Can Solar Panels Lower Your EV Charging Cost?
Discover how solar panels can dramatically reduce your EV charging costs, provide energy independence, and create a truly sustainable transportation solution.
Last updated: October 2025
Solar saves the most when your EV charging directly uses your own solar (self-consumption) during cheap/export-poor hours. Savings depend on your import rate, any export credit (NEM/net billing), your solar cost per kWh, and charging efficiency. Schedule charging for sunny mid-day (or store solar in a home battery, then charge off-peak).
- •Self-consumption: Every kWh you charge from your array avoids buying at the retail import rate.
- •Export credit (NEM/net billing): If you export then buy back later, your value is your utility's export rate (often much lower than retail under NEM 3.0-style "net billing").
- •Battery: Lets you time-shift solar to night; subtract round-trip losses (~8–15%) when estimating cost.
- •TOU: Off-peak imports are cheaper; many regions have peak 4–9 p.m., so mid-day solar EV charging can outperform exporting.
- •Cost per mile on solar (self-consumed) ≈ (Solar cost $/kWh) ÷ (mi/kWh × 0.90).
- •Extra savings from charging mid-day (no battery) ≈ Import rate − Export credit (¢/kWh).
- •With a battery: Effective stored-solar cost ≈ (Solar cost ÷ battery round-trip efficiency).
- •Grid vs solar cost-per-mile: If your solar cost is ~$0.10/kWh and your car averages 3.5 mi/kWh, cost ≈ $0.10 ÷ (3.5×0.90) ≈ 3.2¢/mi. At $0.18/kWh grid, ≈ 5.7¢/mi.
- •Net billing (export-poor): If import is ~$0.31/kWh and export averages ~$0.08/kWh, charging 200 kWh/month directly from solar vs exporting then buying back saves ≈ (31−8)×200 = ~$46/month.
- •Battery time-shift: If solar is $0.10/kWh and battery round-trip is 0.88, stored-solar ≈ 11.4¢/kWh. Still below many peak retail rates.
Monthly kWh for your EV ≈ (monthly miles ÷ mi/kWh) ÷ 0.90. Add that energy to your solar target. (Panel count depends on your sun hours and installer's design.)
- •U.S. Residential Clean Energy Credit: 30% for eligible solar installed 2022–2032 (phases down after), and standalone batteries ≥3 kWh qualify.
- •California NEM 3.0 / Net Billing: Export credits are based on avoided cost and are much lower than retail; self-consumption or storage improves EV-charging value.
(Always confirm active rules with your utility before purchasing.)
Use scheduled charging in your vehicle/app to prioritize sunny mid-day (if no battery) or off-peak nights (with battery), and set a departure-ready time.
| Scenario | Monthly EV Charging | Grid Cost | Solar Cost | Annual Savings |
|---|---|---|---|---|
| Compact EV (1,000 mi/mo) | 250 kWh | $37.50 | $0-5.00 | $390-450 |
| Mid-size EV (1,000 mi/mo) | 350 kWh | $52.50 | $0-7.00 | $546-630 |
| Large EV/SUV (1,000 mi/mo) | 450 kWh | $67.50 | $0-9.00 | $702-810 |
| Electric Truck (1,000 mi/mo) | 600 kWh | $90.00 | $0-12.00 | $936-1,080 |
Compact EV (1,000 mi/mo)
Mid-size EV (1,000 mi/mo)
Large EV/SUV (1,000 mi/mo)
Electric Truck (1,000 mi/mo)
*Based on $0.15/kWh grid rate and $0.02-0.04/kWh solar cost (including system amortization)
1. Solar Generation
Solar panels generate electricity during daylight hours
2. Energy Storage/Grid
Excess energy stored in batteries or sent to grid via net metering
3. EV Charging
EV charges using solar power directly or stored energy
Three Solar + EV Charging Scenarios:
Recommended Solar System Sizes
Home Only (No EV)
- • Small home: 4-6 kW system
- • Medium home: 6-8 kW system
- • Large home: 8-12 kW system
Home + EV Charging
- • Add 3-4 kW for compact EV
- • Add 4-6 kW for mid-size EV
- • Add 6-8 kW for large EV/truck
| EV Type | Monthly kWh | Additional Solar kW | Annual Generation | System Cost |
|---|---|---|---|---|
| Compact EV | 250 kWh | 2.5-3 kW | 3,000-3,600 kWh | $5,000-7,500 |
| Mid-size EV | 350 kWh | 3.5-4 kW | 4,200-4,800 kWh | $7,000-10,000 |
| Large EV/SUV | 450 kWh | 4.5-5 kW | 5,400-6,000 kWh | $9,000-12,500 |
| Electric Truck | 600 kWh | 6-7 kW | 7,200-8,400 kWh | $12,000-17,500 |
Compact EV
Mid-size EV
Large EV/SUV
Electric Truck
*Costs shown are before federal tax credits (30%) and local incentives. Actual generation varies by location and weather.
Example: Tesla Model Y + 4 kW Solar Addition
Investment
• Solar system cost: $8,000
• Federal tax credit (30%): -$2,400
• Net investment: $5,600
Annual Savings
• EV charging savings: $630
• Additional home savings: $200
• Total annual savings: $830
Payback Period: 6.7 years
25-year total savings: $15,150 (after system cost)
Best Case Scenario
High electricity rates + good solar conditions
4-6 year payback
Average Scenario
Moderate rates + average solar
6-8 year payback
Challenging Scenario
Low rates + poor solar conditions
8-12 year payback
Assess Your Situation
Evaluate your roof space, sun exposure, current electricity usage, and EV charging needs.
Get Multiple Quotes
Compare proposals from 3-5 certified solar installers. Include EV charging requirements in your discussions.
Understand Net Metering
Learn your utility's net metering policies and how they affect your solar + EV economics.
Consider Smart Charging
Install smart EV chargers that can prioritize solar power and optimize charging times.
Plan for the Future
Size your system for potential future EVs or increased electricity usage.
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