Lean About Solar Energy

About the Sun

The sun is the biggest, brightest, and hottest source of light available to us on the earth. It is in the center of our solar system and all the other planets, including Earth, spin around it. Read our newsletter about the solar system to learn more.

Did you know that the sun is actually a star? The outside of the sun (its surface) is covered with very hot gases. The different gases mix together and cause reactions that are called nuclear reactions. Nuclear reactions create a lot of energy, which makes the sun very hot. The heat creates a lot of light too. Did you know that the sun is so bright that it will damage your eyes if you look directly at it? The light from the sun can also hurt your skin. Have you ever had a sunburn? Although sun rays can hurt our bodies if we aren't careful, nothing would be able to live on the earth without the energy we get from the sun in the forms of heat and light. Plants use energy from the sun to make food, then animals and humans eat plants for food. Without the sun, Earth would be too cold for anyone or anything to live.

The sun is 93 million miles away from Earth. If it were possible to drive from here to there, it would take over 150 years driving at 70 miles per hour (about the same speed you would travel on a highway)! However, light travels very fast and can get from the sun to the earth in about 8 minutes! Here is a close-up picture of the Sun from NASA.

What Is Solar Energy?

Solar energy is light and heat that comes from the sun. Solar means sun and energy is what we need in order to do things. We use energy to do things like eat breakfast and play outside. Energy is also in things around us, like light and heat. The sun shines in the day, giving us light. It also makes the earth warmer, giving us heat. You can learn more about energy here. Solar energy is known as renewable energy, which means that it can never run out.

The rays of light and beams of heat from the sun contain energy that can be changed into electricity through a device called a solar cell or solar panel. Solar cells are made of a material that absorbs energy from the sun. Once it is inside of the cell, the energy breaks up into electrons and protons. Electrons have a negative charge and protons have a positive charge. All the negative charges are attracted to one side of the solar cell and the positive charges are attracted to the other side. When the solar cell is connected through wires to a light bulb or other object, it works like a battery and electrons flow through the wire and bringing electrical energy to a light bulb that makes it light up.

What Can Solar Energy Be Used For?

Solar energy can be used for a lot of things. Electricity from solar panels can be used to make things work, like traffic lights and lights in a home or outdoors. It can also heat water in a home, run air conditioners, radios, flashlights, and chargers for electronics like cell phones or cameras, and more. The sun's heat energy can be used for lots of things too, even without solar panels! It can be used to cook food using a solar cooker, like this oven made from a pizza box! The sun's light can be used during the day. For example you can open the blinds and curtains on windows to let natural light come inside instead of turning on lights. That way your family will also save money by not using as much electricity. Can you think of other ways you can use sun's energy to do things?  Here are some ideas:

- Inside a greenhouse to keep the temperature warm enough for plants to grow all year, even in the winter! (Think about this: on a hot summer day, when a car is parked in the sun for awhile, the inside of the car gets very hot because the car absorbs heat from the sun and everything warms up. That is the same way a greenhouse works.)
- To dry clothes on a clothesline.
- To warm up water to give a dog a bath outside.
- To heat up the water in a swimming pool.
- You can even use the sun's heat to make salt water drinkable! This project shows you how.

Here are some good things about solar power:

• It can never be used up. This means that it is renewable energy.
• After a solar panel is paid for, solar energy is free!
• It can be used in places where electricity is not available, like far away from cities, up in mountains, or even on boats in the ocean!
• It does not release anything into the air. Some kinds of energy release things that are harmful to the environment, people, and animals.
• Solar panels last a long time, usually about 30-40 years!

These are some problems with solar power:

• Solar panels cost a lot. They are expensive to make and keep because they are made of glass and fragile minerals that can break easily, costing money to fix.
• It is only available when the sun is around - that means it won't work when it's cloudy or at nighttime!
• It takes lots of space to hold the large solar panels that are needed to make enough electricity to keep large things, like your house, running smoothly.

Science Words

Reflection - when light or heat hits an object and bounces back in the opposite direction.

Absorption - when light or heat is collected or soaked up by an object.

Nuclear reactions - reactions that take place between hot gases on the sun. These reactions release energy.

Solar energy - light and heat that comes from the sun and can be used to do work.

Renewable energy - a source of energy that can never be used up or run out. Energy that comes from the sun, water, or wind are examples.

Printable Worksheet & PDF

Print out this page on a sheet of heavy paper or cardstock. Kids can color the pictures and cut out the squares to make a matching game. Half of the squares show a way to use solar energy as an alternative to the picture shown on the other squares. Place all the squares face down and take turns flipping two over per turn to find the ones that go together. Talk about ways to save energy from other sources by using the sun's power.

To view a printable version of this newsletter and the worksheet together, click here.

Website artwork, text and images Copyright © 2010 Home Training Tools, Ltd. All rights reserved.