An increased interest in renewable energy systems has made many automobile companies think in the line of solar-powered cars as a sustainable means of transport. Electric vehicles are cleaner than conventional vehicles. The pollution from electricity used to power cars makes EVs powered by solar energy a better option. Solar cars are electric cars that use solar PV cells to convert solar energy into electricity. It can store in batteries so that the cars can run smoothly at night or in the absence of direct sunlight.
How do solar-powered cars work?
Solar cars are made up of many small solar PV cells which generate electricity. PV cell is sandwiched by semi-conducting material like silicon. When this mixed with phosphorous and boron, gives each side a positive and negative electrical charge, thus creating an electric field between the two layers.
When a photon of sunlight knocks an electron free, the metal conductive plates on the sides of the cell collect the electrons and transfer them to wires. From the wire, electrons can flow like a source of electricity to power the car. There are technological as well as design limitations for a solar car as it won’t be aesthetically appealing. Using the technologies used in the automotive industries the students of the University of New South Wales have developed Sunswift IV for Solar Racing.
Advantages of solar cars
Solar cars have many advantages over conventional ones. It helps to save money on fuel. Solar energy is free and in abundance. The only additional cost is that of battery replacement.
Solar cars are sustainable and environmentally friendly, thus contributing to the betterment of society by fully avoiding the threat of carbon emissions. It creates a pollution-free environment by fully avoiding noise pollution and air pollution.
The first-ever solar-powered car Sunmobile was invented by General Motors in 1955. It was a small 15inch vehicle. It was made of a small Pooley electric motor and 12 selenium photovoltaic cells.
For the next 65 years, this field remained untouched. No one has managed to invent a full-sized commercial vehicle powered only by the sun. In conclusion, Inefficient technology, weather constraints and energy storage were the barriers to the invention of a fully solar-powered car.
First prototype electric car with solar recharging.
Almost half a decade back, German startup Sono Motors created Sion, the world’s first prototype electric car with solar recharging.
Sion is capable of becoming a mobile power storage device giving backup power when necessary. It can recharge itself automatically using solar energy. It is free of cost and without carbon emission. The car has 248 solar PV cells incorporated into its body.
Flexible solar cells charge the car whether its parked or driven. Recharging the vehicle will be 4 times lesser than that of an electric car. Sion’s solar technology is not weather-dependent because they use monocrystalline silicon cells which can produce energy even under cloudy sky conditions.
Their vehicle can capture on average about 16 km worth of solar energy per day if it is positioned well in the sun, kept clean all the time, and the battery is always not full. Sono Motors claims it to be the first commercially available hybrid solar-electric vehicle. It can charge itself using solar power. It takes about 30 minutes to charge up to 80% at a charging station.
Why fully solar-powered cars are not yet a reality?
There are a few reasons why even the most advanced automobile companies couldn’t develop fully solar-powered cars.
Firstly, the low solar panel efficiency. Most of the commercially operated solar panels have only around 20 to 35% efficiency. That won’t suffice travel needs on a low solar day. Secondly, the number of panels to carry in a car is another barrier. It is not feasible packing the cars with solar panels because of their weight and cost. Most importantly, They are very heavy and expensive as well. Solar films are much lighter than panels. But it cannot be used as a replacement as they are less efficient.
Solar cars with solar PV panels can generate approximately 8 kWh of energy per day. However, energy generation depends on various factors like weather conditions, driving conditions, positioning of the panels, and maintenance of panels.
Poor weather condition, improper positioning of panels, and accumulation of dirt would make it impossible to achieve even that 8kWh.
Though solar-powered cars are very sustainable, they aren’t “100%” eco-friendly. Batteries and solar cells carry a share of the carbon footprint as the raw materials are from the Earth.
Technological advancements in the solar car sector
Technological advancements have made significant progress in the field of solar-powered vehicles. As a result, 2020 has witnessed many such innovations. In 2020 Lightyear introduced a prototype of the world’s first long-range solar car, Lightyear One, with strong solar panels, using 83 Wh/km and accelerating from 0-100 in ten seconds.
Besides powering by the sun, the Lightyear One can be charged at a charging station, using a regular 230-volt socket. On a single recharge, it boasts a range of 450 miles. The company is taking pre-orders and is planning to start production by 2021.
This year Hyundai has released its new Sonata hybrid passenger car equipped with a solar roof which helps to charge its battery. On using for 6 hours, the solar roof could replenish 60% of the car’s battery. A solar roof is an extra option. It can also help keep the car’s 12-volt and hybrid batteries charged even when the car is parked. The panels would provide enough power to propel the Sonata for 1,300km a year.
Hybrid cars have small battery packs, so they make maximum benefit out of solar roofs. It would boost fuel efficiency and lower carbon dioxide emissions. They have improved engine control system to ensure efficient energy use.
Hyundai is now working on a second-generation solar roof that would be semi-transparent to help light the car’s cabin. They are working on improving the efficiency of solar panels and the cost for commercial viability.
Research for the technical optimization
The University of York in the U.K. worked towards increasing the ability of solar panels to absorb light by a stunning 125%.
consequently, the same amount of absorber material, ten times more solar power could be generated. They promise lighter, thinner, cheaper, more flexible solar panels.
Current research into low-weight batteries and high-efficiency photovoltaic cells will make solar-powered cars viable in near future.
Attempts to make automobile technology more sustainable in the future by building a fully functioning solar car or its hybrid version has been undertaken by many automakers including Toyota, Hyundai.
Certainly, solar vehicle market is in limelight now. According to some estimates, it could reach $689 billion by 2027. It gives a hope that cars and small vehicles could be fully powered by sun very soon.