A solar vehicle or solar electric vehicle is an
electric vehicle powered completely or significantly by direct
solar energy. Usually,
photovoltaic (PV) cells contained in
solar panels convert the
sun
The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
's energy directly into
electric energy
Electrical energy is energy related to forces on electrically charged particles and the movement of electrically charged particles (often electrons in wires, but not always). This energy is supplied by the combination of electric current and electr ...
. The term "solar vehicle" usually implies that solar energy is used to power all or part of a vehicle's
propulsion
Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived f ...
.
Solar power
Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Photovoltaic cells convert light into an electric current using the photovolta ...
may be also 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 (PV) 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 Solar car racing refers to competitive races of electric vehicles which are powered by solar energy obtained from solar panels on the surface of the car (solar cars). The first solar car race was the Tour de Sol in 1985 which led to several simila ...
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
In fluid dynamics, the drag coefficient (commonly denoted as: c_\mathrm, c_x or c_) is a dimensionless quantity that is used to quantify the drag or resistance of an object in a fluid environment, such as air or water. It is used in the drag e ...
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 (2 to 3 hours) 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
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...
, to commercialize this technology. An American company,
Aptera Motors
Aptera Motors (formerly Accelerated Composites) is an American startup high-efficiency car company based in Carlsbad, California.
The original company, Aptera Motors, Inc., was founded in 2005 and liquidated in 2011.
In 2019, Aptera Motors w ...
, has also been founded to make efficient solar electric cars for the public. In Germany the company
Sono Motors is working on their solar electric vehicle, the
Sono Motors Sion
Sion is an announced solar powered, full electric car, currently being developed by the German start-up Sono Motors. Its battery can be charged using the electric grid or its own solar cells.
History
The founders of Sono Motors have been workin ...
, that is supposed to be on the market in 2023.
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.
Solar buses
Solar buses are propulsed by solar energy, all or part of which is collected from stationary solar panel installations. The
Tindo
A solar bus or solar-charged bus is a bus that is powered exclusively or mainly by solar energy. Solar-powered bus service is referred to as a solar bus service. The use of the term "solar bus" normally implies that solar energy is used not only ...
bus is a 100% solar bus that operates as
free public transport
Free public transport, often called fare-free public transit or zero-fare public transport, refers to public transport funded in full by means other than by collecting fares from passengers. It may be funded by national, regional or local gover ...
service in
Adelaide
Adelaide ( ) is the capital city of South Australia, the state's largest city and the fifth-most populous city in Australia. "Adelaide" may refer to either Greater Adelaide (including the Adelaide Hills) or the Adelaide city centre. The dem ...
City as an initiative of the City Council. Bus services which use
electric bus
An electric bus is a bus that is propelled using electric motors as opposed to an internal combustion engine. Electric buses can store the needed electricity on-board, or be fed continuously from an external source. The majority of buses ...
es 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
Idle reduction describes technologies and practices that minimize the amount of time drivers idle their engines. Avoiding idling time has a multitude of benefits including: savings in fuel and maintenance costs, extending vehicle life, and redu ...
laws that are in force in several of the US states, and can be retrofitted to existing vehicle batteries without changing the conventional engine.
Single-track vehicles
![Wolfurt-solar E-Bicycle-01ASD](https://upload.wikimedia.org/wikipedia/commons/3/35/Wolfurt-solar_E-Bicycle-01ASD.jpg)
The first solar "cars" were actually tricycles or
Quadracycle
A quadracycle is a four-wheeled human-powered land vehicle. It is also referred to as a quadricycle, quadcycle, pedal car or four-wheeled bicycle amongst other terms.
Quadracycles have been in use since 1853 and have grown into several fami ...
s built with bicycle technology. These were called solarmobiles at the first solar race, the
Tour de Sol
The Tour de Sol in Switzerland was the first rally for solar powered vehicles. It was carried out annually from 1985 to 1993. The first event started on June 25 in Romanshorn on the Lake of Constance, and finished on June 30 in Geneva. 72 vehic ...
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
An electric bicycle (e-bike, eBike, etc.) is a motorized bicycle with an integrated electric motor used to assist propulsion. Many kinds of e-bikes are available worldwide, but they generally fall into two broad categories: bikes that assist ...
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
The Tour de Sol in Switzerland was the first rally for solar powered vehicles. It was carried out annually from 1985 to 1993. The first event started on June 25 in Romanshorn on the Lake of Constance, and finished on June 30 in Geneva. 72 vehic ...
.
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
The is a car built by Toyota which has a hybrid drivetrain, combining an internal combustion engine with an electric motor. Initially offered as a four-door sedan, it has been produced only as a five-door liftback since 2003.
