Why don't new energy vehicles use solar power to charge the car?

This is a beautiful-looking brain-hole problem that is difficult to achieve in reality. Then, this may be an answer in the future and become a reality. Why do you say that? Let's look down. Let us first focus on who applies solar energy technology best: the world's solar energy technology is used to drive cars, and the most extreme thing is the SunSwif team. They built a solar-powered sports car called eVe in 2012, which was approved by the Australian government in 2016 and allowed to go on the road legally. 1 The car can travel at a speed of 99.7km/h for more than 482.8km per hour, which is better than the Tesla Model S85D that traveled the same distance at a speed of 88.5km/h that year (2014). In a single full-charge test, it traveled 500km at an average speed of 106.966km/h, breaking the world record. eVe is exposed to direct sunlight for 8 hours (no cloudy, unobstructed, and full of sunshine). The solar panel with a conversion efficiency of 22.7% can exert a maximum power of 800W. The stored electric energy can support the vehicle to drive for 2 hours. 2 At the same time, the car's own weight is only 317kg, the body is made of TeXtreme carbon fiber, the wheels are made of carbon fiber and aluminum, and the Panasonic battery pack has a weight of 59kg. Obviously, this is a car that is extremely lightweight and exists in order to brush records. Lightweight is one aspect. Adding as many solar panels as possible to absorb more energy is the most fundamental task of the car. 3 Despite such efforts in lightweight and maximum power development of solar panels, eVe is exposed to the blazing sun 8 Hours, it can only provide 2 hours of driving guarantee (no matter what speed it is driving, and whether the car supports plug-in charging, only in the solar energy category), this performance index can not meet people's daily travel needs (the sunshine time cannot Guaranteed and too long, it is difficult to ensure that the parking place is unobstructed). Moreover, the cost of building eVe is extremely high. The SunSwif team spent $500,000 to develop it successfully, and mass production is only in the process of exploring. Seeing this, you will probably understand why the question asked in the question is a brain-inspired question. Among the mass-produced models, there are indeed models that use solar energy technology, but they realize other functions. Take the opportunity here. Introduce it to everyone. First of all, mass-produced new energy vehicles that apply solar energy technology can't bypass the Toyota Prius, which has a cumulative global sales volume of over 10 million (only 76 units were sold in China in 2016, which is a huge contrast, which is also a scene). 4 On a global scale, Prius, which has formed a huge influence, relies on its hybrid technology to realize the characteristics of low fuel consumption and high cost performance. At the same time, it has the courage to try other energy-saving applications, including solar sunroofs. Prius's solar sunroof application principle is very simple, just look at the picture below. 5 It looks like a great presentation, but in fact, you will encounter a lot of inconveniences in the process of using it. For example, solar power can only start the blower to exchange the air inside and outside the car, that is to say, replace the hotter air inside the car with hot air outside the car, which cannot achieve the cooling effect. Furthermore, to use the remote control key to start the air conditioner remotely, one condition must be met, that is, the Ni-MH battery pack must have a power of 3 bars or more before it can be started. Each start only works for 3 minutes in order to protect the battery life. In this case, the use scene is limited, and it is difficult to greatly reduce the temperature in the car. In addition, the solar sunroof will stop starting due to conditions such as weather, sunshine, and presence or absence of obstructions. 6 Seemingly beautiful configuration, it can be used, and the cooling effect will be there, but there are too many restricted conditions, and the actual experience cannot be achieved in one step. The reason is that the solar power is unable to start the air-conditioning compressor, which is related to the maximum power of the solar sunroof and the photoelectric conversion efficiency related. The picture below shows a list of important solar technologies. 7 The solar sunroof material used by Prius is polycrystalline silicon battery with an area of u200bu200b0.405 square meters and a unit conversion efficiency of 16.5% (less than 19% in the table). The maximum output power of the entire panel is only 56W, and the power of the car air-conditioning compressor is at least Above 2kW, the gap is too great to be able to drive it at all. Even if the monocrystalline silicon HIT technology solar sunroof recently cooperated by Toyota and Panasonic, the maximum power is only 180W, which is also far from the power of driving the air-conditioning compressor (only 12V 8.8kWh capacity car lithium-ion battery can be charged). In fact, as early as 1992, Mazda 929 models have been equipped with solar cells to supply electricity for the fans. After that, the Audi A6 Allroad, the first generation of Skoda Haorui top equipment, Ford's C-MaxSolarEnergi concept car and other models are all equipped with solar energy. Battery, but unfortunately, the function is nothing more than power supply for the fan. 8 Recently, there has been news about solar cell technology. Audi announced that it has cooperated with Alta Devices, a wholly-owned subsidiary of Hanergy Group in the United States, to develop thin-film solar cell technology. It uses the highest cost gallium arsenide battery in the above table, photoelectric The conversion efficiency is the highest. It is estimated that the solar panel power is about 300W. Based on the cumulative maximum power generation in a year of 400-500kWh, it is enough to drive the vehicle to travel 2600-3300km, while the annual mileage of general vehicles is about 15000km. 9 It can be seen that in the short term, it is unrealistic for new energy vehicles to rely solely on solar power to drive. It is feasible to use as auxiliary energy to extend the range or save fuel consumption. Under the global trend of the deep application of new energy, various car companies have set up production and sales schedules for new energy vehicles. Perhaps, the energy utilization methods presented in the future will become less unitary based on technological breakthroughs and comprehensive utilization. Maybe, Today's brain-hole questions will be transformed and become the answer in the near future.