Should I Get Solar Before or After Buying an Electric Vehicle?
The short answer: Get solar first, or at the same time as your EV. Installing solar before (or alongside) your electric vehicle purchase maximizes savings and ensures your system is sized correctly. Waiting until after you buy an EV means months of higher electric bills and potentially needing to expand your solar system later—which costs more than doing it right the first time.
Quick Summary: An EV adds $100-200/month to your California electricity bill. Install solar BEFORE your EV arrives, sized for the combined usage. This approach saves $5,000-15,000 compared to waiting.
How Much Electricity Does an EV Actually Use?
Most California homeowners underestimate EV charging costs:
Real-World EV Electricity Usage:
| Driving Pattern | Miles/Year | kWh Needed | Monthly Cost (SCE 42¢) | Monthly Cost (SDG&E 55¢) |
|---|---|---|---|---|
| Light commuter | 8,000 | 2,400/year | $84 | $110 |
| Average driver | 12,000 | 3,600/year | $126 | $165 |
| Heavy driver | 18,000 | 5,400/year | $189 | $248 |
| Two EVs (avg) | 24,000 | 7,200/year | $252 | $330 |
The bottom line: Your EV adds $100-250/month to your electric bill, depending on how much you drive and which utility you have.
Comparison: Gas vs. EV Costs
| Vehicle | Annual Fuel/Electricity | Monthly Cost |
|---|---|---|
| Gas car (12,000 mi, 28 MPG, $4.50/gal) | $1,929 | $161 |
| EV on SCE (12,000 mi) | $1,512 | $126 |
| EV on SDG&E (12,000 mi) | $1,980 | $165 |
| EV on solar | ~$180 (minor grid use) | ~$15 |
Notice: In SDG&E territory, an EV can cost MORE than gas if you're charging at peak rates without solar. Solar makes EVs actually affordable.
Real Stories: The Cost of Getting the Order Wrong
The Martinez Family — Temecula, CA (SDG&E)
"We bought our Tesla Model Y in March, super excited about saving on gas. Then our first SDG&E bill arrived: $487. Our old electric bill was $290. We'd 'saved' on gas but were paying $200/month more in electricity. We scrambled to get solar installed—took 3 months. Those 3 months cost us $600 in extra electric bills. Should have gone solar first."
Carlos & Elena V. — Riverside, CA (SCE)
"We did it right. Knew we wanted an EV, got solar quotes first. Our installer sized the system for our current usage plus the future EV. We got the Rivian 6 months later. Our solar payment is $165. Our total energy cost—home AND car—is $180/month. Friends with EVs but no solar pay $350+ just for electricity."
Jennifer K. — Corona, CA (SCE)
"We got solar in 2022, sized for our bill at the time. Bought an EV in 2024. Now we're having to add 6 more panels because we didn't plan ahead. That expansion is costing $8,000. If we'd just added them initially, it would have been $4,000 more. Expensive lesson."
The Case for Solar BEFORE Your EV
1. You'll Size Your System Correctly
When you go solar, your system is designed based on your current electricity usage. If you install solar with a $200/month bill, you get a system that covers $200/month of usage.
Then you buy an EV. Suddenly you need another 3,500 kWh per year. Your solar system doesn't cover it. You're back to paying the utility for the difference—at those brutal California rates.
The math:
| Scenario | Solar System | EV Added Usage | Result |
|---|---|---|---|
| Solar first (not sized for EV) | Covers 8,000 kWh | +3,500 kWh | 3,500 kWh from grid = $1,470/year |
| Solar sized for EV | Covers 11,500 kWh | +3,500 kWh | $0 from grid |
| Annual difference | $1,470 |
2. Expanding Later Costs More
Adding panels to an existing system isn't as simple as "just adding a few more panels." It often requires:
- New permit application and fees ($500-1,500)
- Potential inverter upgrade ($1,500-3,000)
- New structural engineering ($300-500)
- Separate installation labor ($1,000-2,000)
- Additional inspection
Cost comparison:
| Timing | Cost for 3 kW of Additional Capacity |
|---|---|
| Added during initial install | $9,000 |
| Added 1-2 years later | $12,000-14,000 |
| Extra cost for waiting | $3,000-5,000 |
3. You Lock In Savings Immediately
Every month between your EV purchase and solar installation, you're paying peak California rates for your car charging.
| Wait Time | Added Electric Cost | Lost Solar Savings |
|---|---|---|
| 1 month | $150 | $150 |
| 3 months | $450 | $450 |
| 6 months | $900 | $900 |
| 12 months | $1,800 | $1,800 |
Solar first = savings first.
