Sun

= Sun Energy (Solar Power) = toc

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What is it?
media type="file" key="s1.mp3" width="240" height="20" The big ball of fire in the sky that we call the sun is probably the most important **renewable resource** on Earth. We know that the sun will keep on burning for a very long time. It’s a good thing, because plants get their energy from the sun’s rays, and we get our energy from eating those plants! We also know that the sun produces heat and that heat is a kind of energy. But did you know that scientists can actually capture the sun’s energy and use it to heat your home or power your lights?

How does it work?
media type="file" key="s2.mp3" width="240" height="20" We use solar energy in two ways. When we convert the sun’s energy into electricity, it is called **photovoltaic energy**. This is done using a special kind of technology called a **photovoltaic cell**. Basically, when sunlight hits the photovoltaic cell, it produces a current of electricity.

When we use the sun’s energy for heat, it is called **thermal energy**. If you’ve ever climbed into a hot car on a sunny summer day, you probably already know about thermal energy – when the sun shines, the temperature goes up! When we need a lot of heat, though, we need to be able to capture more of the sun’s energy. That’s where solar power plants (like the one in the picture on the left) come in. At a solar power plant, lots of reflectors are used to reflect the sun’s rays to one spot. Then all of that sunlight can be captured and turned into heat.

== How is it used today? == media type="file" key="s3.mp3" width="240" height="20" Solar energy can be used to power a lot of different things. Solar energy can heat our homes and buildings. Solar energy can also be used for electricity or to heat our water. It is even used to heat swimming pools and power some calculators and cars!

Some buildings are built with solar panels on the roof. Other buildings, like this library in Manchester, England, have photovoltaic cells built into the windows. The North City Library (right) gets 50% of its electricity from solar energy!

What are the advantages?
media type="file" key="s4.mp3" width="240" height="20" Solar energy is clean and renewable, so it does not hurt the environment and won’t run out any time soon! If we start using more solar energy, we will not have to depend on fossil fuels as much. Also, if you have the equipment that is needed to produce solar energy, you don’t have to do anything but wait for the sun to shine! The sun produces SO MUCH energy that it could be enough to solve all of our energy problems!

What are the disadvantages?
media type="file" key="s5.mp3" width="240" height="20" Solar power is expensive compared to other forms of energy. This is because it costs a lot of money to build the equipment needed for solar energy. It also depends on the weather – if the sun isn’t shining, there is no way to get more power! This means that most people still need to have a back-up plan if they want to use solar energy.

Is there a solution for using solar power in the future?
media type="file" key="s6.mp3" width="240" height="20" What do you think? Should we use solar power more or less than we do now? What will we need to do to make your solution work?

Bibliography

©2008 E. Crispino