If you have both an electric car and solar panels, you have hit the jackpot of the energy transition. But only if you can also charge your car with your solar panels. And that’s where smart charging comes in.
The problem with solar panels
Solar panels produce the most electricity during the day, when the sun shines. But most people work during the day and use little electricity at home. The surplus is returned to the grid.
That used to be attractive, thanks to the netting scheme. You got the same price for return as for purchase. But the netting scheme is being phased out. From 2025 you only get a fraction of the purchase price for your return.
Example:
– You buy electricity for €0.30 per kWh
– You return electricity for €0.05 per kWh
– Difference: €0.25 per kWh wasted
That hurts. Especially if you have invested thousands of euros in solar panels.
The solution: charge with your own solar power
With an electric car you have a perfect solution: a big battery that can store your solar power. A typical electric car has a battery of 60-80 kWh – enough to store the production of a sunny day.
But there’s a catch: most people drive to work during the day. And if your car is not at home, you can’t charge it with your solar panels.
Or can you?
Three scenarios for solar charging
Scenario 1: You work from home or are often at home during the day
Then it’s simple. Plug the car in during the day and let Stekker automatically charge when your solar panels produce. The app knows how much your panels produce and charges your car with exactly that power.
You don’t use the grid, save the difference between return and purchase price, and drive on free solar power.
Scenario 2: You work at the office
More difficult, but not impossible. Many offices nowadays have charging stations. If you can charge there (preferably for free or cheaply), you can shift your home consumption to the evening.
Your solar panels then power your home appliances during the day, instead of your car. Effectively you still use your solar power, just indirectly.
Scenario 3: You charge publicly
If you charge on the street, it becomes more difficult. But even then Stekker can help: the app shows when solar and wind energy is abundant and electricity is cheap. By charging at those times, you still use mainly green energy.
How much do you save?
Let’s calculate for someone who drives 15,000 km per year (= 3,000 kWh charging):
Without smart charging:
– You return 3,000 kWh @ €0.05 = €150
– You buy 3,000 kWh @ €0.30 = €900
– Net costs: €750
With smart solar charging:
– You use 3,000 kWh of your own solar power
– Costs: €0 (panels are already paid)
– Savings: €900
– Loss of return income: €150
– Net savings: €750 per year
So: with smart solar charging you save €750 per year compared to returning your solar power and buying expensive electricity.
Bonus: V2G – your car as home battery
The future is even better. With V2G (Vehicle-to-Grid) or V2H (Vehicle-to-Home) your car can not only be charged with solar power, but can also return power to your home in the evening.
Then your car becomes a home battery:
– During the day: charge with solar power
– In the evening: use that power for cooking, washing, etc.
– At night: charge the rest with cheap night-time electricity
This way you use almost all your solar power yourself and buy minimal electricity from the grid.
What do you need?
For smart solar charging you need:
- Solar panels (obviously)
- An electric car
- A smart charging station that can measure solar production
- Software like Stekker that coordinates everything
Stekker supports various ways to measure your solar production:
– Via your inverter (most accurate)
– Via your smart meter
– Via an estimate based on weather data
Get started today
You don’t have to wait for V2G. Smart solar charging works today, with your current car and charging station.
Every kWh you charge with your own solar power is a kWh you don’t have to buy. With current price differences that quickly saves €0.20 to €0.30 per kWh.
And it feels good too: driving on your own solar power, that’s the energy transition in practice.
Have solar panels and an electric car? Download the Stekker app and start using your solar power optimally.
