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The Pros and Cons of Using Solar Energy for Cars

by Marie-Luise Blue

The development of environmentally friendly cars includes hybrid, electric and solar-powered cars. Although hybrid and electric cars share the roads with gasoline-powered cars, solar-powered cars are built mostly as race cars with races taking place at the American Solar Challenge in North America or the World Solar Challenge in the Australian Outback. A family car named "Stella," created by Dutch engineers, made its debut at an October 2013 race. The successful race of "Stella," a car that can accommodate four people, suggests that it may be possible to overcome the design and energy challenges that plague passenger solar-powered cars so far.

How Solar Cars Work

Solar-powered cars use photovoltaic solar panels to get their "fuel" or energy from the sun. The solar panels are mounted on top of the car to collect sunlight. The sun's energy moves electrons around in the photovoltaic panels, generating electricity. The electricity, generated by the solar panels, powers the electric motor and other car equipment that needs energy. Excess electricity, generated during sunny periods, are stored in a battery for nighttime use or cloudy periods.

Environmentally Friendly

The development of solar-powered cars is attractive, because it does not use a non-renewable resource, such as gasoline, and it does not pollute the atmosphere. Solar-powered cars, unlike fossil fuel-powered cars, do not emit greenhouse gases that contribute to global warming. The electricity that is produced does not cause any greenhouse gas emissions and other pollutants as electricity does that is generated by coal-fired or fossil fuel-powered plants. Solar cars are also very quiet and so do not contribute to noise pollution.


You don't have to purchase fuel for a solar car -- sunlight is free. Even plug-in electric cars have to pay for charging their batteries. Because solar cars have fewer moving parts, they also need less regular maintenance service than conventional cars. Although fuel and maintenance of solar cars is low, at present, the initial cost of a solar car is high. Efficient batteries are expensive and need to be replaced frequently. Replacement of damaged photovoltaic panels is also costly. When the cost of efficient solar panels and batteries comes down, a solar car may be a more practical option.

Energy Availability

Although the sun provides unlimited energy, it does not always shine. During overcast periods or periods of precipitation, the battery may not have enough stored energy to run the solar car. Unlike electric cars, you will not be able to charge the battery during nighttime or sunless days. Another problem is the efficiency of the photovoltaic panels. So far, the efficiency of converting sunlight into electricity by the photovoltaic solar panels ranges between 15 to 30 percent, depending on the material used. More efficient solar panels will reduce the surface area required on the car and produce more horsepower for the car.

Design Challenge

Solar cars look very different from conventional cars. They need a large surface area on top for their solar panels to catch as much sunlight as possible. To make the car energy-efficient, all parts have to be as light as possible and use material such as aluminum and lightweight composites. Efficient and light-weight batteries are best, however, at present the best batteries, are heavy, expensive and need frequent recycling. Although solar cars may become the cars of the future, the ability of solar cars to function at night and during cloud cover and the demonstration of their road-worthiness, such as speed and safety, are needed.

Photo Credits

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