In 2007, ...
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 unit
An auxiliary power unit (APU) is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft and naval ships as well as some large land vehicles. Aircraft APUs generally produce 115& ...
s 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
The is a car built by Toyota which has a hybrid drivetrain, combining an internal combustion engine with an electric motor. Initially offered as a four-door sedan, it has been produced only as a five-door liftback since 2003.
In 2007, th ...
,
Aptera 2,
Audi A8, and
Mazda 929
The Mazda 929 is a full-size car which was sold by the Japanese automobile manufacturer Mazda between 1973 and 1997. Mazda used the 929 nameplate for export markets only, badge engineering
In the automotive industry, rebadging is a form of ...
have had solar
sunroof
A sunroof is a movable panel that opens to uncover a window in an automobile roof, allowing light and fresh air to enter the passenger compartment. Sunroofs can be manually operated or motor driven, and are available in many shapes, sizes and styl ...
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 m
2 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
The Fisker Karma is a luxury plug-in range-extended electric sports sedan produced by Fisker Automotive in 2012. The cars were manufactured at Valmet Automotive in Finland.
The United States Environmental Protection Agency (EPA) rated th ...
, available as an option on the
Chevy Volt
The Chevrolet Volt is a plug-in hybrid manufactured by General Motors, also marketed in rebadged variants as the Holden Volt in Australia and New Zealand and the Buick Velite 5 in China, and with a different fascia as the Vauxhall Ampera in th ...
, on the hood and roof of "Destiny 2000" modifications of
Pontiac Fiero
The Pontiac Fiero is a mid-engine sports car manufactured and marketed by Pontiac for model years 1984-1988. Designed by George Milidrag and Hulki Aldikacti as a sports car, it was the first two-seater Pontiac since the 1926 to 1938 coupes, an ...
s,
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
The is a car built by Toyota which has a hybrid drivetrain, combining an internal combustion engine with an electric motor. Initially offered as a four-door sedan, it has been produced only as a five-door liftback since 2003.
In 2007, ...
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 CO
2 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, (specifically
thermophotovoltaic
Thermophotovoltaic (TPV) energy conversion is a direct conversion process from heat to electricity via photons. A basic thermophotovoltaic system consists of a hot object emitting thermal radiation and a photovoltaic cell similar to a solar cell b ...
(TPV) 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 (e.g. GaSb). A prototype TPV hybrid car was even built. The "Viking 29" was the World's first thermophotovoltaic (TPV) powered automobile, designed and built by the Vehicle Research Institute (VRI) 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 (PRT) 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 (AC) 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.
The Kismaros – Királyrét narrow-gauge line near Budapest has built a solar powered railcar called 'Vili'. With a maximum speed of 25 km/h, 'Vili' is driven by two 7 kW motors capable of regenerative braking and powered by 9.9m2 of PV panels. Electricity is stored in on-board batteries. In addition to on-board solar panels, there is the possibility to use stationary (off-board) panels to generate electricity specifically for use in transport.
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 (Bachet de Pesay). The 150 kW
p 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
Imperial College London (legally Imperial College of Science, Technology and Medicine) is a public research university in London, United Kingdom. Its history began with Prince Albert, consort of Queen Victoria, who developed his vision for a cu ...
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 CO
2.
Water
![Tûranor PlanetSolar Rabat](https://upload.wikimedia.org/wikipedia/commons/a/a0/T%C3%BBranor_PlanetSolar_Rabat.JPG)
Solar powered boats have mainly been limited to rivers and canals, but in 2007 an experimental 14 m catamaran, the Sun21 sailed the Atlantic from
Seville
Seville (; es, Sevilla, ) is the capital and largest city of the Spanish autonomous community of Andalusia and the province of Seville. It is situated on the lower reaches of the River Guadalquivir, in the southwest of the Iberian Peninsula ...
to Miami, and from there to New York. It was the first crossing of the Atlantic powered only by solar.
Japan's biggest shipping line Nippon Yusen KK and
Nippon Oil Corporation
, formerly , or NOC or ''Shin-Nisseki'' (新日石) is a Japanese petroleum company. Its businesses include exploration, importation, and refining of crude oil; the manufacture and sale of petroleum products, including fuels and lubricants; and ...
said solar panels capable of generating 40 kilowatts of electricity would be placed on top of a 60,213 ton
car carrier
Roll-on/roll-off (RORO or ro-ro) ships are cargo ships designed to carry wheeled cargo, such as cars, motorcycles, trucks, semi-trailer trucks, buses, trailers, and railroad cars, that are driven on and off the ship on their own wheels or usin ...
ship to be used by
Toyota Motor Corporation
is a Japanese multinational automotive manufacturer headquartered in Toyota City, Aichi, Japan. It was founded by Kiichiro Toyoda and incorporated on . Toyota is one of the largest automobile manufacturers in the world, producing about 10 ...
