Solar vehicle
A solar electric vehicle is an electric vehicle powered completely or significantly by direct solar energy. Usually, photovoltaic cells contained in solar panels convert the sun's energy directly into electric energy.
A concentrated solar vehicle uses stored solar energy to run a heat engine, such as Rankine, Stirling or Brayton cycle, of the piston and crank type directly powering the vehicle or a powering a hybrid electric car system.
The term "solar vehicle" usually implies that solar energy is used to power all or part of a vehicle's propulsion. Solar power may also be used to provide power for communications or controls or other auxiliary functions.
Solar vehicles are not sold as practical day-to-day transportation devices at present, but are primarily demonstration vehicles and engineering exercises, often sponsored by government agencies. However, indirectly solar-charged vehicles are widespread and solar boats are available commercially.
Land
Solar cars
Solar cars are electric cars that use photovoltaic cells to convert sunlight into electrical power to charge the car's battery and to power the car's electric motors.Solar cars have been designed for solar car races and for public use. Solar vehicles must be light and efficient to get the best range from their limited captured power. pound or even vehicles would be less practical because the limited solar power would not take them as far. Most student built solar cars lack the safety and convenience features of conventional vehicles and are thus not street legal.
The first solar family car, Stella, was built in 2013 by students in the Netherlands. This vehicle is capable of on one charge during sunlight. It weighs and has a 1.5 kWh solar array.
Stella Lux, the successor to Stella, broke a record with a single-charge range. During racing Stella Lux is capable of during daylight. At Stella Lux has infinite range. This is again due to high efficiency including a Coefficient of drag of 0.16.
The average family who never drive more than a day would never need to charge from the mains. They would only plug in if they wanted to return energy to the grid.
Solar race cars are often fitted with gauges and/or wireless telemetry, to carefully monitor the car's energy consumption, solar energy capture and other parameters. Wireless telemetry is typically preferred as it frees the driver to concentrate on driving, which can be dangerous in such a car without safety features. The Solar Electric Vehicle system was designed and engineered as an easy to install integrated accessory system with a custom molded low profile solar module, supplemental battery pack and charge controlling system.
Some of the students that built Stella Lux founded a company, Lightyear, to commercialize this technology.
An American company, Aptera Motors, has also been founded to make efficient solar electric cars for the public. As of January 2023, first customer availability is expected in 2024.
In Germany the company Sono Motors was working on a solar electric vehicle, the Sono Motors Sion, that was supposed to be on the market in 2023. However in February 2023, Sono Motors terminated the Sion program and announced it would focus exclusively on being a Solar Tech Company.
Note that all battery-powered electric vehicles may also use external solar array sourced electricity to recharge. Such arrays may also be connected to the general electrical distribution grid.
File:Squad Solar Car.jpg|thumb|right|Squad Solar neighborhood Electric Vehicle
Squad Solar is a neighborhood Electric Vehicle Side-by-side with a solar roof and can be charged relatively quickly from a normal outlet.
Solar buses
Solar buses are propulsed by solar energy, all or part of which is collected from stationary solar panel installations. The Tindo bus is a 100% solar bus that operates as free public transport service in Adelaide City as an initiative of the City Council. Bus services which use electric buses that are partially powered by solar panels installed on the bus roof, intended to reduce energy consumption and to prolong the life cycle of the rechargeable battery of the electric bus, have been put in place in China.Solar buses are to be distinguished from conventional buses in which electric functions of the bus such as lighting, heating or air-conditioning, but not the propulsion itself, are fed by solar energy. Such systems are more widespread as they allow bus companies to meet specific regulations, for example the anti-idling laws that are in force in several of the US states, and can be retrofitted to existing vehicle batteries without changing the conventional engine.
Solar semi trailers
Solar panels on semi trailers has been tested. There is over 100 square meters or over 1,000 square feet of surface area for solar on a 53 foot box trailer, on the top and sides.Single-track vehicles
The first solar "cars" were actually tricycles or Quadracycles 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 used solar power exclusively while the other half used 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.
