Originally appears in the Summer 2011 issue

How can teachers and environmental educators broach the overarching issue of global climate change in such a way that students are empowered to do something about it, rather than becoming despondent? What are the basic understandings that young people need in order to generate their own renewable energy and cut down on greenhouse gases?

Every day, the solution shines down upon us and blows in on the wind. Understanding how the immensely powerful forces of nature work, and knowing how to use them for generating renewable energy, are keys for unlocking young minds and energizing youth toward action. I developed the Kids’ Power Program so that youth can have fun while generating and storing renewable energy that they can use in everyday life.

This subject is a natural entry point for getting kids excited about physical forces and electricity. After presenting my program to classes of 6th graders in Connecticut recently, the students started coming into class eager to power up using their own original inventions for mini-wind turbines.

It’s all about the Power of One: Every single environmental action taken by every single person adds up to have a powerful positive impact on the world. If all of the approximately 120 million households found in Canada and the United States lit just a single lightbulb with solar-powered electricity, instead of with electricity supplied by the power grid, it would save enough energy to power all of the lighting for 4 million households. This would also cut down on greenhouse gas emissions and shrink our carbon footprints.

The following article is adapted from my new book, Catch the Wind, Harness the Sun: 22 Super-Charged Science Projects for Kids (Storey Publishing). This excerpt shows that critical science concepts can be written and presented so that they are understandable, compelling, fun and useful tools for Earth stewardship. In essence: Earth is powered by a star, the Sun, whose energy comes from nuclear fusion. Solar power is a nearly boundless source of renewable energy that we can harness for heat and light, to generate electricity and to help fight global warming.

 

The Sun is Our Home Star

The Sun is our home star.  This great ball of heat and light, this round mass of fire, was called Sol in ancient Rome and Helios in Greece. According to a legend from the Muskogee (Creek) peoples of the southeastern United States, the Sun was carried aloft on top of a vulture’s head, inside a silken bag woven by Grandmother Spider. On bright, sunny days, when the light is just right, you can still see gossamer rays of Grandmother Spider’s bag shining down.

Even though the Sun is more than 93 million miles (150 million km) away, we can feel its heat and light as though it were close by. Just how far away is the Sun? If there was a road that led from Earth to the Sun, your family could climb into the car and drive there. But get out your iPods and earbuds, then download a ton of songs, because a ride to the Sun is going to take awhile.

Let’s say that, on the road to the Sun, the driver brought the car up to 70 miles per hour (113 kph) and set it on cruise control for the whole ride, 24/7. At that speed, if no one stopped to get a bite of food or to take a bathroom break and the drivers rotated so that you never had to slow down or stop, you would arrive at the Sun in 152 years! How long is that? If your family had begun such a journey back in 1861 — the first year of the U.S. Civil War — you would finally reach your destination in 2013.

Even from that great distance, it takes the Sun’s energy only 8 minutes and 20 seconds to reach us on Earth while traveling at the speed of light — around 670,000,000 miles (1,078,231,000 km) per hour. Traveling at that speed, sunlight would get a hefty speeding ticket on the interplanetary highway, if only someone could catch it!

How big is the Sun? It would take 109 Earths, placed edge to edge, to reach across the face of the Sun. And if you had a bag as large as the Sun, you could fit 1 million Earths inside.

A Real Ball of Fire

At times, when a person is being very active, someone will say, “You’re a regular ball of fire.” But no one can hold a candle to the Sun. At its center or core, the Sun’s temperature is 28 million°F (15.6 million°C). At this great heat the atoms of hydrogen join together to form helium, also from the Greek, Helios. Energy is created every time hydrogen joins to form helium. This reaction, called nuclear fusion, drives the Sun’s energy. Even though 600 million tons (544,311,000 metric tons) of hydrogen change into helium every second, there is still enough hydrogen left for the Sun to last another 5 to 6 billion years.

When we catch a brief glimpse of the Sun, we see the 200-mile- (322 km) thick layer called the photosphere, which is about 10,000°F (5,500°C). Sunspots are about 2,700°F (1,500°C) cooler than the rest of the photosphere, so they appear darker. Some sunspots are wider than the diameter of Earth. They can last for anywhere from a few hours to a couple of months, and they can produce violent explosions called solar flares. A large solar flare can last for a few hours, interrupt satellite communications on Earth, and generate enough energy to power the entire United States for 100,000 years. Sunspot activity runs in cycles of about 11 years. A high point in the number of sunspots is expected from late 2011 through 2013.

Surrounding the photosphere is another, somewhat hotter layer of the Sun called the chromosphere, which is 1,000 to 2,000 miles (1,600 to 3,200 km) thick.

