building solar car

Not only is the sun a source of heat and light, it's a source of electricity too! Solar cells, also called photovoltaic cells, are used to convert sunlight to electricity. Solar cells are used to provide electricity all kinds of equipment, from calculators and watches to roadside emergency phones and recreational vehicles.

Solar cells are most commonly made from silicon, the same material used to make computer chips. Silicon is one of the Earth's most common elements, and is a major component of sand and many kinds of rocks. A solar cell is built like a sandwich, with two layers of silicon separated by a thin layer of insulating material. All three layers work together to convert sunlight into electricity.

The makeup of a solar cell. The Pembina Institue

When sunlight falls onto the solar cell, it produces a small electric charge. Like a battery, the charge is positive on one side of the cell, and negative on the other. A wire connects the two sides of the cell, allowing electricity to flow. This flow, or current, of electricity can be used to power a small light bulb, turn an electric motor, or recharge a battery.

Solar cells are often used in locations where there isn't any electricity and where electricity is needed in small amounts. In such cases, solar cells are usually connected to batteries, allowing electricity to be stored for use during times when the sun isn't shining.

A completed solar car. The Pembina Institute

A single solar cell is able to produce only a small amount of electricity. But solar cells can be connected together on a multi-cell panel to produce larger amounts of electricity. As with batteries, the more cells that are connected to one another, the greater the current of electricity that can be produced.¹ Solar panels can produce enough electricity to power satellites, recreational vehicles, and equipment for other applications where electricity is used in large amounts.

For this project, you will be using the electricity from solar panels to power a small car. Your challenge will be to build a solar car that travels as fast and straight as possible.

¹ Solar cells connected in series (in a long chain, positive to negative, etc.) will increase the voltage of the panel. Solar cells connected in parallel (all their positive terminals to one wire, and all their negative terminals to another wire) will increase the current, or amperage of the panel. In most large commercial panels, the individual cells are connected both ways, with rows of cells in series to raise the voltage of the panel, and then those rows connected to each other in parallel, to raise the amperage.

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