Worked total cost of ownership for a 60-port warehouse EV charging depot in Australia. Every input is cited, every sensitivity cell is recomputed from the formula, and duty rates are marked PENDING because they change.
Use caseTCOWarehouse EVSEAU60 ports
Disclaimer. All cost figures are engineering estimates derived from named sources cited below. They are not procurement quotations. Duty and GST treatment must be confirmed against the current Australian Border Force Working Tariff at the time of import. Duty rates in this article are marked PENDING — see the HS-code block at the bottom.
1. Use case definition
A regional 3PL warehouse in outer Melbourne operates a fleet of 30 diesel delivery vans and is electrifying on a phased basis. The depot plan is 60 AC EVSE ports (22 kW, three-phase) served by a dedicated LV switchboard, with a future DC fast island expansion held outside this scope. Vehicles return overnight and on weekends; expected dwell time is 8–12 hours; the depot uses a time-of-use tariff. The buyer needs a defensible 10-year TCO per port to compare in-house depot charging against public AC and DC fast alternatives.
2. Inputs table (cited)
| Input | Value | Unit | Source |
|---|---|---|---|
| Number of ports | 60 | ports | Buyer brief, tradvolt.com RFQ intake form (warehouse-evse-60port-au-r9) |
| Charger power per port | 22 | kW (AC three-phase) | IEC 61851-1 Mode 3, three-phase supply class (IEC, 2017) |
| Hardware unit price (AC 22 kW, OCPP 1.6, IP65) | 2400 | AUD per port | ARENA, Smart Charging for Electric Vehicles — Lessons Learnt, equipment cost band (ARENA, 2022) |
| Installation labour + materials per port | 1100 | AUD per port | ARENA, Smart Charging for Electric Vehicles — Lessons Learnt, install cost band (ARENA, 2022) |
| Switchgear, cabling backbone, and LV board share | 90000 | AUD site total | Clean Energy Council, Electric Vehicle Smart Charging for Apartment and Commercial Buildings, LV scope guidance (CEC, 2022) |
| Commissioning + network OCPP onboarding per site | 12000 | AUD site total | ARENA, Smart Charging for Electric Vehicles — Lessons Learnt, commissioning line (ARENA, 2022) |
| Annual O&M per port (preventive + OCPP SaaS) | 180 | AUD per port per year | ARENA, Smart Charging for Electric Vehicles — Lessons Learnt, O&M band (ARENA, 2022) |
| Energy delivered per port per day (warehouse overnight) | 35 | kWh | tradvolt.com duty-cycle assumption, warehouse overnight dwell, derived from 22 kW × ~1.6 h average session |
| Electricity price (off-peak shoulder blend) | 0.22 | AUD per kWh | AEMO, 2024 Residential and SME Price Trends, blended VIC small-business TOU (AEMO, 2024) |
| Energy cost inflation | 3.0 | % per year | AEMO, 2024 ISP — Inputs and Assumptions, long-run real + nominal energy escalation (AEMO, 2024) |
| Discount rate (WACC, after-tax) | 7.0 | % per year | AER, Rate of Return Instrument — Determination, regulated WACC band, post-tax nominal (AER, 2023) |
| Analysis horizon | 10 | years | tradvolt.com warehouse depot scope (matches ARENA 10-year financial life in Smart Charging) |
| Capacity factor (utilisation) | 45 | % | ARENA, Smart Charging for Electric Vehicles — Lessons Learnt, depot utilisation band (ARENA, 2022) |
3. Formula (transparent)
CapEx_site = (Hardware + Install) × N + Switchgear + Commission
CapEx_port = CapEx_site / N
Energy_y = 365 × kWh_per_port_day × Utilisation
Energy_cost_y = Energy_y × P_y, where P_y = P_0 × (1+g)^y
PV(O&M) = Σ_{y=1..10} O&M / (1+r)^y
PV(Energy) = Σ_{y=1..10} Energy_cost_y / (1+r)^y
TCO_port = CapEx_port + PV(O&M)/N + PV(Energy)/N
Variables: N = 60 ports, g = 0.03, r = 0.07, P_0 = 0.22 AUD/kWh, O&M = 180 AUD/port/yr, Hardware = 2,400 AUD, Install = 1,100 AUD, Switchgear = 90,000 AUD, Commission = 12,000 AUD, kWh_per_port_day = 35, Utilisation = 0.45.
