①Solar car
Solar Energy Automobile is a vehicle that uses solar energy as energy to drive. As shown in Figure 1, it has the characteristics of energy saving, safety and environmental protection. Because of its zero pollution and inexhaustible energy, it is called the “Future Car”. Compared with traditional heat engine-driven cars, solar cars are truly “zero emission”. Because of its environmental protection characteristics, solar cars are advocated by many countries, and the development of the solar car industry is also booming. Solar cars are the application of solar power generation in automobiles, which will effectively reduce global environmental pollution and create a clean living environment. With the rapid development of global economy and science and technology, solar cars as an industry are no longer a myth.
Early solar cars were made in Mexico. This kind of car looks like a three-wheeled motorcycle, with a solar cell shed on the roof. Under the sunlight, solar cells supply electric energy to the car, so that the speed of the car can reach
40km/h, because this kind of car can only travel for 40 minutes every day, so it can’t run long distances.

In November 1987, a World Solar Car Rally Competition was held in Australia. 25 solar cars from 7 countries participated in the competition. The total length of the race is 3200km, which runs through almost the entire Australian territory. In this competition, the American solar-powered car “Santa Reisa” ran the course with a time of 44h54min and won the championship. The “Santa Reisa” solar racing car is shown in Figure 2. Although it uses ordinary silicon solar cells, its design is unique and novel. It adopts an airplane-like shape and can use the lift generated by the wings during driving. The weight of the car body was offset, and the motor made of superconducting magnetic material, which was newly developed at that time, was installed, which enabled the car to create the highest record of instantaneous speed of 100km/h in the competition.

The advantages of solar cars are: solar cars use photovoltaics to replace oil, which can save limited petroleum resources, will not emit harmful gases to the atmosphere, and eliminate the pollution of fuel exhaust; solar cars have no internal combustion engine, and you can’t hear the internal combustion engine of a fuel car when driving. The roaring sound; the solar car is easy to drive, does not need electronic ignition, only needs to step on the accelerator pedal to start, the controller is used to change the speed; there is no need to change gears, step on the clutch, simplify the complexity of driving, and avoid operation errors. The hidden dangers of accidents are especially suitable for women and the elderly to drive; the solar car has a simple structure and basically does not need daily maintenance except for the regular replacement of the battery. Therefore, solar cars have aroused great interest from people and will develop rapidly in the future.
The constraints of solar cars: the cost of solar panels is still too high; the energy efficiency of solar panels is still low.
②The application of solar photovoltaic on the highway
It is very expensive to set up a power grid on the expressway. The use of solar photovoltaic power generation to supply power to the necessary power facilities on the expressway is not only energy-saving, environmentally friendly, but also economical and safe.
On highways and in service areas far away from the urban power grid, photovoltaic power stations or photovoltaic-fuel-fueled hybrid systems are built to provide lighting and catering in the service areas. Ground-based photovoltaic arrays or photovoltaic building integration can be used according to the actual situation.
Emergency telephone system: The highway passes through many remote areas. In order to cope with emergencies and emergencies, emergency telephones must be provided as a means of communication. Because of the remote location, the use of solar power does not require long-distance transmission and distribution equipment, there is no transmission loss, and the operation is safe and reliable.
Video monitor: The video monitor is very important to the operation of the highway, and the use of solar power is a novel and reliable way. The solar road monitor is shown in Figure 3.

Solar information billboards: provide traffic information or advertisements, which is also a bright spot of photovoltaic power generation systems applied on highways.
Solar road lights: Mainly used for roadside warning at night on highways and urban streets, and can also be used for decoration points on garden villa roads.