Like many race cars, the driver's cockpit usually only contains room for one person, although a few cars do contain room for a second passenger. They contain some of the features available to drivers of traditional vehicles such as brakes, accelerator, turn signals, rear view mirrors (or camera), ventilation, and sometimes cruise control. A radio for communication with their support crews is almost always included.
Solar cars are often fitted with gauges as seen in conventional cars. Aside from keeping the car on the road, the driver's main priority is to keep an eye on these gauges to spot possible problems. Cars without gauges available for the driver will almost always feature wireless telemetry. Wireless telemetry allows the driver's team to monitor the car's energy consumption, solar energy capture and other parameters and free the driver to concentrate on just driving.
Many solar race cars have complex data acquisition systems that monitor the whole electrical system while even the most basic cars have systems that provide information on battery voltage and current to the driver.
The mechanical systems of a solar car are designed to keep friction and weight to a minimum while maintaining strength. Designers normally use titanium and composites to ensure a good strength-to-weight ratio.
Solar cars usually have three wheels, but some have four. Three wheelers usually have two front wheels and one rear wheel: the front wheels steer and the rear wheel follows. Four wheel vehicles are set up like normal cars or similarly to three wheeled vehicles with the two rear wheels close together.
The solar array can be mounted in several ways:
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.
The two most notable solar car races are the World Solar Challenge and the North American Solar Challenge, overland road rally-style competitions contested by a variety of university and corporate teams.
The World Solar Challenge features a field of competitors from around the world who race to cross the Australian continent, over a distance of 3000 km. The increasingly high speeds of the 2005 race participants has led to the rules being changed for future solar cars starting in the 2007 race.
The North American Solar Challenge, previously known as the 'American Solar Challenge' and 'Sunrayce USA', features mostly collegiate teams racing in timed intervals in the United States and Canada. This race also changed rules for the most recent race due to teams reaching the regulated speed limits. The most recent North American Solar Challenge ran from June 13-22, 2008, from Dallas, Texas to Calgary, Alberta. The next race is expected to run in the summer of 2010.
There are other distance races, such as Suzuki, Phaethon, and the World Solar Rally. Suzuki
is a yearly track race in Japan and Phaethon was part of the Cultural Olympiad in Greece right before the 2004 Olympics.
Solar photovoltaics assisted electric powered India's first Quadricycle developed since 1996, in Gujarat state's SURAT city.
The first solar "cars" were actually tricycles or quadricycles built with bicycle technology. These were called solarmobiles at the first solar race, the Tour de Sol in Switzerland in 1985 with 72 participants, half using exclusively solar power and half solar-human-powered hybrids. A few true solar bicycles were built, either with a large solar roof, a small rear panel, or a trailer with a solar panel. Later more practical solar bicycles were built with foldable panels to be set up only during parking. Even later the panels were left at home, feeding into the electric mains, and the bicycles charged from the mains. Today highly developed electric bicycles are available and these use so little power that it costs little to buy the equivalent amount of solar electricity. The "solar" has evolved from actual hardware to an indirect accounting system. The same system also works for electric motorcycles, which were also first developed for the Tour de Sol. This is rapidly becoming an era of solar production.
In May 2007 a partnership of Canadian companies lead by Hymotion altered a Toyota Prius to use solar cells to generate up to 240 watts of electrical power in full sunshine. This is reported as permitting up to 15 km extra range on a sunny summer day while using only the electric motors.
One practical application for solar powered vehicles is possibly golf carts, some of which are used relatively little but spend most of their time parked in the sun.
An inventor from Michigan, USA has built a street legal, licensed, insured, solar charged electric scooter. It has a top speed controlled at a bit over 30 mph, and uses fold-out solar panels to charge the batteries while parked.
A Swiss project, Solartaxi, seeks to circumnavigate the world. The first time in history a solar powered vehicle is going around the world, covering 50000 km in 18 months and crossing 40 countries. It is a road-worthy solar car with a trailer, carrying a 6 m² sized solar array. The Solartaxi has Zebra batteries, which permit a range of 400 km without recharging. The car can also run for 200 km without the trailer. Its maximum speed is 90 km/h. The car weighs 500 kg and the trailer weighs 200 kg. According to team leader Louis Palmer, the car in mass production could be produced for 6000 Euro. Solartaxi is touring the World from July 2007 till December 2008 to show that solutions to stop global warming are available and to encourage people in pursuing alternatives to fossil fuel.
An interesting variant of the electric vehicle is the triple hybrid vehicle-- the PHEV that has solar panels as well to assist.
The 2009 Toyota Prius will have an option to mount solar panels on the roof. They will provide an additional 300 Watts of charge while parked, and also act as a sun shade.