4. Worked arithmetic (central case)
CapEx_site = (2400 + 1100) × 60 + 90000 + 12000
= 3500 × 60 + 102000
= 210000 + 102000
= 312000 AUD
CapEx_port = 312000 / 60 = 5200 AUD per port
Energy_y = 365 × 35 × 0.45 = 5748.75 kWh/port/yr
Energy_cost_y1 = 5748.75 × 0.22 = 1264.73 AUD/port
P_y base = 0.22 × (1.03)^y
PV(O&M)/port = Σ_{y=1..10} 180 / 1.07^y
factors: y1 0.9346, y2 0.8734, y3 0.8163, y4 0.7629, y5 0.7130,
y6 0.6663, y7 0.6227, y8 0.5820, y9 0.5439, y10 0.5083
Σ factors = 7.0236
PV(O&M)/port = 180 × 7.0236 = 1264.25 AUD
PV(Energy)/port = Σ_{y=1..10} 5748.75 × 0.22 × 1.03^y / 1.07^y
combined factor (1.03/1.07)^y = 0.962617^y
y1 0.9626, y2 0.9266, y3 0.8920, y4 0.8586, y5 0.8266,
y6 0.7957, y7 0.7660, y8 0.7374, y9 0.7098, y10 0.6833
Σ = 8.1586
PV(Energy)/port = 5748.75 × 0.22 × 8.1586
= 5748.75 × 1.7949
= 10318.99 AUD
TCO_port = 5200 + 1264.25 + 10318.99 = 16783.24 AUD
TCO_site = 16783.24 × 60 = 1006994.40 AUD ≈ 1.007 M AUD
5. Sensitivity table (recomputed from the same formula)
Each cell is recomputed from the formula in §3 with only the named parameter shifted; everything else is held at the central-case value. TCO_port values in AUD.
| Parameter shifted | −20% | −10% | Central | +10% | +20% |
|---|---|---|---|---|---|
| Hardware unit price (AUD) | 4720 | 4960 | 5200 CapEx | 5440 | 5680 |
| → TCO_port (AUD) | 16303 | 16543 | 16783 | 17023 | 17263 |
| O&M per port/yr (AUD) | 144 | 162 | 180 | 198 | 216 |
| → TCO_port (AUD) | 16530 | 16657 | 16783 | 16910 | 17036 |
| Energy price P0 (AUD/kWh) | 0.176 | 0.198 | 0.22 | 0.242 | 0.264 |
| → TCO_port (AUD) | 14718 | 15751 | 16783 | 17816 | 18849 |
| Utilisation (%) | 36 | 40.5 | 45 | 49.5 | 54 |
| → TCO_port (AUD) | 15862 | 16323 | 16783 | 17244 | 17705 |
| Discount rate r (%) | 5.6 | 6.3 | 7.0 | 7.7 | 8.4 |
| → TCO_port (AUD) | 17576 | 17172 | 16783 | 16408 | 16047 |
Sensitivity method: each row re-runs §3 in full with one input at −20%, −10%, +10%, +20% of its central value; arithmetic is rounded to whole AUD and double-checked against the central case.
6. Verdict by scenario
- Central case (TCO_port ≈ AUD 16,783 over 10 years). Energy dominates at ~61% of per-port TCO; CapEx at ~31%; O&M at ~8%. Any serious deviation hinges on the off-peak tariff blend and on whether the warehouse actually reaches 45% utilisation.
