Solar panels can generate electricity as long as there is light, so it is feasible to charge automobile batteries with solar panels in theory.
But why didn’t new energy vehicles adopt this scheme in real life? In fact, there is still a certain gap between theory and practice. Although solar panels can generate electricity as long as there is light, when the power generation is too small, it has no practical significance. In terms of the 70kwh capacity of the battery pack of new energy vehicles, the power generated by the solar panel on the roof is a drop in the bucket. A day in the sun only increases the endurance by a few kilometers!
How big can the roof be? The roof area determines the power of solar panels. Most cars can only put down one square meter of solar panels on the roof, and they have to be thin-film panels. If the conversion efficiency of the battery board is 15%, a square meter of the battery board can emit 150wh of electricity in the noon sun for an hour. If the conversion efficiency reaches 20%, it can emit 200wh of electricity in the noon sun for an hour.
It is not only the conversion rate of solar panels, but also the light intensity that affects the power generation. If you look at the solar power station carefully, you will find that the solar panels are placed at a certain angle. The latitude of different regions is different, and the placement angle of solar panels is also different. For most parts of China, the latitude is high, and the angle of sunlight is oblique.
Therefore, you want the sunlight to shine vertically on the solar panels, then solar panels should also maintain a certain horizontal angle, and even keep changing directions (running after the sun). Some with servo systems can run after the sun.
In most cases, the light intensity is relatively good between 10 a.m. and 3 p.m., so the solar panel should face southeast as much as possible and maintain an inclination angle of 30 ° ~ 60 °, so as to maximize power generation.
It can be seen that the conversion rate of solar panels will be further reduced after being placed on the car roof. After all, the car has no way to change the placement angle of solar panels. Therefore, it is conservatively estimated that the daily power generation of solar panels on the car roof is about 500-800wh, while in areas with good light, it may reach about 1kwh.
Even if all 1kwh of electricity is charged into the battery, it is only one tenth of the battery capacity. For electric vehicles with a power consumption of 15-20kwh per hundred kilometers, 1kwh of electricity can only travel 5-6km!
And solar panels also have a long life. In the environment with poor heat dissipation, the conversion rate will decay quickly!
It can be seen that the installation of solar panels can not significantly improve the mileage, so only some cars specially built for environmental protection will consider the installation of solar panels!
At present, in the case of low conversion rate of solar panels, reducing vehicle power consumption can use solar panels for power supply, which also has a certain practical significance. For example, the power consumption of low-speed electric tricycle is relatively small, and the power consumption per 100 km is only 3-5 kwh.
In this case, if two solar panels are installed on the roof with a daily charging capacity of 1.5kwh, it can last more than 30km. For friends who travel tens of kilometers a day, it is meaningful to refit. As long as there is the sun, there is no need to consider the charging problem.
