Charging an electric car with solar panels: is it really worth it?
If you own or are thinking about buying an electric car, you’ve probably asked yourself this question:
Can I charge my electric car with solar panels at home?
The short answer is yes, and it can also become one of the most profitable decisions you make in your home.
In Spain, where many areas enjoy more than 2,500 hours of sun per year, combining solar energy + home battery + smart charger makes it possible to drastically reduce the cost per kilometer, increase your energy independence and make the most of your photovoltaic installation. According to the IDAE, residential self-consumption continues to grow in Spain.
But there are important nuances: installing solar panels alone isn’t enough. To achieve a truly efficient system, you need smart energy management.
In this guide we explain how it works, how much it costs, how much you can save and what you need to charge your electric car with solar energy.
Can you charge an electric car with solar energy alone?
Yes, technically it’s possible.
Solar panels generate electricity in direct current (DC), which is converted to power your home or your charging point.
The energy can:
- go directly to the car when there’s solar production
- be stored in a home battery to use later
- be combined with the grid if you need occasional support
This allows much—or even all—of your vehicle’s charge to come from the sun.
Real example in Spain
An average driver covers around 12,000–15,000 km per year.
An electric car consumes approximately:
15–20 kWh / 100 km
That means an annual consumption of:
1,800–3,000 kWh
An average residential solar installation can produce:
4,000–8,000 kWh / year
Conclusion: A well-sized photovoltaic installation can cover a large part of the car’s and the home’s consumption at the same time.
How much it costs to charge an electric car with solar panels
Let’s look at the numbers.
Charging from the grid
If you pay:
€0.18 / kWh
and your car consumes:
17 kWh / 100 km
cost:
€3.06 / 100 km
For 15,000 km:
€459 / year
Charging with solar panels
The marginal cost of that energy is very low once the installation is paid off.
It can be around:
€0.03–0.07 / kWh
cost:
€0.51–1.19 / 100 km
For 15,000 km:
€76–178 / year
Potential savings
€280–€380 per year on mobility alone, in addition to the home’s energy savings.
If you add home + climate control + EV: the annual savings can multiply.
What you need to charge your car with solar energy
1) Solar panels
The foundation of the system.
The usual range:
3 kWp – 8 kWp
depending on:
- household consumption
- car usage
- climate control
- roof orientation
2) Smart charger (Wallbox)
Not just any charger will do.
It must be able to:
✅ adjust power automatically
✅ prioritize solar surplus
✅ schedule charging
✅ balance household consumption
✅ communicate with the energy system
This maximizes self-consumption.
3) Home battery (optional, but recommended)
It lets you store the day’s solar surplus to charge at night.
Advantages:
- greater independence
- more self-consumption
- less purchasing from the grid
- indirect solar charging at night
The best way to charge an electric car with solar panels is to combine a battery
The mistake many people make
Thinking:
“I’ll put up panels and then charge the car for free.”
Problem: solar production doesn’t always coincide with charging time.
If you get home at 9:00 p.m.:
- there’s no sun
- you draw from the grid
- you waste the day’s surplus
The solution: smart energy management
A smart system can automatically decide:
- when to charge the battery
- when to charge the car
- when to draw from the grid
- when to sell surplus
- how to take advantage of dynamic tariffs
This is where brands like Bexie Energy can stand out, with integrated ecosystems of panel + battery + charger + energy software.
Is it profitable to charge an electric car with solar panels in Spain?
In most homes: yes.
Especially if:
✅ you drive more than 10,000 km/year
✅ you have a detached house
✅ you can install solar
✅ you have a time-of-use tariff
✅ you’re looking for energy independence
Frequently asked questions
How many panels do I need to charge an electric car?
Usually between 4 and 8 panels can cover a large part of your annual mobility, depending on usage.
Can I charge it at night?
Yes, with a home battery or grid support.
Do I need to change my contracted power capacity?
It depends on the charger and the home’s simultaneous consumption.
Is it worth it without a battery?
Yes, although a battery makes much better use of the energy generated.
Charging an electric car with solar panels isn’t just possible: it’s one of the most efficient and economical ways to get around in Spain. But the real leap isn’t only about installing panels. It’s about managing energy intelligently. Because the future isn’t only about producing energy. It’s about knowing when to use, store and optimize it.