4. You Can Charge During Peak Solar Production
Solar panels produce the most electricity during the hottest, sunniest hours—often when your EV sits in the driveway or garage.
Optimal charging with solar:
- 9 AM - 4 PM: Plug in your EV, charge directly from solar
- 4 PM - 9 PM: If needed, use battery-stored solar
- Result: Your car literally runs on sunshine
Without solar:
- Charge overnight (off-peak, but still 35-40¢/kWh)
- Or charge when you get home (peak rates, 55-65¢/kWh)
- Result: Monthly bills that rival gas costs
The Case for Solar AT THE SAME TIME as Your EV
If you're planning an EV purchase in the next 6-12 months, the smartest move is often to install solar now, sized for your post-EV usage.
How This Works:
Step 1: Calculate current usage Check your utility bill: Let's say 8,000 kWh/year
Step 2: Estimate EV usage Average driver: ~3,500 kWh/year
Step 3: Size solar for combined usage 8,000 + 3,500 = 11,500 kWh/year
Step 4: Install now Your system will slightly overproduce for a few months (exports go to grid at NEM 3.0 rates). Once EV arrives, production matches usage perfectly.
NEM 3.0 Consideration:
Under NEM 3.0, excess solar sent to the grid earns reduced credits. But if you're "oversizing" temporarily with a planned EV purchase, you're not really oversizing—you're future-proofing.
Pro tip: Add a battery. Store excess production now, use for evening home needs. When EV arrives, you have the infrastructure ready for overnight EV charging from stored solar.
What If I Already Have an EV?
If you bought your EV first and now you're seeing those electric bills... it's not too late.
Your Options:
Option A: Go solar now, sized for current (EV-inclusive) usage
- Your system covers everything
- Immediate savings
- No future expansion needed
Option B: Go solar now with battery for TOU optimization
- Store cheap/solar power during day
- Charge EV from battery at night
- Maximize savings under time-of-use rates
Real example — Michael T., San Bernardino, CA:
"I bought my Tesla before solar. My SCE bill went from $180 to $340. Installed an 11 kW system with a Powerwall. Now my total monthly energy cost is $175—including driving 15,000 miles a year. I'm spending less than my old electric bill BEFORE the EV."
System Sizing for EV Owners
Here's a quick guide to sizing your solar system with an EV:
Without EV (Baseline):
| Monthly Electric Bill | Approximate System Size |
|---|---|
| $150/month | 5-6 kW |
| $250/month | 7-8 kW |
| $350/month | 9-11 kW |
| $450/month | 12-14 kW |
Add for EV:
| Driving Amount | Added System Capacity |
|---|---|
| Light (8,000 miles/year) | +2.0 kW |
| Average (12,000 miles/year) | +2.5-3.0 kW |
| Heavy (18,000 miles/year) | +3.5-4.0 kW |
| Two EVs | +5.0-6.0 kW |
Combined Example:
| Current bill | $250/month → 7 kW baseline |
|---|---|
| Adding one EV (average driver) | +3 kW |
| Total system size | 10 kW |
The Battery Factor for EV Owners
Batteries become especially valuable when you have an EV:
Why Batteries + EV + Solar Work Together:
Morning (6 AM - 9 AM):
- Solar starts producing
- Power your home
- Begin charging battery
Daytime (9 AM - 4 PM):
- Peak solar production
- If EV is home, charge directly from solar
- Excess fills battery
Evening Peak (4 PM - 9 PM):
- Solar winding down
- Battery powers home
- Avoid 55-65¢/kWh peak rates
Overnight (9 PM - 6 AM):
- Charge EV from battery (if capacity remains)
- Or charge from grid during super off-peak (cheaper)
Without a Battery:
- Daytime solar excess goes to grid (low NEM 3.0 credits)
- Evening home use pulls from grid (expensive peak rates)
- EV charging overnight at off-peak (still 35-40¢/kWh)
- You're buying back your own production at a markup
Battery Sizing for EV Owners:
| Situation | Recommended Battery |
|---|---|
