BESS · Hydro Tasmania · Storage - Pumped hydro
03 Jun 2026 17:00 → 04 Jun 2026 17:00 AEST
| Capex total (greenfield) |
$2,725.71M
Shown in table How this was derived Reference |
|---|---|
| Capex refurbishment |
—
|
| Capex / MW |
$3,634,286
Shown in table How this was derived Reference |
| Capex / MWh storage |
$227,143
Shown in table How this was derived Reference |
| Fixed OPEX (annual) |
$15.80M
Shown in table How this was derived Reference |
| Fixed OPEX / MW-yr |
$21,071
Shown in table How this was derived Reference |
| Variable OPEX / MWh |
$0.00
Shown in table |
| Fuel cost / GJ |
—
How this was derived Reference |
| Heat rate GJ/MWh |
—
How this was derived Reference |
Confidence: medium · Status: ai estimated · Capex basis: estimated · AI checked 04 Jun 2026
Notes
The generator appears to correspond to Hydro Tasmania's Cethana PHES project under Battery of the Nation. Current owner material gives an estimated project cost of AUD 2.6 billion in CY2023 real dollars, not a final construction outturn; the project had not reached FID in Hydro Tasmania's December 2025 update and 2024-25 annual report. Capex per MW is calculated as AUD 2.6b / 750 MW. Capex per MWh is calculated using the EPBC referral's approximately 14,500 MWh storage figure; the user's 12,000 MWh input conflicts with official project sources stating approximately 20 hours storage, approximately 14,500 MWh or 750 MW for 20 hours. Fixed O&M and VOM are technology-default estimates from AEMO/Aurecon PHES assumptions because no Cethana-specific O&M contract or budget was found. Fixed O&M uses the closest 24-hour PHES scenario at AUD 73,500/MW-year; applied to 750 MW gives AUD 55.125m/year. Variable O&M is included in fixed O&M per Aurecon. Efficiency is the midpoint of Aurecon's 75-80% PHES round-trip efficiency range. Asset life is the midpoint of Aurecon's 80-100 year technical/design life range; major electro-mechanical refurbishment is expected at roughly 25-30 year intervals. Direct operational emissions intensity is set to 0 tCO2/MWh for a non-combustion pumped hydro storage asset, but Hydro Tasmania notes reservoir emissions quantification is an emerging issue and not fully covered by its program.
AEMO/NEM generator information identifies Battery of the Nation - Stage 2b as a 750 MW / 12,000 MWh proposed pumped-hydro project, but Hydro Tasmania's current public Cethana project materials describe the preferred Battery of the Nation pumped-hydro project as 750 MW with about 20 hours of storage, implying about 15,000 MWh. The capex and fixed opex values above are not reported project costs for Stage 2b; they are 2025 AUD estimates based on AEMO/GHD pumped-hydro cost parameters, linearly interpolated to the user's provided 16-hour duration between GHD's 10-hour and 24-hour PHES cases. Hydro Tasmania's 2019 prefeasibility Cethana option was smaller at 600 MW / 6,700 MWh and reported $900 million including contingency, about $1.5 million/MW, but this is old prefeasibility data and does not match the current 750 MW configuration. Current project status: still in approvals/business-case development; one EPBC referral was withdrawn in April 2025, but Hydro Tasmania's December 2025 update states it is working on an updated referral and that a final investment decision has not yet been made. No closure date was found; 100-year life is a technology assumption from AEMO/GHD for PHES.
The specific AEMO/NEM project record for 'Battery of the Nation - Stage 2b' lists 750 MW and 12,000 MWh, with 4 x 187.5 MW units, status publicly announced/proposed. Hydro Tasmania's current flagship pumped hydro project at Cethana is closely aligned but is described by Hydro Tasmania as 750 MW with 20 hours of storage (15,000 MWh), not 12,000 MWh. The capex value used is Hydro Tasmania's current reported Cethana estimate of $2.6 billion in CY2023 real dollars; capex_per_mwh is calculated against the user-supplied 12,000 MWh, so it differs from a calculation using Cethana's current 15,000 MWh storage capacity. O&M, efficiency and asset life are not generator-specific reported values; they are estimates/defaults based on AEMO/GHD 2025 pumped hydro assumptions, interpolated to a 16-hour / 12,000 MWh storage duration where applicable. Project remains pre-FID / approvals-stage: Hydro Tasmania says the project only proceeds if there is a strong commercial case and benefits Tasmania, with further geotechnical studies, business case analysis, approvals and Tasmanian Parliament approval still required. Major refurbishment is implicit in AEMO/GHD's 100-year technical life assumption, with regular maintenance/refurbishment assumed to maintain efficiency; no closure year was identified.
The generator record supplied by the user is 'Battery of the Nation - Stage 2b' with 750 MW and 12,000 MWh. Web research indicates Hydro Tasmania's current specific project matching this is the Cethana pumped hydro project: 750 MW and 20 hours storage, i.e. 15,000 MWh. The capex_per_mwh_aud field is calculated using the owner-reported 20-hour/15,000 MWh configuration. If the supplied 12,000 MWh registry assumption is used instead, capex is approximately AUD 216,667/MWh. Current owner estimate is AUD 2.6 billion in CY2023 real dollars; older 2019 estimates of about AUD 1.50m/MW are superseded by more detailed planning and construction-cost escalation. Fixed O&M and variable O&M are not project-specific disclosed values; they are technology default assumptions using AEMO/Aurecon PHES 24-hour storage estimates, selected as closest to the current Cethana 20-hour duration. Major refurbishment assumption is from AEMO/Aurecon: electro-mechanical major refurbishment at about 25-30 year intervals and civil design life around 100 years. No closure date found; the project is not yet at FID and, as of Hydro Tasmania's January 2026 update, remains in approvals/EIS development.