The solar car is an electric vehicle equipped with integratedphotovoltaic panels that convert solar energy into electricity to power the vehicle’s engine and auxiliary systems. Thesolar energy generated is stored in on-board batteries, which are used to power the electric motors and ensure driving autonomy. These vehicles combine the advantages of electric cars, such as zero local emissions and low running costs, with the free, renewable energy of the sun. Solar cars have the potential to reduce dependence on fossil fuels and contribute to the fight against climate change, while offering a sustainable alternative for personal and collective mobility.
The need for solar panels and batteries
To estimate the need for solar panels and batteries for a solar-powered car, we need to take into account several factors, such as energy consumption, solar panel efficiency and daily distance travelled. Here’s a simplified example to illustrate the calculation process:
- Energy consumption: Let’s assume that our solar car consumes an average of 15 kWh of energy per 100 km driven.
- Daily distance: Let’s assume that the solar car travels an average of 50 km per day. Daily energy consumption would therefore be 7.5 kWh (15 kWh/100 km * 50 km).
- Solar energy production: Let’s assume that the solar panels installed on the car have an efficiency of 20%, and that average solar irradiation is 1000 W/m² per day. To cover the daily energy consumption of 7.5 kWh, the required surface area of the solar panels would be :
Panel area = Daily energy consumption / (Panel efficiency * Solar irradiation) Panel area = 7.5 kWh / (0.2 * 1 kWh/m²) = 37.5 m²
In practice, such a large surface area of solar panels can be difficult to achieve on a car. Today’s solar cars generally use solar panels to supplement the energy stored in the battery and extend the range.
- Battery capacity: Suppose we wanted our solar car to have a range of 300 km. The required battery capacity would be :
Battery capacity = Energy consumption for 100 km * Desired range distance / 100 km Battery capacity = 15 kWh * 300 km / 100 km = 45 kWh
Solar car projects
Several solar car projects have been developed in recent years, demonstrating the technological advances in this field. Here are a few notable examples:
- The Lightyear One is a solar car developed by Dutch start-up Lightyear. It is designed to be highly efficient in terms of energy and aerodynamics, with a range of over 700 km. Its solar panels, integrated into the roof and hood, generate up to 60 km of additional range per day, depending on sunlight conditions.
- American company Aptera Motors has designed a three-wheeled solar car called the Aptera. Its lightweight, aerodynamic design ensures extremely low energy consumption. The integrated solar panels can generate up to 40 miles (approx. 64 km) of range per day, and the car has a total range of up to 1000 miles (1609 km) on a single battery charge.
- German company Sono Motors has developed the Sion, an electric car equipped with solar panels. The solar panels are integrated into the vehicle’s bodywork, and can generate up to 34 km of additional range per day, depending on sunlight conditions. The Sion also features a two-way charging function, enabling the energy stored in the battery to be used to power other devices or electric vehicles.
- Solar Team Eindhoven: This is a group of students from Eindhoven University of Technology in the Netherlands, who are developing solar cars as part of the World Solar Challenge competition. Their vehicles, such as the Stella Vie and Stella Era, are solar-powered family cars that have won several awards for their innovative design and energy efficiency.