Finally, like a shimmering halo, comes the corona, in which the temperature shoots up to more than 1 million°F (555,500°C). Superheated gases from the corona rocket off into space as charged particles called the solar wind. We can only see the reddish chromosphere and the corona’s whitish streamers during a total solar eclipse, a time when the moon passes directly between the Sun and Earth and the Sun is completely blocked out wherever the moon’s shadow falls. But the Sun’s energy can damage eyes and cause blindness, so don’t ever look directly at the Sun, even during an eclipse.

Neon in the Sky

In the Northern Hemisphere, especially when sunspot activity is high, look for spectacular, shimmering displays of the northern lights, Aurora Borealis. In the Southern Hemisphere, catch the southern lights, Aurora Australis.

These dramatic nighttime spectacles are created when the solar wind sends charged electrons and protons racing toward Earth, where they slide along Earth’s magnetic field toward the North and South poles. There the solar particles crash into the molecules of Earth’s atmospheric gases, causing those electrons to jump out of their orbits. The energy given off by the excited electrons shows up as brightly colored curtains and ribbons of light — green, red, pink, white, and lavender.

We’ve all experienced or seen in books the brightly colored neon lights that spell out the names of city restaurants and markets. The process that creates the northern and southern lights is similar to the way a neon light works: electricity passes through glass tubes filled with gas and causes it to glow. Each gas emits a different kind of color when it glows, such as neon (reddish orange), mercury (bright blue), argon (lavender), krypton (silver white), xenon (pale blue) and helium (gold).

A ReNEWable Day

Oil, coal, and natural gas, also called fossil fuels, were formed from the remains of prehistoric plants fed by sunlight, plus the animals that ate those plants. That means fossil fuel is solar power stored underground from sunlight that shone long ago. These kinds of energy took millions of years to form, and it will take another few million years to make more. So when we rely on fossil fuels to heat our houses and run our cars, we are counting on types of energy that will one day run out. Once fossil fuels are all taken out of the ground, there won’t be any more for millions of years.

The Sun, however, shines every day, so its energy won’t run out. Even on cloudy days when the Sun doesn’t “come out,” our home star is up there wrapping Earth in its powerful blanket of energy. That’s why solar energy is called renewable — it sustains itself constantly, which means it will give us life and won’t run out for at least another 5 billion years. Every single hour, enough of the Sun’s energy reaches Earth to supply all humankind’s energy needs for an entire year.

Even though the Sun has so much positive potential, we use solar energy for only a tiny amount of our energy supply. Just 7 percent of our energy comes from all renewable sources put together, including solar, wind, hydroelectric, tidal, geothermal, and biomass power. But only 1 percent of this 7 percent comes from solar power! That means less than 1/10 of 1 percent of our total energy supply comes from the Sun. That’s a tiny amount!

The Sun doesn’t care where it falls or on whom its rays shine. The Sun reaches all places — high and low; wet and dry; tropical, temperate, and covered with snow and ice. Despite this abundance of sunshine, there are about two billion people in the world who still don’t have electricity. It would cost less to power these households with solar energy than it would to create new power plants and power lines. There is a lot of potential for solar power. How can you help?

Capture the Sun

Like a wild bronco, the Sun’s energy is all over the place. But we can tame that energy and put it to work. There are several ways to do this.

Passive Solar

Simply catching the rays heat of the Sun is called passive solar. Passive solar is used in three ways: (1) to heat a house or other space; (2) to heat water; and (3) to bring light into dark spaces.

Passive Solar Heat. To heat spaces or water with passive solar, all you need is a sunny window or something dark to absorb solar heat. The darker the color, the more of the Sun’s energy it absorbs. Spaces can be solar-heated by building them with large, south-facing insulated windows for catching and holding the heat. If the walls and floors are a dark color where the sun strikes, they will absorb solar heat during the day and radiate that same heat into the house at night. Some people keep large, often dark-colored containers of water in the sunlight. Once water heats up, it radiates that heat for a long time.

Many solar water heaters consist of dark tubes that are enclosed in a glass-covered flat box, or panel, and exposed to the Sun. Fluid that runs through tubes is used to heat water. In some systems, the water is heated directly by the sun. These solar collectors can be placed on a roof or on a raised platform in a sunny place on the ground. There are a lot of solar water heaters already being used in North America, including those that are designed for heating pools.

Passive Solar Light. Some houses have interior rooms with no windows or dark rooms with small windows. Many times, with good planning, small daylight shafts, such as the Solatube, can be made to catch and direct light from a brightly lit part of a roof or wall down into the dark room. These shafts are either painted white or lined with a shiny metal surface to reflect the light down.

