Twenty Years Later Solar Power Cars Remain Elusive

Few people will argue about the desirability of having a car that can drive by gas stations and leave no pollution behind, yet solar power cars have not become very popular. The solar cells are very fragile, they generate a small amount of power and motors powered in solar power cars produce too small an amount of horsepower to make them efficient.

For about 20 years the annual race of solar power cars runs in Australia from Darwin to Adelaide, a trip of about 1,877 miles at top speed of nearly 62 miles per hour. These races are part of the World Solar Challenge with teams from many major universities and corporate enterprises competing. During the first race of solar power cars in 1987, top speed was just 42 miles per hour and is run to promote research into solar powered vehicles.

There are few efficient applications of solar power cars in use, however a few golf carts are run by solar power and they can recharge while sitting in the sunlight each year. Part of the problem is that the number of solar cells attached to the vehicle is limited by the vehicles size and the motors they operate are generally between two and five horsepower. Batteries are still to heavy to be able to receive enough power to push their weight as well as the weight of the vehicle and operator.

Batteries Work Same As Fuel Tank

Batteries within solar power cars serve much the same purpose as a gas tank on convention cars. While lead-acid batteries are more efficient and easier to connect, the power to weight ratio makes them a reluctant choice in solar power cars. Nickle-cadmium, lithium ion and lithium cadmium batteries have a better range, but are more difficult to incorporate into the vehicles electrical system. Typically, solar power cars require between 80 and 170 volts to operate.

While hybrid vehicles using gas or diesel engines are growing in popularity, hybrid bicycles using solar power and human peddle power have also grown recently. Being able to get a vehicle moving by human energy before adding power from solar energy is now being viewed as a possibility for solar power cars. Except, instead of using human power, stored battery operated motors are being used.

Since there are no established designs for solar power cars many designers are focused strictly on reduced drag. This has brought about development of many vehicles bearing a strong resemblance to airplanes.