Solar energy facts for kids

Near the equator, the Sun gives about 1000 watts of energy per square meter to Earth's surface.

The top picture shows how sunlight is weaker near the Earth's poles. The bottom map shows how much solar energy reaches Earth after clouds and dust block some of it.

This map shows how much solar energy Europe gets.

Solar energy is power that comes from the Sun. People have used it for thousands of years in many ways. The oldest uses of solar energy were for heating, cooking, and drying things. Today, it is also used to make electricity. This is very helpful in places far from cities or in outer space, where other power sources are not available.

Making electricity from solar energy is becoming cheaper. Because the Sun always provides energy, solar power is a renewable energy source. This means it will not run out, unlike coal and oil.

How We Use Solar Energy

Solar energy is used in many ways today:

• To make hot water and heat buildings.
• For cooking food.
• To create electricity using solar cells or special engines.
• To remove salt from seawater.
• To dry clothes and towels in the sun.
• Plants use it for photosynthesis, which helps them grow.
• In special solar cookers for cooking food.

Sunlight's Power

Solar panels on a sound barrier near the Munich airport absorb solar energy.

After sunlight travels through Earth's atmosphere, most of its energy is in the form of visible light and infrared light (heat). Plants use sunlight to make their own food through a process called photosynthesis. Humans use this stored energy when they burn wood or fossil fuels. We also get this energy by eating plants and animals.

Solar radiation reaches Earth's upper atmosphere with a power of 1366 watts for every square meter. Because Earth is round, areas closer to the poles are angled away from the Sun. This means they get much less solar energy than areas closer to the equator.

Today, solar cell panels can turn about 15% of the sunlight that hits them into electricity. Imagine if we covered a small part of the Earth with efficient solar panels. This area could produce enough electricity for the whole world's needs!

Solar Technologies

Many technologies have been created to use the Sun's energy. Some of these use solar energy directly for light or heat. Others turn sunlight into electricity.

Solar Power Plants

Solar power plants change sunlight into electricity. They do this in two main ways:

• Photovoltaics (PV): These use solar cells to turn light directly into electric current.
• Concentrated Solar Power (CSP): These systems use special lenses or mirrors. They focus a large area of sunlight into a small, powerful beam. This beam then creates heat to make electricity.

A view of the Ivanpah Solar Electric Generating System in California. The Clark Mountain Range is in the distance.

Solar Cookers

Cooking with a solar cooker.

Solar cooking uses the Sun's energy instead of fuels like charcoal or gas. Solar cookers are cheap and good for the environment. They are becoming popular in places where wood is scarce or fuel is expensive. They also help prevent fires. Solar cookers often have a glass cover. They use mirrors to focus the Sun's rays, which makes them get hotter.

Solar Heaters

A house in the Czech Republic with solar panels for heating.

The Sun can be used to heat water instead of using electricity or gas. There are two main types of solar heating systems:

• Liquid-based systems: These heat water or a special liquid in a "hydronic" collector.
• Air-based systems: These heat air in an "air collector."

Both types can help heat buildings that use forced air systems.

Solar Cells

A 4-inch by 4-inch solar cell.

Solar cells are devices that turn light energy into electrical energy. Sometimes, "solar cell" means a device that specifically uses sunlight. "Photovoltaic cell" is a broader term for any cell that turns light into electricity.

Solar cells are used in many places. They are great for situations where there is no regular power from the grid. This includes remote areas, Earth-orbiting satellites, and space probes. You can also find them in small items like calculators and wrist watches. Many solar cells are put together to form a solar panel. These panels can make enough electricity for practical use. The electricity from solar panels can be stored in special rechargeable batteries for later use.

Related pages

• List of renewable energy topics

Images for kids

• 

  The source of solar power: the Sun

• 

  Solar water heaters facing the Sun to get the most energy.

• 

  MIT's Solar House #1, built in 1939, used stored heat for year-round heating.

• 

  This large dish in Auroville, India, uses the Sun to make steam for cooking.

• 

  Solar water disinfection helps clean water in Indonesia.

• 

  Darmstadt University of Technology, Germany, won a competition in 2007 with this energy-efficient house.

• 

  Greenhouses like these in the Netherlands grow vegetables, fruits, and flowers.

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  Special concentrated solar panels are getting more powerful.

• 

  Thermal energy storage. The Andasol plant stores solar energy in tanks of molten salt.

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  This shows how the cost of solar panels has changed over time.

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  In 2016, Solar Impulse 2 was the first solar-powered aircraft to fly around the world.

See also

In Spanish: Energía solar para niños