbishment notes: no closure date because project is proposed/not online; pumped hydro schemes are typically long-lived and GHD notes a trend to upgrade, increase efficiency and rehabilitate existing schemes to extend life rather than retire them.
No exact Stage 3b-specific capex, fixed O&M or variable O&M publication was found. AEMO generation information identifies Battery of the Nation - Stage 3b as a proposed/publicly announced Hydro Tasmania pumped-hydro storage project with 4 x 187.5 MW units, 750 MW total capacity and 12,000 MWh storage. The financial assumptions above are therefore default/estimated, using AEMO/Aurecon 2024 PHES cost and O&M ranges interpolated between the 500 MW x 10 hour and 2,000 MW x 24 hour cases to approximate a 750 MW x 16 hour project. This produces an indicative capex of about AUD 6.5 million/MW and AUD 4.875 billion total. Older Battery of the Nation concept-study costs were much lower at about AUD 1.5 million/MW average in 2018 and should not be treated as current build cost. Pumped-hydro heat rate is not applicable; efficiency_pct reflects round-trip efficiency. Operational direct emissions are assumed zero for hydro/water generation, excluding emissions associated with grid energy used for pumping. Major refurbishment assumption is generic: electro-mechanical refurbishment every 25-30 years and civil design life around 100 years.
Battery of the Nation - Stage 3b appears in an AEMO-derived public register extract as a proposed 750 MW / 12,000 MWh pumped hydro project in TAS1, with no DUID and status 'Publicly Announced / Proposed'. I did not find a generator-specific business case or capex/O&M disclosure for a physical project named exactly 'Battery of the Nation - Stage 3b'. Hydro Tasmania's current named Battery of the Nation pumped-hydro flagship is Cethana, a 750 MW project with about/up to 20 hours storage and a reported cost estimate of $2.6 billion in CY2023 real dollars. Because Stage 3b and Cethana differ on storage duration in the sources, the capex_total_aud field uses the Cethana reported cost as the closest source-backed proxy but marks capex_basis as estimated for Stage 3b. capex_per_mwh_aud is calculated against the user-provided / AEMO Stage 3b storage capacity of 12,000 MWh; if calculated against Cethana's ~20-hour / 15,000 MWh basis, it would be about $173,333/MWh. O&M, efficiency and asset-life assumptions use AEMO/GHD/Entura technology defaults for pumped hydro rather than Stage 3b-specific disclosures. No closure or refurbishment plan was found; the project has not reached FID and requires approvals before proceeding.
Battery of the Nation - Stage 3b appears in AEMO/ACCC generator-list data as a publicly announced Hydro Tasmania TAS1 pumped hydro project with 750 MW and 12,000 MWh storage, but no DUID, online date, site-specific capex, fixed O&M, VOM, fuel contract, heat-rate, closure date or FID was found. The 12,000 MWh / 750 MW configuration implies 16 hours of storage. Financial assumptions are therefore estimated from the 2025 GHD/AEMO pumped hydro cost and technical parameter review by linear interpolation between the 10-hour and 24-hour PHES cases: capex $3.30m/MW at 10h and $4.08m/MW at 24h, giving $3.634m/MW and $2.726bn for 750 MW. Fixed O&M is similarly interpolated between $20,000/MW/year and $22,500/MW/year, giving $21,071/MW/year or $15.8m/year. Variable O&M is set to zero because GHD/Entura state variable O&M is not meaningful for hydropower and is included in fixed O&M. Efficiency is the midpoint of GHD's 75-80% round-trip efficiency range. Emissions intensity is direct operational emissions only and is treated as zero for water-based pumped hydro; indirect emissions depend on the electricity used for pumping. GHD capex scope is EPC/construction with dedicated grid connection and excludes water purchase/procurement, NSP transmission connection costs, owner costs and financing; land/development was reported separately and not included in the capex_total_aud above. Older Battery of the Nation concept estimates were materially lower ($1.05m-$1.5m/MW or $1.1m-$2.3m/MW in 2018) and should not be treated as current capex. Hydro Tasmania's 2024-25 annual report says current proposed major developments centre on Tarraleah redevelopment and pumped hydro at Lake Cethana, with Cethana progressing reference design, geotechnical investigations, commercialisation planning and updated environmental referral preparation before any final investment decision. This creates a naming/status warning: the generic 'Stage 3b' may be an AEMO planning entry rather than the currently prioritised named Cethana project.