Applications
The Venturi Astrolab in 2006 was the world's first commercial electro-solar hybrid car, and was originally due to be released in January 2008.In May 2007 a partnership of Canadian companies led 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.
An inventor from Michigan, USA built a street legal, licensed, insured, solar charged electric scooter in 2005. It had a top speed controlled at a bit over 30 mph, and used fold-out solar panels to charge the batteries while parked.
Auxiliary power
Photovoltaic modules are used commercially as auxiliary power units on passenger cars to ventilate the car, reducing the temperature of the passenger compartment while it is parked in the sun. Vehicles such as the 2010 Prius, Aptera 2, Audi A8, and Mazda 929 have had solar sunroof options for ventilation purposes.The area of photovoltaic modules required to power a car with conventional design is too large to be carried on board. A prototype car and trailer has been built called Solar Taxi. According to the website, it is capable of 100 km/day using 6 m2 of standard crystalline silicon cells. Electricity is stored using a nickel/salt battery. A stationary system such as a rooftop solar panel, however, can be used to charge conventional electric vehicles.
It is also possible to use solar panels to extend the range of a hybrid or electric car, as incorporated in the Fisker Karma, available as an option on the Chevy Volt, on the hood and roof of "Destiny 2000" modifications of Pontiac Fieros, Italdesign Quaranta, Free Drive EV Solar Bug, and numerous other electric vehicles, both concept and production. In May 2007 a partnership of Canadian companies led by Hymotion added PV cells to a Toyota Prius to extend the range. SEV claims per day from their combined 215 Wh module mounted on the car roof and an additional 3 kWh battery.
On 9 June 2008, the German and French presidents announced a plan to offer a credit of 6–8 g/km of CO2 emissions for cars fitted with technologies "not yet taken into consideration during the standard measuring cycle of the emissions of a car". This has given rise to speculation that photovoltaic panels might be widely adopted on autos in the near future.
It is also technically possible to use photovoltaic technology, to provide motive power for a car. Fuel is used to heat an emitter. The infrared radiation generated is converted to electricity by a low band gap PV cell. A prototype TPV hybrid car was even built. The "Viking 29" was the World's first thermophotovoltaic powered automobile, designed and built by the Vehicle Research Institute at Western Washington University. Efficiency would need to be increased and cost decreased to make TPV competitive with fuel cells or internal combustion engines.
Personal rapid transit
Several personal rapid transit concepts incorporate photovoltaic panels.Rail
Railways present a low rolling resistance option that would be beneficial for planned journeys and stops. PV panels were tested as APUs on Italian rolling stock under EU project PVTRAIN. Direct feed to a DC grid avoids losses through DC to AC conversion. DC grids are only to be found in electric powered transport: railways, trams and trolleybuses. Conversion of DC from PV panels to grid alternating current was estimated to cause around 3% of the electricity to be wasted.PVTrain concluded that the most interest for PV in rail transport was on freight cars where on-board electrical power would allow new functionality:
- GPS or other positioning devices, so as to improve its use in fleet management and efficiency.
- Electric locks, a video monitor and remote control system for cars with sliding doors, so as to reduce the risk of robbery for valuable goods.
- ABS brakes, which would raise the maximum velocity of freight cars to 160 km/h, improving productivity.
A few pilot projects have also been built in the framework of the "Heliotram" project, such as the tram depots in Hannover Leinhausen and Geneva. The 150 kWp Geneva site injected 600 V DC directly into the tram/trolleybus electricity network provided about 1% of the electricity used by the Geneva transport network at its opening in 1999. On 16 December 2017 a fully solar-powered train was launched in New South Wales, Australia. The train is powered using onboard solar panels and onboard rechargeable batteries. It holds a capacity for 100 seated passengers for a 3 km journey.
Recently Imperial College London and the environmental charity 10:10 have announced the Renewable Traction Power project to investigate using track-side solar panels to power trains. Meanwhile, Indian railways announced their intention to use on-board PV to run air conditioning systems in railway coaches. Also, Indian Railways announced it is to conduct a trial run by the end of May 2016. It hopes that an average of 90,800 liters of diesel per train will be saved on an annual basis, which in turn results in reduction of 239 tonnes of CO2.