How Much Electricity Does an EV Need? (By Model & Miles)
The amount of solar you need depends on: (1) Your EV's efficiency (kWh per 100 miles), and (2) Your annual mileage.
| EV Model | Efficiency (kWh/100 mi) | Annual Use (10,000 mi) | Annual Use (15,000 mi) |
|---|---|---|---|
| Tesla Model 3 (RWD) | 26 kWh/100 mi | 2,600 kWh | 3,900 kWh |
| Tesla Model Y (RWD) | 28 kWh/100 mi | 2,800 kWh | 4,200 kWh |
| Chevy Bolt EV | 29 kWh/100 mi | 2,900 kWh | 4,350 kWh |
| Ford Mustang Mach-E | 34 kWh/100 mi | 3,400 kWh | 5,100 kWh |
| Rivian R1T (pickup) | 49 kWh/100 mi | 4,900 kWh | 7,350 kWh |
| Average EV (2026) | ~32 kWh/100 mi | 3,200 kWh | 4,800 kWh |
How Many Solar Panels Do You Need for EV Charging?
To generate the extra electricity for your EV, you need to add 2โ5 kW of solar capacity to your system. Here's the math:
| Annual EV Electricity Need | Extra Solar Capacity Needed | Additional Panels (400W each) | Roof Space Needed |
|---|---|---|---|
| 2,500 kWh/year (~7,000 mi) | ~1.8 kW | 5 panels | 90 sq ft |
| 3,500 kWh/year (~10,000 mi) | ~2.5 kW | 6โ7 panels | 110โ130 sq ft |
| 5,000 kWh/year (~14,000 mi) | ~3.6 kW | 9โ10 panels | 160โ180 sq ft |
| 7,500 kWh/year (~20,000 mi, 2 EVs) | ~5.4 kW | 13โ14 panels | 230โ250 sq ft |
Important: The "extra solar capacity" assumes you size your entire solar system (home + EV) together. If you already have solar, you may need to expand your system or add a "micro-system" dedicated to EV charging.
Cost of Adding Solar for EV Charging (2026 Prices)
| Extra Solar Capacity | Installed Cost (Before ITC) | After 30% ITC | Annual Electricity Savings* |
|---|---|---|---|
| 2.0 kW (5 panels) | $6,000โ$7,000 | $4,200โ$4,900 | $500โ$800 |
| 3.0 kW (7โ8 panels) | $9,000โ$10,500 | $6,300โ$7,350 | $750โ$1,200 |
| 5.0 kW (12โ13 panels) | $15,000โ$17,500 | $10,500โ$12,250 | $1,200โ$2,000 |
*Based on $0.20/kWh electricity rate. If your rate is higher (CA: $0.29/kWh), savings are higher.
Smart EV Charging + Solar: How to Maximize Savings
To get the most from solar + EV, you need a smart charging setup that charges your EV during peak solar production hours (10 AM โ 3 PM).
1. Time-of-Use (TOU) Charging
Many utilities offer EV-specific TOU rates that give you cheap electricity at night (when solar isn't producing) but charge more during peak hours. With solar + battery, you can:
- Charge your EV from solar during the day (free!)
- Or charge from your battery at night (using stored solar)
2. Smart Charging Stations (Solar Integration)
Some EV chargers can integrate with your solar system's monitoring API to automatically charge when solar production exceeds home use. Popular options:
- Tesla Wall Connector + Powerwall: Automatically charges from solar when there's excess production.
- Emporia EV Charger: Integrates with Emporia Vue energy monitor to charge from excess solar.
- ChargePoint Home Flex: Can be scheduled to charge during peak solar hours.
3. Bi-Directional Charging (V2H / V2G) โ Emerging in 2026
Vehicle-to-Home (V2H) and Vehicle-to-Grid (V2G) allow your EV to power your home during outages or send electricity back to the grid. This effectively turns your EV into a giant battery (60โ100 kWh!).
Available in 2026: Ford F-150 Lightning (with Ford Charge Station Pro), Tesla (with Powerwall + bi-directional inverter), and some Nissan Leaf models. More models are coming in 2027โ2028.
Is Solar + EV Worth It? (Financial Analysis)
| Scenario | Extra Solar Cost (After ITC) | Annual Fuel Savings* | Payback Period |
|---|---|---|---|
| Drive 10,000 mi/year (average EV) | $6,500 (3 kW extra) | $900โ$1,200 | 5โ7 years |
| Drive 15,000 mi/year (high-mileage EV) | $9,000 (4 kW extra) | $1,300โ$1,800 | 5โ7 years |
| 2 EVs, 25,000 mi/year combined | $15,000 (6 kW extra) | $2,200โ$3,000 | 5โ7 years |
*Compared to gasoline at $3.50/gallon for a 25 MPG car. If gas prices rise to $5.00/gallon, payback is 3โ5 years.
Frequently Asked Questions
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่ฎก็ฎๆ็ๅคช้ณ่ฝ่็ โโ Frequently Asked Questions
For a typical EV driven 12,000 miles/year, you need 6โ8 additional solar panels (2.5โ3.0 kW). This generates ~3,200 kWh/year, enough to cover the EV's electricity need.
Yes, if you drive 10,000+ miles per year. The payback period for the extra panels is 5โ7 years. After that, you're essentially driving on free sunlight.
Yes! If you have a solar battery (like Tesla Powerwall), you can charge your EV from the battery at night. This maximizes your solar self-consumption.
V2H allows your EV to power your home during outages (or peak hours). Your EV battery (60โ100 kWh) becomes a giant home battery. Available on Ford F-150 Lightning, Tesla (with Powerwall), and some Nissan Leaf models.
Adding 3 kW of solar (for 10,000 mi/year EV use) costs ~$6,500 after the 30% ITC. A Level 2 EV charger adds $500โ$2,000 (depending on electrical upgrades needed).
Only with a special off-grid setup (solar + battery + EV charger). Most grid-tied solar homes charge their EV from the grid (using solar exports as credits). True off-grid EV charging requires 10+ kW of solar and 20+ kWh of battery.