.
In 2010, the
Tûranor PlanetSolar
MS ''Tûranor PlanetSolar'', known under the project name ''PlanetSolar'', founded by the Swiss explorer Raphaël Domjan, is the largest solar-powered boat in the world and launched on 31 March 2010. It was designed and engineered by LOMOcean ...
, a 30-metre long, 15.2-metre wide
catamaran yacht powered by 470 square metres of solar panels, was unveiled. It is, so far, the largest solar-powered boat ever built. In 2012, PlanetSolar became the first ever solar electric vehicle to
circumnavigate
Circumnavigation is the complete navigation around an entire island, continent, or astronomical body (e.g. a planet or moon). This article focuses on the circumnavigation of Earth.
The first recorded circumnavigation of the Earth was the Magel ...
the globe.
Various demonstration systems have been made. Curiously, none yet takes advantage of the huge power gain that water cooling would bring.
The low power density of current solar panels limits the use of solar propelled vessels; however boats that use sails (which do not generate electricity unlike combustion engines) rely on battery power for electrical appliances (such as refrigeration, lighting and communications). Here solar panels have become popular for recharging batteries as they do not create noise, require fuel and often can be seamlessly added to existing deck space.
Air
![Flea Hop HB-SIA - Solar Impulse](https://upload.wikimedia.org/wikipedia/commons/c/cc/Flea_Hop_HB-SIA_-_Solar_Impulse.jpg)
Solar ships can refer to solar powered airships or hybrid airships.
There is considerable military interest in
unmanned aerial vehicle
An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controll ...
s (UAVs); solar power would enable these to stay aloft for months, becoming a much cheaper means of doing some tasks done today by satellites. In September 2007, the first successful flight for 48h under constant power of a UAV was reported.
This is likely to be the first commercial use for photovoltaics in flight.
Many demonstration solar aircraft have been built, some of the best known by
AeroVironment.
Manned solar aircraft
*
Gossamer Penguin
The ''Gossamer Penguin'' was a solar-powered experimental aircraft created by Paul MacCready's AeroVironment. MacCready, whose ''Gossamer Condor'' had made the first human-powered flight in 1977, told reporters two weeks in June, 1980 that "The ...
*
Solar Challenger
The Solar Challenger was a solar-powered electric aircraft designed by Paul MacCready's AeroVironment. The aircraft was designed as an improvement on the Gossamer Penguin, which in turn was a solar-powered variant of the human-powered Gossamer ...
– This aircraft flew from Paris, France, to England on solar power.
*
Sunseeker Duo
*
Solar Impulse
Solar Impulse is a Swiss long-range experimental solar-powered aircraft project, and also the name of the project's two operational aircraft. The privately financed project is led by Swiss engineer and businessman André Borschberg and Swiss ...
– two single-seat aircraft, the second of which circumnavigated the Earth. The first aircraft completed a 26-hour test flight in Switzerland on 8–9 July 2010. The aircraft was flown to a height of nearly by
André Borschberg. It flew overnight using battery power. The second aircraft, slightly larger and more powerful, took off from
Abu Dhabi in 2015, flew towards India and then eastward across Asia. However, after experiencing battery overheating, it was forced to halt in Hawaii over the winter. In April 2016, it resumed its journey, and completed its circumnavigation of the globe, returning to Abu Dhabi on 26 July 2016.
*
SolarStratos – Swiss stratospheric 2-seater solar plane aims to climb to the stratosphere.
*
Solair – Solair I and Solair II are two German-designed electric aircraft.
Hybrid airships
Unmanned aerial vehicles
*
Pathfinder and Pathfinder-Plus – This UAV demonstrated that an airplane could stay aloft for an extended period of time fueled purely by solar power.
*
Helios – Derived from the Pathfinder-Plus, this
solar cell
A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon. and
fuel cell powered UAV set a world record for flight at .
*
Qinetiq Zephyr
The Airbus Zephyr is a series of lightweight solar-powered unmanned aerial vehicles (UAV). The latest model is a high-altitude platform station capable of flying at for months at a time without fueling. It has a wingspan of and weighs .
Deve ...