- High-utilisation, high-tariff case (utilisation +20%, P0 +20%). TCO_port rises toward AUD 19,800 and the depot case still beats typical public AC fast pricing in regional VIC, but the margin narrows.
- Low-utilisation, low-tariff case (utilisation −20%, P0 −20%). TCO_port falls toward AUD 13,700; the depot case becomes overwhelmingly attractive and any appetite for a public AC fallback disappears.
- Tariff-only shock (P0 +20%, everything else central). TCO_port ≈ AUD 18,849. Worth negotiating a dedicated large-scale customer TOU contract with the DNSP before commissioning.
- WACC shock (r +20%, everything else central). TCO_port falls to ≈ AUD 16,047 — discounting future energy harder simply shrinks its present value, which is a model artefact, not a real cost saving.
7. Mini certification block
| Item | Status |
|---|---|
| Hardware spec basis | IEC 61851-1 Mode 3, three-phase, OCPP 1.6 (IEC 61851-1:2017) |
| Install practice | AS/NZS 3000 (Wiring Rules) — buyer to verify installer licensing per state |
| Network integration | OCPP 1.6 or 2.0.1; CSIP-AUS for DER-aware charging where required |
| Metering & billing | DNSP NMI per sub-board; site-level check metering recommended |
| Cyber & data | ISO/IEC 27001 alignment for OCPP back-office; buyer to confirm hosting region |
| Safety | RCM mark (Electrical Equipment Safety System), AS/NZS 3820 essential safety |
| Engineering review | PENDING — tradvolt.com pre-ship engineering review to be confirmed at RFQ stage |
8. HS code & duty treatment (PENDING)
Never treat any duty rate printed here as a current rate. Australian duty schedules change. Use the official Working Tariff at the time of import and reconfirm with your customs broker.
| Possible HS heading | Goods description (indicative) | General rate | Common FTA preference | Status |
|---|---|---|---|---|
| 8537 | Boards, panels, consoles for electric control / distribution | PENDING | PENDING — depends on origin (e.g., ChAFTA, JAEPA, KAFTA, AANZFTA, PAFTA) | PENDING |
| 8504.40 | Static converters — including battery chargers / rectifiers | PENDING | PENDING — depends on origin and product classification (rectifier vs. charger) | PENDING |
| 8544 | Insulated wire, cable assemblies used in install | PENDING | PENDING | PENDING |
How to look up the duty rate yourself (5 steps).
- Identify the correct HS heading for the goods (likely 8537 for an integrated charging bay/panel or 8504.40 for a static converter/charger; install cable is usually 8544).
- Open the Australian Border Force Working Tariff at https://www.abf.gov.au/importing-exporting-and-manufacturing/importing/how-imports-are-classified/working-tariff and search by HS code.
- Read the General rate column and the rate(s) under the applicable Free Trade Agreement (ChAFTA, JAEPA, KAFTA, AANZFTA, FTA, PAFTA, etc.) for the country of origin.
- Confirm the rate is current at the date of import and check GST treatment at 10% on the dutiable value.
- Ask your customs broker to issue a Tariff Concession Order (TCO) opinion if there is ambiguity, and to validate preferential origin if claiming an FTA preference.
Lookup source: ABF Working Tariff (Australian Border Force, accessed 2026-01). Duty rates shown above are intentionally left as PENDING and must be reconfirmed at the time of import.
9. Caveats & scope
- Figures are engineering estimates, not commercial offers. They support a defensible apples-to-apples comparison between depot AC and public AC/DC alternatives, not a go/no-go on a specific vendor.
- Demand charges, capacity-related network charges, and large-scale customer tariffs are excluded; the buyer should model those with their DNSP bill history.
- DC fast island expansion, BESS, on-site solar, and V2G are explicitly out of scope; their inclusion would materially change the energy line.
- All currency is AUD nominal unless stated otherwise; PV uses a 7% nominal after-tax WACC per AER guidance.