Electric Vehicle Charging with Solar: Complete Guide for Australian Homes

Planning to buy an electric vehicle? Combining EV charging with solar is a game-changer. This guide shows you how to power your car with sunshine, saving $1,500-$2,500 annually compared to grid charging.

Quick Numbers

Tesla Model 3 Annual Charging:

• Distance: 15,000 km/year (average Australian)
• Energy needed: 2,550 kWh
• Solar required: +2-3kW system capacity
• Annual savings vs grid: $765
• Annual savings vs petrol: $2,100

Charging Cost Comparison:

System Sizing for EV

Additional Solar Capacity Needed

Calculate Your Needs:

Daily Driving:

• 50 km/day = 8.5 kWh
• 75 km/day = 12.8 kWh
• 100 km/day = 17 kWh

Solar Sizing:

• Light use (< 50km/day): +2-3kW
• Average use (50-75km/day): +3-4kW
• Heavy use (> 75km/day): +5-6kW

Example System Sizing:

EV Efficiency by Model

Energy Consumption (kWh per 100km):

Most EVs: 15-18 kWh per 100km

Charging Strategies

Strategy 1: Daytime Solar Charging (Best)

Setup:

• Charge 10am-3pm when solar generating
• Level 2 charger (7kW)
• Home during day or smart scheduling

Pros:

• 100% solar powered
• Minimal grid import
• Best financial return
• Simple setup

Ideal For:

• Work from home
• Flexible schedule
• Second car for home use
• Retirees

Reality Check: Need 20-25 kWh surplus solar for full EV charge

Strategy 2: Battery + Evening Charging

Setup:

• Solar charges battery during day
• EV charges from battery evening
• 13-20 kWh home battery
• Timer-controlled charging

Pros:

• Charge anytime
• Still solar powered
• Backup power benefit
• Works for 9-5 workers

Cons:

• Battery cost ($10-15k after rebates)
• Battery capacity limits
• More complex system

Best For:

• Can't charge during day
• Want backup power anyway
• High electricity rates

Strategy 3: Split Charging

Setup:

• Partial solar charge during day
• Top-up from grid off-peak
• Smart charger scheduling
• Time-of-use tariff

Example:

• Solar charges 12 kWh (11am-3pm)
• Grid charges 8 kWh (11pm-6am @ $0.15/kWh)
• Total cost: $0 + $1.20 = $1.20 per day

Pros:

• Works without battery
• Cheaper than full grid
• Flexible
• Realistic for workers

Best For:

• Standard 9-5 schedule
• Medium solar system
• No battery

Charger Types

Level 1: Standard Outlet (2.4kW)

Specs:

• Regular 10A power point
• 2.4kW charging rate
• 10-12 km range per hour
• Comes with most EVs

Charging Time:

• 40 kWh battery: 16-17 hours
• Overnight: ~100 km range added

Pros:

• No installation cost
• Use existing outlet
• Simple

Cons:

• Very slow
• Not ideal for daily use
• Limits solar charging window

Verdict: Emergency backup only

Level 2: Dedicated EV Charger (7kW)

Specs:

• Hardwired 32A circuit
• 7kW charging rate
• 40-45 km range per hour
• Professional installation

Charging Time:

• 40 kWh battery: 5-6 hours
• Lunch-to-dinner: 120+ km range

Installation Cost: $800-$1,500

Pros:

• Reasonable speed
• Works with solar timing
• Safe and efficient

Cons:

• Installation cost
• Electrician required

Verdict: Recommended for most

Popular Models:

• EVSE Australia ($850 installed)
• JET Charge ($1,100 installed)
• Tesla Wall Connector ($750 + install)
• Zappi (solar-smart, $1,400 installed)

Level 3: Fast Charging (22kW+)

Specs:

• Three-phase power required
• 11-22kW charging rate
• 60-120 km per hour

Installation Cost: $2,000-$4,000

Pros:

• Very fast charging
• Future-proof

Cons:

• Expensive installation
• Requires three-phase
• Exceeds solar capacity

Verdict: Overkill for home use

Smart Charging Features

Solar Tracking

What It Does:

• Monitors solar production
• Adjusts EV charge rate
• Uses only excess solar
• Stops if clouds appear

Chargers With This:

• Zappi (best solar integration)
• Ohme
• Some Tesla features

Benefit: True solar-only charging

Scheduling

What It Does:

• Set charging times
• Coordinate with TOU rates
• Start/stop automatically

Available On: Most Level 2 chargers

Use Cases:

• Charge 10am-3pm workdays
• Off-peak top-ups
• Weekend flexibility

Time-of-Use Tariffs

Solar-Friendly Plans

Optimize for:

• High midday solar export rate
• Low off-peak import rate
• EV-specific discounts

Example Plan (Amber Electric):

• Peak (4-9pm): $0.35-$0.50/kWh
• Shoulder: $0.25-$0.30/kWh
• Off-peak (11pm-6am): $0.12-$0.18/kWh
• Solar export: Wholesale (varies)

Strategy:

• Charge from solar midday (free)
• Backup charge off-peak ($0.15/kWh)
• Avoid peak times

EV-Specific Plans

AGL EV Night Saver:

• Super off-peak: $0.08/kWh (12am-6am)
• Higher rates other times
• Good if can't charge solar

Origin EV Plan:

• Free weekend charging (some periods)
• Discounted rates for EVs
• Solar-friendly