– built by Qinetiq, this UAV set the unofficial world record for longest duration unmanned flight at over 82 hours on 31 July 2008. Just 15 days after the Solar Impulse flight mentioned above, on 23 July 2010 the Zephyr, a lightweight
unmanned aerial vehicle
An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controll ...
engineered by the United Kingdom defence firm
QinetiQ, claimed the endurance record for an unmanned aerial vehicle. It flew in the skies of Arizona for over two weeks (336 hours). It has also soared to (.
* China's designed and manufactured UAV successfully reached an altitude of during a test flight in the country's northwest regions. Named "Caihong" (CH), or "Rainbow" in English, it was developed by a research team from
CASC.
Future projects
* The
BAE Systems PHASA-35 being developed by
BAE Systems & aerospace technology firm Prismatic for test flights in 2019.
* Titan Aerospace acquired by Google aimed to develop the Solar UAV, however the project seems to be abandoned
*
Sky-Sailor (aimed at Martian flight)
* Various solar airship projects, such as Lockheed Martin's "High Altitude Airship"
Space
Solar powered spacecraft
Solar energy is often used to supply power for satellites and spacecraft operating in the inner solar system since it can supply energy for a long time without excess fuel mass. A
Communications satellite
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth ...
contains multiple radio transmitters which operate continually during its life. It would be uneconomic to operate such a vehicle (which may be on-orbit for years) from primary
batteries or
fuel cells, and refuelling in
orbit
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as ...
is not practical. Solar power is not generally used to adjust the satellite's position, however, and the useful life of a communications satellite will be limited by the on-board station-keeping fuel supply.
Solar propelled spacecraft
A few spacecraft operating within the orbit of
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...
have used solar power as an energy source for their propulsion system.
All current solar powered spacecraft use
solar panels in conjunction with
electric propulsion
Spacecraft electric propulsion (or just electric propulsion) is a type of spacecraft propulsion technique that uses electrostatic or electromagnetic fields to accelerate mass to high speed and thus generate thrust to modify the velocity of a sp ...
, typically
ion drive
An ion thruster, ion drive, or ion engine is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions using electricity.
An ion thruster ionizes a neutral gas by extracting some electrons out of ...
s as this gives a very high exhaust velocity, and reduces the propellant over that of a
rocket
A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...
by more than a factor of ten. Since propellant is usually the biggest mass on many spacecraft, this reduces launch costs.
Other proposals for solar spacecraft include
solar thermal
Solar thermal energy (STE) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in industry, and in the residential and commercial sectors.
Solar thermal collectors are classified by the United S ...
heating of propellant, typically hydrogen or sometimes water is proposed. An
electrodynamic tether
Electrodynamic tethers (EDTs) are long conducting wires, such as one deployed from a tether satellite, which can operate on electromagnetism, electromagnetic principles as electrical generator, generators, by converting their kinetic energy to ele ...
can be used to change a satellite's orientation or adjust its orbit.
Another concept for solar propulsion in space is the
light sail
Solar sails (also known as light sails and photon sails) are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large mirrors. A number of spaceflight missions to test solar propulsion and navigation have been p ...
; this doesn't require conversion of light to electrical energy, instead relying directly on the tiny but persistent
radiation pressure
Radiation pressure is the mechanical pressure exerted upon any surface due to the exchange of momentum between the object and the electromagnetic field. This includes the momentum of light or electromagnetic radiation of any wavelength that is a ...
of light.
Planetary exploration
Perhaps the most successful solar-propelled vehicles have been the "rovers" used to explore surfaces of the Moon and Mars. The 1977
Lunokhod programme
Lunokhod ( rus, Луноход, p=lʊnɐˈxot, "Moonwalker") was a series of Soviet robotic lunar rovers designed to land on the Moon between 1969 and 1977. Lunokhod 1 was the first roving remote-controlled robot to land on an extraterrestria ...
and the 1997
Mars Pathfinder
''Mars Pathfinder'' (''MESUR Pathfinder'') is an American robotic spacecraft that landed a base station with a roving probe on Mars in 1997. It consisted of a lander, renamed the Carl Sagan Memorial Station, and a lightweight, wheeled robot ...
used solar power to propel remote controlled vehicles. The operating life of these rovers far exceeded the limits of endurance that would have been imposed, had they been operated on conventional fuels. The two
Mars Exploration Rover
NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, '' Spirit'' and '' Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rovers to explore the Martian surface ...
s also used solar power.
Electric vehicle with solar assist
A Swiss project, called "Solartaxi", circumnavigated the world. This was the first time in history an electric vehicle (not self sufficient solar vehicle) had gone around the world, covering 50000 km in 18 months and crossing 40 countries. It was a road-worthy electric vehicle hauling a trailer with solar panels, 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 initiator and tour director
Louis Palmer, the car in mass production could be produced for 16000 Euros. Solartaxi toured 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. Palmer suggests the most economical location for solar panels for an electric car is on building rooftops though, likening it to putting money into a bank in one location and withdrawing it in another.
