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How many solar panels does it take to power your EV?

Pick a car, how far you drive, and where you live. We'll follow the energy from sunlight to your battery, show every step of the math, and compare the two most common ways to wire a home solar system: a string inverter and Enphase microinverters.

1. Choose your car

2. How far do you drive?

3. Where do you live?

Advanced: prices & assumptions

Prices (for cost & payback)

Solar assumptions

Your car's appetite

YOU DRIVE mi/day× EFFICIENCY kWh/miENERGY NEEDED kWh/day
  1. 1
    Miles per day mi/yr ÷ 365 = mi/day
  2. 2
    Energy per mile kWh/100 mi ÷ 100 = kWh/mi
  3. 3
    Energy per day mi × kWh/mi = kWh/dayEPA efficiency ratings are measured at the wall, so charging losses are already included.

One panel's day: string inverter vs. microinverters

Both systems start with the same panel: a Qcells Q.TRON BLK M-G2+ 430, from America's top-selling residential panel brand. What's different is how its DC power becomes the AC power your charger uses.

🔌 String inverter

SolarEdge Home Wave SE7600H + S440 power optimizers

HIGH-VOLTAGE DC STRINGINVERTERoptimizer
  1. 1
    Panel output (DC) W × sun-hrs ÷ 1000 = kWh
  2. 2
    After system losses × (1 − ) = kWh
  3. 3
    Optimizer (98.6% weighted) × 0.986 = kWh
  4. 4
    Inverter (99% CEC) × 0.99 = kWh AC/day
Panels needed kW DC · ~ sq ft of roof
Approximate installed cost kW × 1,000 × $/W =
Payback vs. grid charging Payback vs. buying gas

⚡ Enphase microinverters

Enphase IQ8HC — one microinverter per panel

IQ8IQ8IQ8IQ8240 V AC TRUNK CABLECOMBINER
  1. 1
    Panel output (DC) W × sun-hrs ÷ 1000 = kWh
  2. 2
    After system losses × (1 − ) = kWh
  3. 3
    Microinverter (97.0% CEC) × 0.970 = kWh AC/day
  4. 4
    Clipping check W panel ÷ 380 VA max = DC/AC
Panels needed kW DC · ~ sq ft of roof
Approximate installed cost kW × 1,000 × $/W =
Payback vs. grid charging Payback vs. buying gas

The bottom line

To cover miles a year in a , you need about panels ( kW) with microinverters, or with a string inverter. That's roughly kWh a year.

What it costs, and what it saves

  1. 1
    Solar the system makes per year panels × kWh/day × 365 = kWh (microinverters)
  2. 2
    Value as electricity kWh × $/kWh = /yrAssumes your utility credits solar you export at the retail rate (net metering). If exports earn less, payback takes longer.
  3. 3
    Gas it replaces mi ÷ mpg × $/gal = /yr
  4. 4
    Simple payback ÷ /yr = vs. gas · ÷ /yr = vs. grid

Prices are before incentives: the 30% federal residential solar tax credit ended December 31, 2025, though some states and utilities still offer rebates. $2.57/W is the national median quote; microinverter systems typically run about $0.25–0.45/W more. A small stand-alone system usually costs more per watt than adding panels to a larger one, so get quotes.

On paper the two are nearly identical: a difference in conversion efficiency. In practice the choice comes down to other things:

String inverter + optimizers

  • Highest rated conversion efficiency (99% inverter, 98.6% optimizer).
  • One inverter on the wall; if it fails, the whole array stops until it's replaced.
  • Inverter warranty is typically shorter than the panels' 25 years.
  • Optimizers handle shading panel-by-panel, like micros.

Enphase microinverters

  • No high-voltage DC on the roof; each panel works independently.
  • A single failure only takes one panel offline.
  • Easy to add panels later, one at a time — handy if you add a second EV.
  • Each micro has an AC limit (380 VA for IQ8HC), so very large panels can clip at peak.

Peak sun hours are an annual average. Your panels make more in summer and less in winter, and most people charge at night, so this assumes net metering or a battery to bank daytime solar for evening charging. For a site-specific estimate, use NREL PVWatts.

Want to know what that electricity is worth? Compare the cost of EV vs. gas for 100 miles →

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