A solar car is a solar vehicle for use on public roads or race tracks. Solar vehicles are electric vehicles that use self-contained solar cells to provide full or partial power to the vehicle via sunlight. Solar vehicles typically contain a rechargeable battery to help regulate and store the energy from the solar cells and from regenerative braking. Some solar cars can be plugged into external power sources to supplement the power of sunlight used to charge their battery. Solar cars combine technology typically used in the aerospace, bicycle, alternative energy and automotive industries. The design of solar vehicles always emphasizes energy efficiency to make maximum use of the limited amount of energy they can receive from sunlight. Most solar cars have been built for the purpose of solar car races. However several prototypes of solar cars designed for use on public roads have been designed and built. There are various solar car competitions around the world that are generally partaken by collegiate and company teams. The most notable competitions is the World Solar Challenge, which is an international competition that takes place in Australia. Some other competitions include the American Solar Challenge and the United Solar Challenge. As of December 2022, only one solar car had reached production, the Lightyear 0, but at the limited delivery rate of one car a week. In January 2023 the company halted vehicle manufacture and sales, and the vehicle maker's production company, Atlas Technologies B.V., requested bankruptcy protection. The Aptera solar/plug in car production was expected to start in 2025. The com-any states production is delayed, and as of June, 2026 only 5 “Validation Vehicles” have been produced. Solar cars depend on a solar array that uses photovoltaic cells (PV cells) to convert sunlight into electricity. Unlike solar thermal energy which converts solar energy to heat, PV cells directly convert sunlight into electricity. When sunlight (photons) strike PV cells, they excite electrons and allow them to flow, creating an electric current. PV cells are made of semiconductor materials such as silicon and alloys of indium, gallium and nitrogen. Crystalline silicon is the most common material used and has an efficiency rate of 15–25%.
History The first model solar car was the Sunmobile, a tiny 15-inch vehicle created by General Motors employee William G. Cobb. He displayed it in 1955 at the Chicago Powerama convention. It was made up of 12 selenium photovoltaic cells and a small electric motor. In 1962 the International Rectifier Company added a solar panel to a 1912 Baker Electric, and unveiled the first solar car that could carry passengers.
Solar array The solar array consists of hundreds of solar cells converting sunlight into electricity. In order to construct an array, PV cells are placed together to form modules which are placed together to form an array. The larger arrays in use can produce over 2 kilowatts (2.6 hp).
The solar array can be mounted in six ways:
horizontal. This most common arrangement gives most overall power during most of the day in low latitudes or higher latitude summers and offers little interaction with the wind. Horizontal arrays can be integrated or be in the form of a free canopy. vertical. This arrangement is sometimes found in free standing or integrated sails to harness wind energy. Useful solar power is limited to mornings, evenings, or winters and when the vehicle is pointing in the right direction. adjustable. Free solar arrays can often be tilted around the axis of travel in order to increase power when the sun is low and well to the side. An alternative is to tilt the whole vehicle when parked. Two-axis adjustment is only found on marine vehicles, where the aerodynamic resistance is of less importance than with road vehicles. integrated. Some vehicles cover every available surface with solar cells. Some of the cells will be at an optimal angle whereas others will be shaded. trailer. Solar trailers are especially useful for retrofitting existing vehicles with little stability, e.g. bicycles. Some trailers also include the batteries and others also the drive motor. remote. By mounting the solar array at a stationary location instead of the vehicle, power can be maximised and resistance minimized. The virtual grid-connection however involves more electrical losses than with true solar vehicles and the battery must be larger. The choice of solar array geometry involves an optimization between power output, aerodynamic resistance and vehicle mass, as well as practical considerations. For example, a free horizontal canopy gives 2-3 times the surface area of a vehicle with integrated cells but offers better cooling of the cells and shading of the riders. There are also thin flexible solar arrays in development. Solar arrays on solar cars are mounted and encapsulated very differently from stationary solar arrays. Solar arrays on solar cars are usually mounted using industrial grade double-sided adhesive tape right onto the car's body. The arrays are encapsulated using thin layers of Tedlar. Some solar cars use gallium arsenide solar cells, with efficiencies around thirty percent. Other solar cars use silicon solar cells, with efficiencies around twenty percent.
Batteries The battery pack in a typical solar car is sufficient to allow the car to go 250 miles (400 km) without sun, and allow the car to continuously travel at speeds of 60 mph (97 km/h).
Motors The motors used in solar cars typically generate about 2 or 3 horsepower, yet experimental light solar cars may attain the same speed as a typical family car (100 mph (160 km/h)).
Races
… excerpt ends here. Continue reading the full article.
