Fleet EV Charging: The Complete UK Infrastructure Guide

Fleet electrification isn't just about vehicles - it's about building an energy ecosystem. Get the charging infrastructure right and your TCO drops by 30%. Get it wrong and EVs cost more than diesel.

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Why Infrastructure Determines Fleet EV Success

Public Charging Dependency

Energy cost: 75p+/kWh at rapid chargers

Cost per mile: 20-25p (more than diesel)

Driver downtime: 30-60 min per charge

Unpredictable availability: Queue risk

TCO advantage: None - often worse than diesel

Depot-First Strategy

Energy cost: 8-10p/kWh (off-peak depot)

Cost per mile: 3-4p

Driver downtime: Zero (overnight charging)

100% availability: Ready every morning

TCO advantage: 70-80% fuel cost reduction

The Infrastructure Imperative

A fleet that relies on public charging will not achieve TCO parity with diesel. Investing in depot infrastructure is the only way to secure the energy costs (3-4p/mile vs 17-20p/mile diesel) that make electrification financially viable. This isn't optional - it's the business case.

5-Year TCO: Electric vs Diesel Van Fleet

Cost ComponentDiesel (ICE)Electric (EV)Notes
Vehicle Purchase£30,000£45,000EV premium ~50%
Plug-in Van Grant£0-£5,000Up to £5,000 for large vans
Fuel/Energy (100k miles)£17,400£4,000Depot charging at 9p/kWh
Maintenance (SMR)£4,500£2,500No oil, filters, reduced brakes
VED (Road Tax)£1,500£500EVs taxable from 2025
ULEZ/CAZ Charges£5,000+£0~£23/day London ULEZ avoided
Infrastructure (amortised)£0£5,000Share of depot charger install
Total 5-Year Cost£58,400£51,600Save £6,800/vehicle

Based on Ford Transit Custom, 20,000 miles/year, diesel at £1.50/L achieving 35mpg. Depot electricity at 9p/kWh off-peak.

How Many Chargers Does Your Fleet Need?

Fleet SizeRatio (EV:Charger)Rationale
Small (<10 vehicles)1:1High redundancy required - single charger failure impacts operations significantly
Medium (10-50)1.5:1Vehicle rotation manageable - software moves vehicles once charged
Large (50+)2:1Sophisticated load management allows asset sharing - significant CAPEX savings
Operational Critical1:1Emergency services, delivery fleets with simultaneous start times - 100% readiness required

7kW AC

Overnight depot charging

25-30 miles/hour • Best for: Predictable routes <100mi/day

22kW AC

Shift-change charging

75-90 miles/hour • Limited by vehicle OBC (often 11kW max)

50kW+ DC

Rapid turnaround

80% in 40-60min • Best for: Multi-shift ops, HGVs

Grid Connection: The Critical Path

Grid connection is frequently the longest lead time in fleet electrification. The "fit and forget" era is over - you must proactively engage your DNO.

Step 1: Assess Your Headroom

Every commercial site has an "Authorized Supply Capacity" (ASC) in kVA. Analyze your half-hourly smart meter data to find your peak demand. The gap between peak and ASC is your headroom for EV charging.

The 30% Rule: If proposed EV load is <30% of total demand and within ASC, a simple DNO notification may suffice. Beyond 30% triggers formal assessment.

Step 2: Submit Early

Apply for the maximum capacity you'll need in 5 years, not just Year 1. Standard G99 approvals take 45-65 working days. Complex applications with reinforcement can take 3-6 months.

Learn about G98 vs G99 requirements →

Step 3: Consider Flexible Connections

Profiled connections allow variable capacity - e.g., 50kVA daytime (when your building needs power), 500kVA overnight (when vehicles charge). This aligns with delivery fleet schedules and avoids costly upgrades.

Reinforcement Costs

If the local network can't supply your needs, you may pay for upgrades. Recent regulatory changes (Significant Code Review) mean DNOs now fund more of this - typically you only pay for "extension assets" (the cable to your site). Costs range from £6,000 for minor works to £100,000+ for new substations.

Smart Charging: Where Software Creates Value

Unmanaged charging - where every vehicle draws maximum power on plug-in - is financially and technically ruinous. Smart charging can let you install 3-4x more chargers on the same grid connection.

Static Load Management

Fixed limit shared across chargers. Example: 100A supply split between 5 chargers. One vehicle gets full current; five vehicles share equally. Simple but inflexible.

Dynamic Load Management

CMS monitors total site load in real-time. As building demand drops overnight, freed capacity goes to EVs. Maximizes existing connection - often 3-4x more chargers than static allows.

