Victoria 5 MWh / 2.5 MW BESS
Investment Analysis Report
Executive Summary
This report conducts a comprehensive investment analysis for a 5 MWh / 2.5 MW containerized Battery Energy Storage System (BESS) in Victoria, Australia. The core hardware includes one 5 MWh battery container and one 40 ft integrated step-up & PCS container, with a base cost of US$870,000.
Two operating modes are compared:
- Mode 1 – Grid Charging Only: Charge from the grid during off-peak hours and discharge during peak hours to capture TOU arbitrage.
- Mode 2 – Solar Direct Charging: Add a 2.494 MWp PV array (4,300 × 580 W panels) to charge the BESS with zero-cost during daylight, then sell all energy at peak rates.
Based on 2025–2026 Victorian Default Offer TOU tariffs (Peak A$0.475/kWh, Off-peak A$0.225/kWh), key results are:
| Mode | Total CAPEX (USD) | Total CAPEX (AUD) | Payback Period | Lifecycle Net Profit (undiscounted) |
ROI | IRR |
|---|---|---|---|---|---|---|
| Mode 1 – Grid Charging | US$876,000 | A$1,331,500 | 3.81 years | A$6.33 million | 475% | 23.4% |
| Mode 2 – Solar Direct Charging | US$1,136,900 | A$1,728,000 | 1.34 years | A$14.98 million | 867% | 74.4% |
1. Project Overview & CAPEX Breakdown
| Item | Mode 1 (USD) | Mode 2 (USD) | Notes |
|---|---|---|---|
| BESS (5 MWh + PCS container) | 870,000 | 870,000 | Incl. transformer & inverter |
| PV modules (4,300 × 580 W) | – | 98,620 | ¥165/panel |
| Fixed-tilt racks | – | 65,747 | ¥110/set |
| Cables + BoS | – | 69,500 | ¥500,000 lump sum |
| Ocean freight (40 ft HC) | 6,000 (2 containers) | 33,000 (11 containers) | $3,000/container |
| Total CAPEX | US$876,000 | US$1,136,900 | 1 USD ≈ 1.52 AUD |
2. Key Assumptions
- Location: Victoria (Melbourne region, DNSP e.g. CitiPower/AusNet)
- BESS round-trip efficiency: 90 %
- Mode 2 PV-to-BESS DC efficiency: 95 % → overall system efficiency 85.5 %
- Battery cycle life: 8,000 full equivalent cycles
- Annual O&M: Mode 1 A$20,000 | Mode 2 A$30,000 (incl. PV cleaning)
- Discount rate for NPV: 6 %
- Victorian solar resource: 1,300 kWh/kWp/year (conservative)
- Taxes, land costs, civil works, and grid-connection fees are excluded
3. Victoria TOU Tariff 2025–2026
| Period | Time Window | Price (AUD/kWh) | Used by |
|---|---|---|---|
| Peak | Mon–Fri 15:00–21:00 | 0.475 | Both modes (discharge) |
| Off-Peak | All other times + weekends | 0.225 | Mode 1 only (charge) |
4. Single-Cycle / Daily Economics
| Item | Mode 1 – Grid | Mode 2 – Solar | |
|---|---|---|---|
| Charging cost per full cycle | A$1,125 | A$0 (free solar) | |
| Daily sellable energy | 4,500 kWh | ≈7,557 kWh | |
| Gross profit per day | A$1,012.5 | A$3,590 | |
| Annual gross profit | A$369,562 | A$1,316,738 |
5. Full Financial Results
| Metric | Mode 1 – Grid Charging | Mode 2 – Solar Direct |
|---|---|---|
| Total CAPEX (AUD) | A$1.3315 million | A$1.728 million |
| Annual net cash flow | A$349,562 | A$1,286,738 |
| Payback period | 3.81 years | 1.34 years |
| Lifecycle net profit (undiscounted) | A$6.33 million | A$14.98 million |
| ROI | 475% | 867% |
| NPV @ 6% | A$2.17 million | A$9.66 million |
| IRR | 23.4% | 74.4% |
6. Sensitivity Analysis
| Scenario | Mode 1 Payback | Mode 1 IRR | Mode 2 Payback | Mode 2 IRR |
|---|---|---|---|---|
| Base case | 3.81 yrs | 23.4% | 1.34 yrs | 74.4% |
| Low spread (0.45 / 0.25) | 5.8 yrs | 14.1% | 1.59 yrs | 59.2% |
| High spread (0.50 / 0.20) | 3.0 yrs | 27.9% | 1.27 yrs | 80.1% |
| 80% efficiency | 4.3 yrs | 19.7% | 1.44 yrs | 67.8% |
7. Risk & Mitigation
| Risk | Impact on Mode 1 | Impact on Mode 2 | Mitigation |
|---|---|---|---|
| Peak–off-peak spread reduction | High | Medium | Add FCAS or wholesale market revenue |
| Solar resource variability | None | Medium | Oversize PV 10–15 % + auto-cleaning |
| Battery degradation | Medium | Medium | Use Tier-1 LFP + active BMS + warranty |
| Shipping/customs delay | Low | Medium | Bulk order and early booking |
8. Final Recommendation
If you have ≥ 1 hectare of land → Choose Mode 2 (Solar + Storage)
1.34-year payback · 74.4 % IRR · A$15 million profit in 13 years
If land is limited → Mode 1 still delivers a very attractive 3.81-year payback and 23.4 % IRR
© 2025 Weltrus Energy. This document is for informational purposes only and does not constitute financial advice.
CONTACT
+86-13735502672
Adhering to the development philosophy of market-oriented, customer-centric, and supply based, we continuously promote technological innovation and product upgrades, and provide global users with higher quality, efficient, and environmentally friendly clean energy solutions.