5 units × 120kW = 1.3 Years to Recover the Cost

I. Transformer Configuration

Capacity Calculation

• Power per charging pile: 120kW
• Total power demand: 5 sets x 120kW = 600kW.
• Actual load consideration: Charging piles usually do not operate at full load at the same time, so a simultaneous usage coefficient (0.7-0.8) should be introduced.
• Minimum demand: 600kW x 0.7 = 420kW
• Recommended capacity: Considering the power factor (about 0.9) and margin, choose 630kVA box-type transformer.

Technical Requirement

• Voltage class: 380V three-phase four-wire system
• Cooling method: natural cooling or forced air cooling.
• Protection grade: IP54 or above (dustproof and waterproof)

II. Cost Estimate

Equipment and installation costs

• Charging piles: 5 x CNY 35,000/set ≈ CNY 175,000.
• Transformer: 630kVA box transformer (including installation) ≈ CNY 120,000-180,000.
• Supporting facilities: cables, power distribution cabinets, monitoring systems, etc. ≈ CNY 60,000-100,000.
• Site Costs: If you need to rent five parking spaces, annual rent is about CNY 15,000-30,000 (depending on the location).

Platform Access Cost

• Initial investment: platform interface fee and management system construction ≈ CNY 30,000-50,000.
• Annual operation and maintenance fee: software service fee+manual management ≈ CNY 80,000-120,000 /year.

Total initial investment

Combined equipment, installation and platform access costs:

CNY 175,000 (charging pile)+ CNY 150,000 (transformer)+ CNY 80,000 (supporting)+ CNY 50,000 (platform) ≈ CNY 455,000.

(excluding potential expenses such as site rent and power capacity increase fees).

III. Profit Analysis

Income model

Assumptions:

• Daily usage time per charging pile: 6-8 hours (calculated at the conservative value of 6 hours)
• Charging efficiency: 90%
• Service fee: CNY 0.3-0.5/kWh (taking CNY 0.4 /kWh as an example)
• Electricity cost: CNY 0.7-0.8/kWh (total price paid by users is about CNY 1.1-1.3 /kWh).

Annual charge:

5 sets × 120kW × 6h × 365 days× 0.9 ≈ 1,182,600kwh.

Annual income:

• Service fee income: 1,182,600 kWh × CNY 0.4≈ CNY 473,000.
• Electricity cost: 1,182,600 kWh × CNY 0.8≈ CNY 946,000 (to be paid to the power grid).

Operating costs

Fixed cost: venue rent CNY 30,000 + operation and maintenance fees CNY 100,000≈ CNY 130,000 /year.

Net profit

If only service fees are charged, and the electricity fee (CNY 946,000) is borne by the user, so the net profit is:

CNY 473,000 yuan (service fee) - CNY 130,000 yuan (fixed cost) ≈ CNY 343,000 /year.

IV. Investment Recovery Period

Optimistic model (usage rate 80%):

Initial investment CNY 455,000 ➗ annual net profit CNY 343,000 ≈ 1.3 years.

Conservative model (usage rate 50%):

Annual net profit CNY 172,000 → recovery period is about 2.6 years.

V. Risks and Optimization Suggestions

Key risks

• Underusage (below 50% may lead to losses)
• Adjustment of electricity price policy (such as peak-valley electricity price difference)
• Approval period and costs of power capacity expansion (additional costs may be required in some regions)

Optimization directions

• Site selection in high-traffic areas (e.g., commercial districts, highway service areas).
• Time-of-use pricing strategy (premium pricing during peak hours)
• Apply for government subsidies (some cities have subsidies for the construction of charging piles)

VI. Summary

• Transformer demand: 630kVA box-type transformer (about CNY 150,000)
• Total investment: about CNY 455,000 (excluding site rent)
• Annual profit: CNY 343,000 (80% utilization rate)
• Recovery period: 1.3-2.5 years (actual period depends on local policies and operational efficiency)