Real-World Examples

Example 1: Brisbane Work-from-Home

Setup:

• 10kW solar system
• Tesla Model 3
• 7kW home charger
• No battery

Usage:

• Home daily: 22 kWh
• EV: 50 km/day = 7.5 kWh
• Total: 29.5 kWh/day

Solar Generation: 35 kWh/day average
Charging: 11am-2pm daily (3 hours = 21kW available)

Result:

• 100% solar charging
• Export excess solar
• Zero EV running costs
• Saving $1,890/year vs petrol

Example 2: Melbourne 9-5 Worker

Setup:

• 8kW solar + 13.5kWh battery
• BYD Atto 3
• 7kW charger
• Charge 6pm-10pm

Usage:

• Home: 25 kWh/day
• EV: 60 km/day = 9.6 kWh
• Total: 34.6 kWh/day

Solar Generation: 28 kWh/day average

Energy Flow:

• Solar direct: 9 kWh
• Battery storage: 13 kWh
• Exported: 6 kWh
• EV from battery: 9.6 kWh
• Home evening from battery: 3.4 kWh
• Grid import: 12.6 kWh

Result:

• 73% solar/battery powered
• EV cost: $0.35/day (vs $3.50 petrol)
• Annual saving: $1,150 vs petrol

Example 3: Sydney Split Charging

Setup:

• 6.6kW solar (existing)
• Hyundai Ioniq 5
• 7kW charger
• No battery

Usage:

• Home: 28 kWh/day
• EV: 80 km/day = 14.4 kWh
• Work 9-5 schedule

Charging Strategy:

• 12 noon-3pm: 7kW × 3 hours = 21 kWh (solar)
• Remaining 3 kWh from grid off-peak

Solar Generation: 25 kWh/day

• Home use direct: 7 kWh
• EV charge: 11 kWh (partial)
• Exported: 7 kWh

Result:

• EV 76% solar powered
• Daily EV cost: $0.45
• Annual saving: $1,480 vs petrol

Financial Analysis

System Cost: Solar + EV Charging

6.6kW Solar System:

• System: $5,000
• 7kW charger: $1,200
• Total: $6,200

8kW Solar + 13.5kWh Battery:

• Solar: $6,500
• Battery: $9,000 (after rebate)
• Charger: $1,200
• Total: $16,700

Payback Calculation

Example: Adding 3kW Solar + Charger

• Cost: $2,500 (solar) + $1,200 (charger) = $3,700
• Petrol savings: $1,890/year
• Electricity offset: $385/year
• Total benefit: $2,275/year
• Payback: 1.6 years

Adding Battery for Evening Charging:

• Additional cost: $9,000
• EV solar usage increase: +$450/year
• Home solar usage increase: +$400/year
• VPP earnings: +$400/year
• Total battery benefit: $1,250/year
• Battery payback: 7.2 years

Is Battery Worth It for EV?

Without Battery

Can Charge Solar:

• Work from home
• Flexible schedule
• Weekend warrior EV
• Second vehicle

Verdict: Battery not essential

Battery Makes Sense If:

1. Can't charge during day
2. Already want backup power
3. High evening usage anyway
4. Premium electricity rates
5. Future-proofing

Reality: Battery enables solar EV charging for 9-5 workers

Common Questions

Q: Will my solar cover an EV?
A: Most likely. 6.6kW system generates enough for EV + typical home. May need 8-10kW for large EV or high driving.

Q: Can I charge from solar at night?
A: Only with battery storage. Battery charges during day, EV uses at night.

Q: Do I need three-phase for EV?
A: No. Single-phase 7kW charging is fine for home use. Three-phase only needed for fast charging.

Q: What if I go on a road trip?
A: Use public charging network. Solar covers daily driving; road trips need fast charging.

Q: Will EV drain my battery backup?
A: Set EV to charge from specific sources. Most systems let you protect battery backup reserve.

EV + Solar Action Plan

Already Have Solar?

1. Check capacity: Do you have excess solar?
2. Calculate EV needs: Daily km × 0.17 = kWh needed
3. Assess timing: Can you charge 10am-3pm?
4. Consider battery: If can't charge daytime
5. Install charger: Book electrician

Getting Solar + EV Together?

1. Size appropriately: Home + EV needs
2. Future-proof: Add 20% capacity
3. Consider battery: For evening charging
4. Plan layout: Charger location
5. VPP: Join if available

Buying EV Soon?

1. Get solar now: Start saving immediately
2. Oversize slightly: Add 2-3kW for EV
3. Install charger: Ready for EV arrival
4. Plan charging: Decide strategy
5. Switch tariff: To EV-friendly plan

The Bottom Line

Charging an EV with solar is highly practical and economical. Adding 2-3kW solar capacity costs $2,500 but saves $1,800+ annually compared to petrol.

Key Takeaways:

• EV adds 8-15 kWh daily consumption
• Need +2-5kW solar capacity
• Daytime charging uses 100% solar
• Battery enables evening charging
• Saves $1,500-$2,500 vs petrol annually
• Payback: 1.5-3 years typical

Best Strategy:

• Work from home: Solar only, charge 10am-3pm
• Work away: Solar + battery for evening
• Flexible: Split solar/off-peak charging

Ready to calculate your solar needs with an EV? Use our Solar Calculator and add EV charging to your usage profile.