Reducing the CO₂ footprint: This is how climate-friendly the electric car becomes with solar power

Electric vehicles are more climate-friendly than combustion engines – but their CO₂ footprint depends on the source of electricity used for charging. In this article, discover why the combination of electric cars and solar power is the most sustainable solution.

The number of registered electric cars in Europe is rising steadily and is making a significant contribution to reducing CO₂ emissions. The transport sector is the third largest polluter after the energy sector and industry. Electric cars can emit up to 79% less CO₂ than conventional combustion engines, but their actual savings potential depends on several factors: battery production, the source of the charging electricity, the vehicle's energy consumption, annual mileage and service life. The biggest factor in achieving a climate-friendly balance lies in the power source – electric cars are only as clean as the electricity they are charged with. Depending on the electricity mix, those who use grid electricity can have a significantly higher carbon footprint than expected. The best solution? The combination of an electric car and your own solar system. With self-generated solar power, you can significantly reduce your carbon footprint while actively driving forward the energy transition in your own household.

The power source as a key factor

Every year, around 600 million tons of CO₂ are generated by human activities in Germany - cars are responsible for over half of these emissions - but there are significant differences between the various drive types. A study by the Association of German Engineers (VDI) from 2024 shows the total CO₂ balance over the life cycle of a vehicle:

• Diesel: 33 tons of CO₂

• Petrol engine: 37 tons of CO₂

• Electric car with grid power: 24 tons of CO₂

The advantage of electric vehicles over combustion engines is obvious – but the actual CO₂ savings depend crucially on the origin of the charging power. While the proportion of renewable energies in Germany is growing steadily and coal-fired power generation is declining, the CO₂ impact of grid electricity remains comparatively high. Since 2014, CO₂ emissions from electricity generation have halved from 312 to around 152 million tons per year – significant improvement. Nevertheless, a look at the emissions figures shows that conventional grid electricity still has a comparatively high CO₂ impact. The average emission factor of grid electricity is currently around 344 g CO₂ equivalents per kilowatt hour, while solar power from your own photovoltaic system only generates between 40 and 100 g CO₂ equivalents per kilowatt hour, depending on the system and location. Although not every kilometer driven can be directly covered by solar power - for example due to grid feed-in, charging times or use outside PV production times - every kilowatt hour of self-generated solar power reduces dependence on grid power and thus CO₂ emissions. So if you charge your electric car with self-generated solar energy, you can not only reduce your mobility costs, but also make a significant contribution to reducing transport-related emissions.

Calculation example: Savings potential for an electric car in Germany

For an average electric car driver, e.g. with a VW ID.4 with a mileage of 15,000 km per year and an assumed consumption of 17 kWh per 100 km (= 2,550 kWh), the following values result:

• Charging with grid power:
  2.550 kWh × 0,344 kg CO₂/kWh = 877,2 kg CO₂/year

• Charging with solar power (with CO₂ emissions of 100 g CO₂/kWh):

  2.550 kWh × 0,1 kg CO₂/kWh= 255 kg CO₂/year

• CO₂ savings potential compared to grid power:

  877 kg CO₂− 255 kg CO ₂= 622 kg CO₂/year

• Reduction: 71% less CO₂ emissions than with grid power

In addition to the environmental benefits, the combination of solar system and electric car offers further decisive advantages such as cost savings, independence and grid relief. Solar power from your own roof is cheaper than grid electricity. While households currently pay around 30 cents/kWh for grid electricity, the self-consumption price of solar power is often less than 10 cents/kWh. An average solar household can cover around 60-70% of its e-car electricity requirements with self-generated solar power – which means significantly lower mobility costs in the long term. In addition, fossil fuels are becoming increasingly expensive: On January 1, 2025, the CO₂ price for petrol, diesel, heating oil and gas was increased from 45 to 55 euros per tonne of CO₂. Driving a car with an internal combustion engine is becoming increasingly expensive. The use of self-generated solar power can make households less dependent on the electricity grid and relieve the burden on grid expansion in the short term. However, in some cases, feeding solar power into the grid without storage can lead to local grid fluctuations. Only with intelligent load management or battery storage can decentralized energy generation make an effective contribution to reducing peak loads and ensuring grid stability.

Conclusion: Why the combination of solar + EV is the future 

Electric cars are a key component of sustainable mobility - but they only reach their full potential with renewable electricity. With your own solar power, you can not only drastically reduce CO₂ emissions, but also keep energy costs stable in the long term. In view of rising prices for fossil fuels, falling PV system costs and growing government incentives, it is becoming increasingly attractive for households to generate their own electricity. Investing in a solar system now will give you more independence and actively shape the future of clean and affordable mobility.

Elli has teamed up with PV provider OTOVO to offer customers this savings potential and create a seamless ecosystem for sustainable mobility and energy. The company is the perfect partner in all matters relating to photovoltaics and is by your side every step of the way.

Spring campaign: €1,000 discount for Elli customers on OTOVO solar systems

Elli customers receive a €1,000 discount on their OTOVO solar system as part of the spring campaign. The offer applies to all customers who come to OTOVO via Elli and the discount is automatically deducted from the purchase price – regardless of whether it is a pure PV system or whether a storage system or wallbox is also included.

• Regardless of the configuration: The discount applies to every system, whether with or without storage/wallbox.

• No further conditions: The only requirement is that the customer comes to OTOVO via Elli.

• Valid for purchase and rental: When purchasing, the amount is deducted directly from the total price of the system. When renting, the purchase price of the system is reduced by €1,000, which affects the monthly rental installments over 20 years.

Get a PV quote now and save with the power of the sun!

Text: OTOVO