Energy Energy is one of the most fundamental parts of our universe. We use energy to do work. Energy lights our cities. Energy powers our vehicles, trains, planes and rockets. Energy warms our homes, cooks our food, plays our music, gives us pictures on television. Energy powers machinery in factories. Energy is defined as "the ability to do work." Cars, planes, boats and machinery also transform energy into work. Work means moving something, lifting something, warming something, lighting something. All these are a few of the various types of work. But where does energy come from? There are many sources of energy.
Solar Energy When we hang laundry outside to dry in the sun, we are using the sun's heat to do work -- drying our clothes. The sun has always been an energy source. Plants use the sun's light to make food. Animals eat plants for food. So, fossil fuels actually got their start as sunlight many millions of years ago.
Photovoltaic Cells We can also change the sunlight directly to electricity using solar cells. Solar cells are also called photovoltaic cells -- or PV cells for short -- and can be found on many small appliances, like calculators, and even on spacecraft. They were first developed in the 1950s for use on U.S. space satellites. They are made of silicon, a special type of melted sand.
How Solar Energy Works When sunlight strikes the solar cell, electrons (red circles) are knocked loose. They move toward the treated front surface (dark blue color). An electron imbalance is created between the front and back. When the two surfaces are joined by a connector, like a wire, a current of electricity occurs between the negative and positive sides. The electricity from solar cells can then be used directly.
1. Solar energy is converted directly to electricity by the photovoltaic array. 2. Electric energy is stored in batteries. Solar electricity can also go directly to the motor when the car is running. 3. Modern electronic motor controllers smoothly and efficiently control power to the motor. Speed control is by a normal accelerator pedal. 4. The latest in motor technology uses powerful rare-earth magnets and a brushless design. A 5 hp motor can weigh less than 5 kg. 5. The drive to wheels in advanced vehicles does not need a gearbox. Gear changing is done electronically in the motor.
Using Solar Energy Some experimental cars also use PV cells. They convert sunlight directly into energy to power electric motors on the car. A solar car operates by the collection and conversion of sunlight into electricity. Using solar cells mounted on the vehicle, collected energy is delivered to the car's batteries or motor. Generally, a car can operate on only 700-1500 watts of power.
Team Pegasus-The Beginning Last year, Team Pegasus became the first high school ever in the southeast to compete in the Winston Solar Challenge. The car here today, Pegasus I, started out as some drawings. Such drawings, called schematics, were created by the students.
Evolution The students then used the drawings to gather the components needed for building and racing the car. Many expensive parts were necessary. They had to ask a lot of businesses, small and large, to contribute money for the project. Once the team got all of the parts, they spent months working on assembly.
The Winston Solar Challenge After the car was built, the team entered it in a race across the west; that race was called 1999 Winston Solar Challenge. Many different states and countries were also competing in this special race. It lasted for 7 days, and each day was like a small race. It took a lot of effort to keep the car running; the team members had to give up all of their free time to work on the cars problems. The job was very tiring, but its reward was great. Team Pegasus came in first place on Day 6!
National Recognition Overall, Team Pegasus placed 3rd. They received numerous awards for all of the work they did. The mayors of some cities gave them a city key! Spartanburg City named an entire week Team Pegasus Solar Racing Week. The team went on television, and was photographed for newspapers everywhere. They even have pictures on the Winston Solar Racing Internet Page, not to mention their own web site. There isnt a doubt that Team Pegasus, Mr. Gunter (their sponsor), and all of the outside helpers (like businesses and chaperones) deserve all of the credit for this massive victory!