Solar cars have gained a lot of interest in recent years as companies like Toyota and Lightyear have brought new solar car elements to the market. With Toyota offering a Prius with a solar array on the roof, and Lightyear promising a full solar vehicle in 2019, the world of solar cars is rapidly changing.
What Is A Solar Car?
A solar car is a type of vehicle used for ground transportation that is powered by the use of solar panels. Many models also used a battery so that power can be stored until it is needed to power the vehicle or one of the other auxiliary systems that are on board.
The solar array found on a solar car uses photovoltaic cells (PV cells) to harness the sunlight and convert it into usable electricity. PV cells can be made from a blend of semiconductive materials including silicon, gallium, indium, and nitrogen. Crystalline silicon is currently the most common material employed in the making of PV cells and solar arrays.
While solar thermal heat converts sunlight directly into heat for various uses, a solar array on an electric car converts sunlight into electricity by exciting electrons contained in the PV cells. These excited electrons then flow through pre-determined channels and a current of electricity is formed.
Today solar cars come in all shapes and sizes as newer technology and different design elements are implemented and experimented with. New technology, in particular, has allowed solar cars to become differently shaped than their predecessors, move faster, and cover longer distances.
Solar cars are not yet in dealerships and it may be some time before you can freely purchase one for conventional transportation, however people have been building their own models since the 1970’s.
In the past, solar cars have appeared regularly at automotive shows and were labeled as concept cars. Ford and Mazda have both created solar concept cars for shows, and the French car company Venturi has been very public about the prototype that was displayed at the Paris Auto Show in 2006.
How Are Solar Cars Made?
It is unlikely that you’ll find solar cars being mass produced in factories anytime soon. However, the desire to reduce our dependence on gasoline has sparked many creative individuals to figure out how to make a solar-powered car. How solar cars work will vary based on design, but they are frequently made by people with little to no vehicle building experience.
Hybrid solar cars are another popular option because they are able to utilize various fuels and are able to travel much more efficiently than gas-powered vehicles. Solar, battery power, and wind are the three most commonly combined systems and they seem to work quite well despite having some challenges.
Solar cars must be lightweight in order to carry passengers and use their power source most efficiently. While regular cars can weigh several thousand pounds, solar vehicles can weigh in at under 1000 pounds or even much less.
Teams from across the country come together to figure out how to build a better solar car with the knowledge and materials they have at their disposal. They also gather to compete at different locations all across the world. While these competitions are great for sparking further innovation and knowledge sharing, they are also an important resource for amateur builders.
There are several different kinds of solar arrays now available for solar car enthusiasts and how they work can determine the success of the vehicle. The configuration of PV cells on solar panels can vary in direction while the angle of the solar array must also be optimal in relation to the location of the sun.
Practical considerations, as well as aerodynamics and power output, are all things that are considered when planning how a solar car will be built. Solar arrays may be attached using industrial strength double-sided tape, or other mounting hardware can be used.
The Inner Workings of Solar Cars
Despite solar panels having come a long way in recent years, batteries are still advised and widely used in solar cars today. A fully charged battery can carry the average solar vehicle for approximately 250 miles without any help from the sun and still keep an average speed of 60 mph.
While solar cars are impressive, they still have some progress to make before becoming commercially available. Cars that run on strictly solar power are not yet feasible for the general public due to limitations on the efficiency of solar panels, but with a battery to assist, many cars are now more efficient.
The extra boost to a solar car that a fully charged battery can provide has been found to add up to 220 kilometers according to some engineering students in Europe. While Toyota is still working on their Prius model that has solar panels on the roof, university teams around the world are pushing the limits of solar-powered vehicles and how they work.
Solar cars also contain a number of gauges that help the driver identify issues before they are cause for concern. While the number of gauges present can vary, in most cases it will be more than you would find on your standard gasoline powered vehicle.
Monitoring the power used by a solar vehicle as you drive can be very important when figuring out how far you will be able to travel. The same is true regarding the amount of power collected via the solar panels that replenish the power stored in the battery.
Modern solar cars may have wireless telemetry which allows an individual to monitor the car which leaves the driver free to concentrate on driving. This wireless telemetry is popular in solar car racing, and there are even models that do not require a human driver to be in the car.
How Does A Solar Car Stop or Accelerate?
How a solar car stops is very similar to how a conventional car would stop, but with lighter hardware. Since the aerodynamics and weight of a solar car are very important factors to consider, the hardware is chosen appropriately and somewhat resembles that of conventional brakes on a car.
Amateur builders and solar race car teams may choose to use different hardware in order to each meet their unique goals, but acceleration uses some kind of motor that will likely be electric. The motor may only be 2 or 3 horsepower, but it can be sufficient to reach speeds as high as 100 mph.
Building Solar Cars
You may have seen a solar car in the past and wondered how it worked, and in truth, the exact method will largely depend on the design. Different builders will choose different shapes for their solar vehicles which will directly impact how it works on the road.
Lightweight frames and skins are used to cut down on weight, and very thin solar panels are frequently used. These may be adhered with industrial tape or mounted on small brackets.
The direction of the solar panel in relation to the sun is important and at any given time a portion of the solar panel will need to be perfectly positioned in order to produce the maximum amount of power possible.
Tires are also used; however, they are slightly different and more lightweight than the ones mounted on modern cars. Lighter rims and highly durable lightweight tires are frequently used and may resemble a thick bike tire.
Where the driver sits will vary widely, but unless there is remote monitoring, the driver’s seat will have gauges and other mechanisms to provide feedback about the workings of the solar car. Seats will be another item that will undoubtedly be chosen for its weight, and there may or may not be a seatbelt.
When building a solar car, aerodynamics matter as the performance of the vehicle will be directly affected. Body shape and weight distribution will also need to be considered, and different kinds of software exist to help create a digital design and also run simulations to gauge performance.
Solar cars frequently use the best that technology has to offer and how they work will largely depend on the performance of this technology and its particular application. Solar panels are consistently becoming more efficient and are able to create more power from a smaller space. This increase in efficiency is part of what drives improvements to solar cars.
The use of different materials is another factor that may limit the performance of a solar car, and different builders have their own mix of materials that they find work best with their design. If a solar vehicle is eventually going to be mass produced it is likely that the materials would need to be easy and cost-effective to procure in bulk.
No one is better acquainted with the limitations of solar cars than the many teams all over the globe that design them with the intent to enter long distance and speed races. These races are fiercely competitive, and solar cars are regularly tested to find their limitations. Several races occur each year, and solar car racing teams have gained popularity in engineering schools in the US.