Overview
Cost Summary
Total project cost for a 2× Cat 3516C (4.20 MW) behind-the-meter installation on an industrial estate with existing 11kV connection. All figures in AUD, excluding GST.
$2.33M
Total CAPEX (mid)
$350K
Contingency (15%)
$140K
Annual OPEX (mid)
$2.68M
All-In CAPEX
Basis of estimate. This is an AACE Class 4 estimate (±25-30%). Pricing is based on
Cat dealer indicative quotes (Feb 2026), published WP cost tables, and comparable WA industrial
projects. All ranges will narrow as detailed design progresses.
CAPEX 1
Equipment & Gensets
| Item | Qty | Spec / Notes | Low ($) | High ($) | Your Cost ($) | WA Suppliers |
|---|---|---|---|---|---|---|
| Cat 3516C Genset Package | 2 | 50 Hz, 2.10 MW per unit, 11kV alternator, radiator-cooled, skid-mounted | $1,400,000 | $1,800,000 | WesTrac · EPSA · Generator Power | |
| Acoustic Enclosures | 2 | Level 2 sound-attenuated weatherproof enclosures, 75 dB(A) @ 1m | $60,000 | $100,000 | Barclay Eng · Minetek · AcousTech | |
| Diesel Day Tanks | 2 | 1,000L each, mounted on skid, with fuel transfer pump & level switch | $8,000 | $14,000 | PETRO Industrial · Duntec | |
| Bulk Fuel Storage Tank | 1 | 30,000L double-skin self-bunded, AS 1940, level gauge, overfill protection | $25,000 | $40,000 | PETRO Industrial · WA Fuel · Duntec | |
| Diesel Fuel (Initial Fill) | 1 | 30,000L × $1.80/L delivered | $50,000 | $60,000 | BP · Viva Energy | |
| Equipment Subtotal | $1,543,000 | $2,014,000 | — | |||
CAPEX 2
Electrical & Protection
Connection Voltage
Standard — native 11kV
alternator
| Item | Qty | Spec / Notes | Low ($) | High ($) | Your Cost ($) | WA Suppliers |
|---|---|---|---|---|---|---|
| 11kV Switchgear Panel | 1 | 4-panel switchboard: 2× gen incomers, bus section, utility incomer. VCB, CT/VT, relays | $55,000 | $85,000 | Mayfield · ISAS · POWINS | |
| Protection Relays | 1 lot | SEL/ABB/Siemens numerical relays — O/C, E/F, reverse power, sync check, loss of mains | $15,000 | $25,000 | NEPEAN Power · Future Power WA | |
| Synchronising Equipment | 1 | Auto-synchroniser for parallel genset operation + manual sync backup | $8,000 | $12,000 | ISAS · Future Power WA | |
| 11kV Cabling | 1 lot | XLPE 3C×95mm² from gensets to switchboard (~50m × 2), terminations, glands | $18,000 | $28,000 | PRF Electrical · ISAS | |
| LV Cabling & Control | 1 lot | Control cables, CT/VT wiring, MODBUS/Ethernet to SCADA, UPS | $12,000 | $18,000 | PRF Electrical · ISAS | |
| Earthing System | 1 lot | Earth grid, earth rods, earth mat under switchgear. Lightning protection if required | $8,000 | $15,000 | Future Power WA | |
| Switchroom / E-House | 1 | Pre-fabricated containerised switchroom (6m×3m) with HVAC, fire suppression | $35,000 | $55,000 | Mayfield · Barclay Eng | |
| Metering (CT/Revenue) | 1 lot | Revenue-grade CT metering per AEMO and WP standards. SCADA RTU if required | $10,000 | $18,000 | Future Power WA · ISAS | |
| Electrical Subtotal | $161,000 | $256,000 | — | |||
CAPEX 3
Civil & Site Works
| Item | Qty | Spec / Notes | Low ($) | High ($) | Your Cost ($) | WA Suppliers |
|---|---|---|---|---|---|---|
| Site Preparation | 1 lot | Clearing, levelling, compaction (~2,500 sqm pad) | $30,000 | $50,000 | C&C Contracting · MJ Civil | |
| Concrete Pads / Foundations | 2 | Reinforced concrete genset pads (4m×8m×300mm each), vibration isolation | $40,000 | $65,000 | Impressive Concrete · Sampson | |
| Fuel Storage Bund | 1 | 110% capacity bund wall, HDPE liner, rainwater sump pump. AS 1940 | $15,000 | $25,000 | PETRO Industrial · Impressive Concrete | |
| Cable Trenching | 1 lot | HV & LV cable trenches, ducts, sand bedding, concrete covers (~100m) | $15,000 | $25,000 | C&C Contracting · Perth Works | |
| Stormwater Drainage | 1 lot | Site drainage, oil/water separator, connection to existing stormwater | $12,000 | $20,000 | MJ Civil · Perth Works | |
| Security Fencing | 1 lot | 2.4m palisade/mesh fence with lockable access gate, signage | $10,000 | $18,000 | Perth Works · C&C Contracting | |
| Access Road / Hardstand | 1 lot | Gravel or asphalt access for fuel tanker delivery + crane pad | $15,000 | $25,000 | C&C Contracting · MJ Civil | |
| Civil Subtotal | $137,000 | $228,000 | — | |||
CAPEX 4
Permits, Studies & Professional Services
| Item | Spec / Notes | Low ($) | High ($) | Your Cost ($) | WA Suppliers |
|---|---|---|---|---|---|
| Development Application (DA) | Council planning application, advertising fees | $8,000 | $15,000 | KASA Consulting | |
| DWER Works Approval | Prescribed premises application fee + enviro consultant | $10,000 | $20,000 | KASA · Env Site Services | |