Time-of-Use Optimization

Standard business electricity: ~24p/kWh flat rate. Off-peak ToU tariffs: 7-10p/kWh (00:00-05:00).

Smart charging concentrates demand in these cheap windows. For 100 vans each charging 30kWh nightly: off-peak saves £4,200/week vs daytime charging.

Available Grants for Fleet Charging (2025/26)

75%

Depot Charging Scheme

New £30M scheme covers 75% of depot infrastructure costs. For fleets operating electric vans and HGVs.

Cap: Up to £1 million per applicant

£350

Workplace Charging Scheme

Covers 75% of socket costs, capped at £350 each. Up to 40 sockets per applicant (£14,000 max).

Deadline: Ends March 2026

Full WCS guide →
£15k

EV Infrastructure Grant

For SMEs - covers groundworks and cabling, not just chargers. £500 per passive space, £350 per active socket.

Strategic: Wire all bays now, install chargers later

Fleet Electrification in Practice

Royal Mail (Optimise Prime Trial)

World's largest commercial EV trial

Demonstrated profiled connections - by analyzing sorting office loads, they found grid capacity was high overnight. Smart charging limited daytime power and ramped up at night, avoiding costly grid reinforcements.

Key learning: Winter range dropped ~30% due to heating/battery management. Infrastructure sizing must include this buffer.

British Gas (Return-to-Home Fleet)

Distributed charging for service engineers

Thousands of engineers take vans home. Manual processing of home energy receipts was impossible at scale. Solution: direct-to-supplier payment platform (Mina) that pays the driver's energy supplier directly.

Key learning: Digital-first reimbursement models are essential for return-to-home fleets.

Veolia (V2G Trial)

Electric refuse collection vehicles

eRCVs have batteries ~6x larger than passenger cars with predictable downtime. Trial showed two trucks could discharge 110kW - enough to power 110 homes during peak evening hours.

Key learning: Heavy-duty fleets with large batteries can become "virtual power plants" through V2G.

Implementation Roadmap

1

Data Discovery (Months 1-3)

Deploy telematics on ICE fleet. Identify "low-hanging fruit" - vehicles with predictable routes <100 miles/day. Calculate daily kWh requirements, not just mileage.

2

Design & Grid Application (Months 3-9)

Submit G99 for maximum 5-year capacity, not just Year 1. Design site with passive provision (ducting) for 100% of bays - laying extra ducting now is far cheaper than re-excavating later.

3

Procurement & Pilot (Months 9-12)

Procure OCPP-compliant hardware to avoid vendor lock-in. Implement CMS with dynamic load management. Trial payment solutions (Mina/Paua) with a pilot driver group.

4

Scale & Optimize (Year 2+)

Activate smart charging for ToU tariffs. Explore V2G for revenue generation. Transition energy contracts to Corporate PPAs for long-term price hedging.

Frequently Asked Questions

For small fleets (<10 vehicles), plan a 1:1 ratio for redundancy. Medium fleets (10-50) can use 1.5:1 with rotation. Large fleets (50+) often work with 2:1 using smart load management. Strictly operational fleets needing simultaneous readiness (delivery, emergency services) should stick with 1:1.
Depot charging at off-peak rates (8-10p/kWh) costs approximately 3-4p per mile. Standard business electricity runs about 6-7p per mile. Public rapid charging (75p+/kWh) costs 20-25p per mile - often more expensive than diesel. The TCO advantage depends entirely on maximising depot charging.
G99 approval is required for any generation/storage system over 16A per phase. This captures most commercial depot projects involving onsite solar, battery storage, or V2G chargers. Standard "load-only" EV chargers don't require G99, but you will need DNO approval for significant demand increases.
The Depot Charging Scheme covers 75% of costs up to £1 million. The Workplace Charging Scheme offers £350 per socket (up to 40). The EV Infrastructure Grant for Staff and Fleets provides up to £15,000 per building for SMEs, covering passive provision and groundworks.
Options include: profiled connections (higher capacity overnight when needed), flexible connections with Active Network Management (DNO can curtail during emergencies), dynamic load management (smart software distributes power across vehicles), and battery storage for peak shaving.
V2G allows EVs to discharge energy back to the grid, enabling arbitrage (charge cheap, sell high) or frequency response services. It's particularly viable for heavy-duty fleets with large batteries and predictable downtime - Veolia's refuse truck trial showed two trucks could discharge 110kW, enough for 110 homes.

Ready to Electrify Your Fleet?

Get expert advice on depot charging infrastructure, grid connections, and available grants for your fleet electrification project.

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