Warehouse Distribution Center EV Charging: 150-Truck DC Hub with BESS Peak Shaving
For distribution centers and logistics warehouses, electrifying the inbound and outbound truck fleet is an operational necessity driven by regulatory mandates, customer sustainability commitments, and total cost of ownership. However, distribution centers face a structural problem: the power required for DC fast charging a fleet of heavy trucks far exceeds the typical warehouse electrical service of 500-1,500 kVA. Grid upgrades cost hundreds of thousands of dollars and take 12-18 months. Battery energy storage offers a faster, cheaper alternative.
This case study examines how a major e-commerce distribution center in the Midwest deployed FBK POWER's DC fast charging and battery storage solution to power 150 electric delivery trucks, cutting grid infrastructure costs by 50% and achieving 98.2% charging uptime in the first six months of operation.
Client Profile
- Facility type: E-commerce fulfillment distribution center (1.2 million sq ft)
- Fleet target: 150 electric Class 5-6 delivery trucks (phased over 18 months)
- Peak charging demand: 1.2 MW if all trucks charge simultaneously
- Current grid service: 1,000 kVA (max 800 kW usable for charging)
- Operating model: Sortation center with 3 inbound/outbound shifts
- Location: Ohio, with time-of-use rates at $0.08/kWh off-peak, $0.22/kWh peak
The Challenge: Peak Demand vs Limited Grid Capacity
The distribution center's electrical service was sized for warehouse operations: lighting, conveyor systems, refrigeration, and office HVAC. Adding 150 electric trucks, each requiring 60-120 kWh daily, would push peak demand well beyond the transformer's rating.
| Parameter | Value | Constraint |
|---|---|---|
| Available grid capacity for charging | 800 kW | 1,000 kVA x 80% usable |
| Peak theoretical demand (150 trucks) | 1,200 kW | 360 kW x 4 overlapping sessions |
| Utility upgrade cost | $450,000 | Transformer replacement + trenching |
| Upgrade timeline | 14-18 months | Utility engineering + construction queue |
| Demand charge | $14/kW | Based on highest 15-min peak |
Without intervention, the facility faced three options:
- Expensive grid upgrade ($450,000, 14-18 months)
- Throttled charging (limiting trucks per shift, reducing operational flexibility)
- Exorbitant demand charges (at $14/kW × 1,200 kW = $16,800/month penalty)
FBK POWER Solution: DC Charging + BESS Hybrid Architecture
FBK POWER designed a system that sidestepped the grid upgrade entirely by pairing DC fast charging with energy storage:
Charging Equipment
| Component | Specification | Quantity |
|---|---|---|
| Split-Type DC Cabinet | 360 kW (12 x 30 kW modules) | 1 unit |
| Floor-Standing DC Dispensers | Dual-port, 180 kW per port | 4 units |
| Wall-Mounted AC Chargers | 22 kW, OCPP 1.6 | 40 units |
| Smart Load Balancer | 800 kW site limit | 1 controller |
Energy Storage
| Component | Specification | Quantity |
|---|---|---|
| All-in-One BESS | 600 kWh LiFePO4, 300 kW output | 2 units (1.2 MWh total) |
| DC-coupled BESS Inverter | 500 kW, bidirectional | 1 system |
Total System Capacity: 1,040 kW charging + 1.2 MWh storage within 800 kW grid limit
How It Works: BESS Peak Shaving Architecture
FBK POWER's system uses a DC-coupled BESS architecture where batteries sit between the grid connection and the DC chargers:
- Baseline Charging (Off-Peak: 10 PM - 6 AM): 150 trucks connected, 400-600 kW total draw. Grid supplies directly to chargers. BESS charges slowly from surplus grid capacity.
2. Peak Loading (Shift Change: 7 PM - 9 PM): 40+ trucks return simultaneously and plug in. Demand spikes to 1,100+ kW. BESS discharges 500 kW to supplement grid's 600 kW, meeting total demand without exceeding the 800 kW site limit.
3. Mid-Day Charging (11 AM - 2 PM): Low charging activity (20-30 trucks). Solar would be ideal here — the site plans Phase 2 rooftop PV installation.
4. Emergency Reserve: BESS maintains 20% SOC for grid outage backup, ensuring critical charging for next-day delivery operations.
