How Many Solar Panels Do You Need to Charge an Electric Vehicle (EV)?

As solar power and electric vehicles (EVs) converge, many eco-conscious homeowners are asking: how many solar panels are needed to charge an electric car? This guide explores the factors affecting solar EV charging and provides real-world calculations to help you plan an efficient, clean-energy home charging setup.

Daily Energy Consumption Example: Hyundai IONIQ 5 LR-AWD

Take the Hyundai IONIQ 5 Long Range AWD as an example. With a daily driving distance of 40km and energy consumption of 0.179 kWh/km, it uses approximately 7.16 kWh per day.

A 400W solar panel in an area with 6 hours of daily sunlight generates about 2.4 kWh/day in ideal conditions. In cloudy conditions, output may drop to 0.6 kWh/day. This means:

• 3 panels required under full sun
• 12 panels under cloudy conditions

Key Factors Affecting Solar EV Charging

1. Electric Vehicle Specifications

Battery size and efficiency vary widely:

• A Fiat 500e (42kWh battery) needs ~25kWh to recharge 60%
• A Mustang Mach-E GT (98.7kWh battery) needs ~59kWh

EVs with higher battery capacities or lower efficiency will require more solar electricity to replenish the same percentage of charge.

2. Daily Driving Habits

Most EV users don’t need to fully recharge every day. Daily mileage matters:

• US average: 60 km/day
• EU average: 12.4 km/day

Shorter commutes = fewer panels needed.

3. Solar Panel Efficiency & Wattage

Solar panels range from 350W–550W. Efficiency and quality affect performance. Higher wattage and better orientation maximize output. Examples:

• 400W panel x 6 hrs = 2.4 kWh/day
• 500W panel x 4.5 hrs = 2.25 kWh/day

4. Sunlight Availability (Peak Hours)

Location determines sunlight intensity.

• California: ~8 hours/day = 3.2 kWh per 400W panel
• London: ~4 hours/day = 1.6 kWh per 400W panel

GHI (Global Horizontal Irradiation) and shading must be considered. Less sun = more panels.

Calculating Your Solar Panel Needs

Step 1: EV Daily Energy Use

Example: Hyundai IONIQ 5

• 40 km/day × 0.18 kWh/km = 7.2 kWh/day

Step 2: Panel Output

• California: 3.2 kWh/day → 7.2 / 3.2 = 2.25 → 3 panels
• London: 1.6 kWh/day → 7.2 / 1.6 = 4.5 → 5 panels

Real-World Panel Requirements by Location & EV

Note: Real-world performance may vary with weather, panel degradation, and orientation.

Should You Add Battery Storage?

Adding home battery storage lets you save solar energy generated during the day for charging at night. It also allows flexibility and can reduce the total panel count needed for daily EV recharging. Storage systems offer backup options for cloudy days and increase energy independence.

Are Solar Panels Worth It for EV Charging?

Yes. Solar EV charging reduces your carbon footprint and can lead to long-term savings. However, to size your system accurately:

• Know your EV’s efficiency
• Track your average daily driving
• Account for your area’s solar exposure
• Match panel wattage and quantity accordingly

In most cases, 3–7 solar panels will cover a 40km daily commute. Install more to ensure coverage on cloudy days or for simultaneous home energy use.