Solar Electrical Vehicles is adding convex solar cells to the roof of hybrid electric vehicles.
Plug-in hybrid and solar vehicles
An interesting variant of the electric vehicle is the triple hybrid vehicle—the
PHEV
A plug-in hybrid electric vehicle (PHEV) is a hybrid electric vehicle whose battery pack can be recharged by plugging a charging cable into an external electric power source, in addition to internally by its on-board internal combustion engin ...
that has solar panels as well to assist.
The 2010
Toyota Prius
The is a car built by Toyota which has a hybrid drivetrain, combining an internal combustion engine with an electric motor. Initially offered as a four-door sedan, it has been produced only as a five-door liftback since 2003.
In 2007, ...
model has an option to mount solar panels on the roof. They power a ventilation system while parked to help provide cooling. There are many applications of photovoltaics in transport either for motive power or as
auxiliary power unit
An auxiliary power unit (APU) is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft and naval ships as well as some large land vehicles. Aircraft APUs generally produce 115& ...
s, particularly where fuel, maintenance, emissions or noise requirements preclude internal combustion engines or fuel cells. Due to the limited area available on each vehicle either speed or range or both are limited when used for motive power.
Limitations
There are limits to using photovoltaic (PV) cells for vehicles:
* Power density: Power from a solar array is limited by the size of the vehicle and area that can be exposed to sunlight. This can also be overcome by adding a flatbed and connecting it to the car and this gives more area for panels for powering the car. While energy can be accumulated in batteries to lower peak demand on the array and provide operation in sunless conditions, the battery adds weight and cost to the vehicle. The power limit can be mitigated by plugging in and recharging the batteries from the electrical grid.
* Cost: While sunlight is free, PV cells to capture that sunlight is not. However the cost of solar cells declined by 99% in 4 decades and their cost is expected to continue to drop.
* Design considerations: Even though sunlight has no lifespan, PV cells do. In the 1980's the lifetime of a solar module was approximately 30 years.
Stationary photovoltaic panels then often came with a warranty of 90% (from nominal power) after 10 years and 80% after 25 years. Mobile applications are unlikely to require lifetimes as long as building integrated PV and solar parks. To be successful in mobile applications, PV panels need to be designed to withstand vibrations.
See also
*
Electric aircraft
*
Electric boat
*
Frisian Solar Challenge
The Frisian Solar Boat Challenge is a solar boat race.
The race starts in Leeuwarden, the capital of Friesland, and follows the classic route of the Eleven City Tour. Following the canals, rivers, and lakes, with the occasional portage, the rac ...
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Kit car
A kit car is an automobile available as a set of parts that a manufacturer sells and the buyer then assembles into a functioning car. Usually, many of the major mechanical systems such as the engine and transmission are sourced from donor ve ...
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List of solar car teams
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List of prototype solar-powered cars
This list of prototype solar-powered cars comprises multiperson, relatively practical vehicles powered completely or significantly by solar cells ( panels or arrays, mounted on the vehicle) which convert sunlight into electricity to drive electri ...
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Plug-in hybrid
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Solar balloon
A solar balloon is a balloon that gains buoyancy when the air inside is heated by solar radiation, usually with the help of black or dark balloon material. The heated air inside the solar balloon expands and has lower density than the surrounding ...
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Solar Golf Cart
A golf cart (alternatively known as a golf buggy or golf car) is a small motorized vehicle designed originally to carry two golfers and their golf clubs around a golf course with less effort than walking. Over time, variants were introduced t ...
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South African Solar Challenge
The Sasol Solar Challenge is a South African endurance challenge for solar-powered vehicles, with classes for hybrid vehicles, electric vehicles, and biofuel-powered vehicles as well. Recognised by the International Solarcar Federation, the f ...
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Sunmobile
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The Quiet Achiever
The Quiet Achiever, also known as the Holden Solar Trek, was the world's first practical long-distance solar-powered car powered entirely by photovoltaic solar cells.
The project was promoted by adventurer Hans Tholstrup, with the Australian-m ...
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Tour de Sol
The Tour de Sol in Switzerland was the first rally for solar powered vehicles. It was carried out annually from 1985 to 1993. The first event started on June 25 in Romanshorn on the Lake of Constance, and finished on June 30 in Geneva. 72 vehic ...
References
External links
{{DEFAULTSORT:Solar Vehicle
Photovoltaics