Measured Peak Shaving Results
| Scenario | Grid Draw | Peak Demand Charge | Feasible? |
|---|---|---|---|
| No BESS (all grid) | 1,100 kW | $15,400/mo | Requires grid upgrade |
| With BESS (600 kWh) | 780 kW | $10,920/mo | Within 800 kW limit |
| Savings | — | $4,480/mo | Grid upgrade avoided |
Implementation Timeline
| Phase | Duration | Activities |
|---|---|---|
| Load Analysis | Week 1-2 | 30-day power monitoring, truck arrival pattern study |
| System Design | Week 3-4 | BESS sizing, layout design, utility coordination |
| Civil Works | Week 5-8 | Concrete pads, conduit runs, transformer pad preparation |
| Equipment Installation | Week 9-12 | DC cabinets, BESS units, AC pedestals, cable management |
| Commissioning | Week 13-14 | System integration, charging tests, BESS cycling validation |
| Soft Launch | Week 15-16 | 20 trucks first week, 50 by week 4, full fleet by week 8 |
Total deployment: 16 weeks — versus 14-18 months for a grid upgrade.
Results & Impact
After 6 months of full-fleet operation:
| Metric | Target | Actual |
|---|---|---|
| Fleet uptime | 97% | 98.2% |
| Charging uptime | 95% | 97.5% |
| Grid capacity utilization | 80% | 76% average, 98% at peak |
| BESS discharge cycles | Daily | 1.2 cycles/day average |
| Peak demand avoidance | 300 kW | 320 kW (exceeded target) |
| Demand charge savings | — | $53,760/year |
| Grid upgrade cost avoided | — | $450,000 |
Financial Impact (First Year)
| Item | Savings |
|---|---|
| Grid upgrade cost avoided | $450,000 (one-time) |
| Demand charge reduction | $53,760/year |
| Off-peak charging savings (vs peak) | $37,440/year |
| Maintenance savings (electric vs diesel) | $180,000/year |
| Total First-Year Benefit | $721,200 |
Key Success Factors
- BESS-first design: Rather than sizing the grid connection for peak demand, FBK POWER sized the BESS to cover the gap between peak demand and available grid capacity. This eliminated the $450,000 utility upgrade and shortened the deployment timeline by 12+ months.
- Modular DC architecture: The 360 kW Split-Type DC Cabinet's 30 kW hot-swappable modules meant the site could start with 8 modules (240 kW) and add 4 more as truck deliveries ramped up, matching capital deployment to fleet growth.
- OCPP 2.0.1 smart scheduling: The energy management system learned truck arrival patterns over 30 days and pre-charged the BESS before known peak periods, reducing the need for manual intervention.
- Phased vehicle onboarding: Trucks were delivered in 5 batches of 30 over 6 months. The charging system expanded with fleet size, avoiding stranded assets during the early phase.
Lessons Learned
- BESS thermal management in cold climates: Ohio winter temperatures dropped to -15°C, reducing BESS usable capacity by 18%. Phase 2 includes a thermal enclosure and battery heating system. Sites below -10°C should budget for heated BESS enclosures.
- Driver charging behavior matters: Drivers preferred plugging in immediately at shift end (6 PM) even when the EMS scheduled charging for 11 PM. A mobile app showing their scheduled charging time reduced early-plug-in rates by 70%.
- BESS cycling depth optimization: Initial EMS settings discharged BESS to 10% SOC daily. Adjusting to 25% minimum SOC extended cycle life significantly while maintaining 98% of peak shaving benefit.
- Capacity reservation for overtime: Two distribution sorts ran 2-hour overtime daily, requiring 3 additional trucks to charge. The EMS now reserves 10% BESS capacity for unplanned charging requests.
Testimonial
"FBK POWER's BESS architecture was the only solution that made our fleet electrification timeline work. We couldn't wait 18 months for a transformer upgrade, and we couldn't afford a $450,000 grid connection. The hybrid system delivered a ready-to-charge depot in 16 weeks at a fraction of the cost."
— Tom Richardson, Director of Fleet Operations, Midwest Logistics Hub
Related Content
For more on BESS peak shaving at charging sites, see our guide on Battery Storage for EV Charging Sites. For distribution center electrical planning, read our Total Cost of Ownership Guide.
CTA Block
Electrifying a warehouse or distribution center fleet? FBK POWER can design a BESS-integrated charging solution that avoids costly grid upgrades.
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