| Home only, no EV | 10-13 kWh (1 Powerwall) |
| Home + 1 EV | 13-20 kWh (1-2 Powerwalls) |
| Home + 2 EVs | 20-27 kWh (2 Powerwalls) |
| Home + EV + whole-home backup | 27-40 kWh (2-3 Powerwalls) |
Level 2 Charging: Essential for Solar + EV
If you're going solar with an EV, you'll want Level 2 (240V) charging:
Charging Speed Comparison:
| Charger Type | Speed | Solar Compatibility |
|---|---|---|
| Level 1 (120V outlet) | 3-5 miles/hour | Poor—too slow to use daytime solar |
| Level 2 (240V, 32A) | 20-25 miles/hour | Good—can charge during solar hours |
| Level 2 (240V, 48A) | 30-35 miles/hour | Excellent—maximizes solar charging |
Why Level 2 matters for solar: A Level 1 charger adds 30-40 miles overnight. But if you want to charge during daytime solar production, you need faster charging. Level 2 can add 150+ miles during a sunny afternoon.
Installation Note:
Many solar installers can add a Level 2 EV charger circuit during the solar installation, often saving money compared to a separate electrician visit later.
Key Takeaways
| Strategy | Result |
|---|---|
| Solar BEFORE EV | Best. Size for future usage, save from day one |
| Solar WITH EV (same time) | Great. Coordinate sizing, single installation process |
| EV first, solar later | Workable but more expensive. Lost savings + expansion costs |
| EV without solar (CA) | Expensive. May cost more than gas at SDG&E rates |
| Action Item | Recommendation |
|---|---|
| Planning EV in next 12 months | Go solar now, size for future usage |
| Already have EV | Go solar immediately, size for current usage |
| Adding second EV | Consider solar expansion or battery to optimize |
| Unsure about EV timing | Size system with EV capacity, add panels later if needed |
Frequently Asked Questions
How much extra solar do I need for an EV?
Most EVs require 2.5-4 kW of additional solar capacity, depending on driving habits. Average driver (12,000 miles/year) should add about 3 kW to their system.
Can I charge my EV directly from solar panels?
Not directly—power flows through your home's electrical system. But during sunny hours, your solar production effectively powers your EV charger. With a battery, you can store daytime production for evening/overnight charging.
What if I get a second EV later?
Mention this during your solar consultation. It's cheaper to oversize now than expand later. Adding capacity for a second EV costs $3,000-5,000 less when included in the original installation.
Is Level 2 charging required for solar + EV?
Highly recommended. Level 1 charging is too slow to take advantage of daytime solar production. Level 2 lets you add meaningful range during sunny hours.
Do I need a bigger electrical panel for solar + EV?
Possibly. Many homes need a panel upgrade (100A to 200A) to accommodate both. A good solar company assesses this during consultation and includes it in the quote if needed.
Can I use my EV battery to power my home?
Some EVs support Vehicle-to-Home (V2H) bidirectional charging. Ford F-150 Lightning and some Hyundai/Kia models offer this. It's an emerging technology—check if your specific EV supports it.
Ready to Plan Your Solar + EV Future?
Whether you already have an EV, are shopping for one, or planning to buy in the next few years, now is the time to get your solar consultation.
We'll help you:
- Size a system for your current AND future usage
- Evaluate battery options for maximum EV charging efficiency
- Calculate your total savings (gas + electricity)
- Coordinate EV charger installation with solar
Free consultation, no pressure. Just honest numbers for your specific situation.
[Get Your Free Solar + EV Consultation] | [Calculate Your Combined Savings]
Silva Bros Solar — Helping California families power their homes AND their cars with sunshine.
