Solar Energy

  Valerie

·        How long have we used the sun’s energy?

·        How have we used solar energy?

·        How does a solar power plant work?

·        What are the advantages and disadvantages?

 

        We have always used the energy of the sun as far back as humans have existed on this planet. For thousands of years, people have "worshipped" the sun. Ra, the sun god, was considered the first king of Egypt.  In Greece there were two sun gods, Apollo and Helios. The influence of the sun also appears in many other religions.

 

We know today, that the sun is our nearest star. Without it, life would not exist on our planet. We use the sun's energy every day in many different ways.  When we hang laundry outside to dry in the sun, we are using the sun's heat to do work; it’s helping us to dry our clothes.  The sun is a very important part of the Circle of Life.  Plants use the sun's light to make food. Animals eat plants for food. Decaying plants hundreds of millions of years ago produced the coal, oil and natural gas that we use today.  Indirectly, the sun or other stars are responsible for all of our energy. Even nuclear energy comes from a star because the uranium atoms used in nuclear energy were created in the fury of a nova - a star exploding.

       

One of the things we use the sun for is for energy

 

Another form of solar power plants to make electricity is called a Central Tower Power Plant.  Sunlight is reflected off 1,800 mirrors circling a tall tower. The mirrors are called heliostats and move and turn to face the sun all day long.  The light is reflected back to the top of the tower in the center of the circle where a fluid is turned very hot by the sun's rays. That fluid can be used to boil water to make steam to turn a turbine and a generator.  Scientists say that some of the larger central tower power plants can make electricity for 100,000 to 200,000 homes.

 

Pros:

One of the advantages of solar energy is that it is clean, and it’s free.  It is also renewable, so it can provide us with energy for a long, long, time.

 

Cons:

The sun doesn’t shine at night.  So, we would not be able to produce energy from the sun at night.  On cloudy days, the sun’s rays might produce little energy, and in places like Alaska, they would have little energy during the winter when the sun stays down.