| Noise Assessment | Pre- and post-commissioning noise modelling | $8,000 | $15,000 | Lloyd George Acoustics · EcoAcoustics | |
| DMIRS Dangerous Goods Licence | Application fee + safety consultant | $3,000 | $6,000 | KASA Consulting | |
| Building Permit | Council building permit + surveyor fees | $5,000 | $10,000 | Local council | |
| Aboriginal Heritage Search | AHIS search + heritage consultant | $3,000 | $8,000 | KASA Consulting | |
| Electrical Engineering Design | 11kV SLD, protection study, switchgear spec | $15,000 | $30,000 | Future Power WA · ISAS | |
| Protection Coordination Study | Fault level analysis, relay grading | $8,000 | $15,000 | Future Power WA | |
| Civil / Structural Engineering | Foundation design, geotech, drainage | $10,000 | $18,000 | C&C Contracting | |
| Project Management | Owner's engineer — procurement, construction, commissioning | $25,000 | $50,000 | Future Power WA | |
| Legal — SPV Setup & Lease | Incorporation, SHA, host site lease | $10,000 | $20,000 | HWL Ebsworth · MinterEllison | |
| Insurance — Construction | Construction all-risks, public liability, transit | $8,000 | $15,000 | AON · Marsh | |
| Permits & Professional Subtotal | $113,000 | $222,000 | — | ||
Total
CAPEX Summary
| Category | Low ($) | Mid ($) | High ($) | Your Cost ($) |
|---|---|---|---|---|
| 1. Equipment & Gensets | $1,543,000 | $1,779,000 | $2,014,000 | — |
| 2. Electrical & Protection | $161,000 | $209,000 | $256,000 | — |
| 3. Civil & Site Works | $137,000 | $183,000 | $228,000 | — |
| 4. Permits & Professional | $113,000 | $168,000 | $222,000 | — |
| Base CAPEX | $1,954,000 | $2,339,000 | $2,720,000 | — |
| Contingency (15%) | $293,000 | $351,000 | $408,000 | — |
| All-In CAPEX | $2,247,000 | $2,690,000 | $3,128,000 | — |
Compare with WP connection route. A new WP connection would add $275K–$1.5M+ in
connection costs (enquiry through execution) plus $200K–$400K in GPS modelling and network studies.
The BTM approach eliminates all of this, saving $475K–$1.9M.
Operating
Annual Operating Costs (OPEX)
The plant operates as a standby asset — paid to be available via capacity credits, not to run. Expected dispatch is <50 hours per year (emergency dispatch only). Annual OPEX is therefore dominated by maintenance and fixed costs.
| Item | Basis | Low ($/yr) | High ($/yr) | Your Cost ($) | WA Suppliers |
|---|---|---|---|---|---|
| Preventive Maintenance | Cat dealer CSA — oil, filters, inspections | $25,000 | $40,000 | WesTrac · EPSA | |
| Battery & Coolant | Starter battery (2–3 yrs), coolant flush (3 yrs), amortised | $3,000 | $5,000 | WesTrac | |
| Standby Fuel Consumption | Weekly test runs ≈ 23,400 L/yr | $20,000 | $28,000 | BP · Viva Energy | |
| Insurance — Operational | ISR, public liability, machinery breakdown | $20,000 | $40,000 | AON · Marsh | |
| Site Lease / Host Agreement | Annual licence fee to host site owner | $30,000 | $60,000 | Negotiated | |
| AEMO Market Fees | WEM participant fees, metering | $500 | $1,000 | AEMO | |
| DWER Operating Licence | Annual prescribed premises licence fee | $1,500 | $3,000 | DWER | |
| Accounting & Admin | SPV bookkeeping, audit, ASIC fees, tax | $5,000 | $10,000 | HWL Ebsworth | |
| Remote Monitoring / SCADA | Data plan, cloud hosting, alarm service | $2,000 | $5,000 | ISAS | |
| Total Annual OPEX | $107,000 | $192,000 | — | ||
Emergency dispatch fuel is excluded. If dispatched during a genuine emergency, fuel
costs are ~$1,780/hr at full load (2 units × 494 L/hr × $1.80/L). However, emergency dispatch at
very high spot prices (>$1,000/MWh) would more than cover fuel costs. Dispatch events are
expected ≤5 per year.
Benchmarks
Cost Per MW Analysis
$557K
CAPEX / MW (mid)
$640K
All-In / MW (mid)
$33K
OPEX / MW / yr (mid)
$216K
CC Revenue / MW / yr
Net revenue per MW per year: $216K (CC) − $33K (OPEX) = $183K net / MW /
year. × 4.20 MW = $769K net annual revenue. Payback on $2.69M mid-case
CAPEX = ~3.5 years (conservative). See the Financial Model for sensitivity scenarios.
Comparison — BTM vs New WP Connection
| Cost Component | BTM (This Plan) | New WP Connection | Saving |
|---|---|---|---|
| Equipment & Gensets | $1,779,000 | $1,779,000 | $0 |
| Electrical & Protection | $209,000 | $209,000 | $0 |
| Civil & Site Works | $183,000 | $250,000 | $67,000 |
| WP Connection (Enquiry–Planning) | $0 | $690,000 | $690,000 |
| WP Execution (construction) | $0 | $1,000,000 | $1,000,000 |
| GPS Modelling & Studies | $0 | $300,000 | $300,000 |
| Permits & Professional | $168,000 | $250,000 | $82,000 |
| Total (mid) | $2,339,000 | $4,478,000 | $2,139,000 |