Sun-tricity

With the right kid of equipment, it’s possible to use sunlight to generate electricity.

Photovoltaic, which means “electricity from light,” comes from the Greek word for light (phot-) and the name of the Italian inventor, Alessandro Volta, who created the first battery.

Picture tiny electrons moving around the nucleus of an atom. When the Sun’s energy strikes a photovoltaic solar panel, which is usually made from an element called silicon, the electrons become energized. They escape their atomic bonds and can only move from bottom to top through the photovoltaic (PV) cell’s two thin layers of silicon. (The lower section, which has too few electrons, is called the positive ‘p-type layer, and the upper is the negative ‘n-type layer.) Opposing charges on the top and bottom cause electrons to flow through the circuit of wires attached to the PV cell to form a current.

The electrons moving along the wire from the PV cell form direct current, or DC. This current can be used to power things that run on electricity, or it can be stored in batteries for use later on. If someone wants to feed this power into a household electrical system, it is usually run through an inverter, which changes the DC current to alternating current or AC — which is what our household appliances are designed for.

Less than 1/2 of 1 percent of all the electricity that is generated in the world is made using photovoltaic panels. Isn’t it high time that we put more of the Sun’s colossal power to work?

 

Activities

Sun Burns

If you ever wanted proof of the power of the Sun, these next two activities are for you. By gathering the Sun’s energy that falls over a just a few inches of Earth’s surface and focusing it with a magnifying glass, you can create a point of light-heat that is hot enough to light a fire with paper and even burn wood. The temperature at which something will burn is called the flash point. The flash point for paper is 451°F (233°C) and for wood is 572°F (300°C).

Activity: Writing with Sunlight

When writing with sunlight, you’ll see how quickly the sun’s energy burns a piece of wood, and use it to create a nameplate or sign. Then you can ponder how else to put the Sun’s energy to use.

!Safety First!

  • Do this activity only with adult supervision.
  • Wear safety glasses and work carefully when sawing wood. When using the magnifying glass, don’t point the light anywhere but at the exact spot where you need to focus it for your activity. The magnifying glass focuses the Sun’s powerful radiation to a tiny point that is extremely hot and bright. Use that point of sunlight with the same safety measures you would use when handling a lighted match.
  • Wear sunscreen that blocks UVA and UVB rays (SPF 30 minimum).
  • Wear sunglasses when looking at the focused point of sunlight. Use sunglasses that protect your eyes from 100 percent of the Sun’s harmful ultraviolet rays, including UVA and UVB. Just to be safe, work on your Writing with Sunlight project for only short periods of 10 to 15 minutes per day, to give your eyes a long rest from looking at the bright light. If you do not wear sunglasses while doing this activity, or even while looking over the shoulder of someone else doing it, you can burn your eyes’ retinas.

Materials:

  • UVA and UVB sunscreen (SPF 30 minimum)
  • Flat piece of softwood such as white pine (a piece that is 1/2 inch [1.25 cm] thick by 4 inches [10 cm] wide will do); be sure it’s long enough to fit the lettering you plan to use.
  • Safety goggles
  • Small handsaw
  • Sandpaper (medium grit, #80)
  • Pencil
  • Sunglasses (100% UVA & UVB protective)
  • Handheld magnifying glass
  • Eraser

Do the Deed

All you need is a little patience and a steady hand to write with sunlight. Keep the point of the beam as small as possible, and use it like a hot pencil.

  1. Decide what you want the sign to say. Perhaps you want to make a sign with your name or the name of a friend, a family member, or a pet. You could create a sign to hang on the door of your room. Or how about making a sign that says “Catch the Wind” or “Harness the Sun”?
  2. Gather a piece of wood on which you want to make the sign. Any kind of wood will work, but softwoods, like white pine, are lightweight and easy to cut, sand, and burn. If you don’t have a piece lying around the workshop in your house, try going to a hardware store or lumberyard and asking if they have a short piece of scrap wood that they’ll sell or give to you.
  3. Put on your safety glasses, and use the saw to cut the wood into the size and shape you want, being certain to allow enough room for some lettering. A single name would easily fit onto a piece that’s about 12 inches (30 cm) long.
  1. Sand the edges smooth so that the sign will look finished and you won’t get splinters when handling the wood. Just rub the sandpaper over any rough edges until smooth.
  1. Lightly write the lettering onto the sign in pencil, along with any simple designs that you want to go with it. Use simple block letters that are only a few inches high, and space them as you normally would when writing on paper.
  1. Take the board outside on the next sunny day. Put sunglasses on to protect your eyes from the bright light. (See the !Safety First! message about sunglasses at the beginning of this activity.)
  2. Use the magnifying glass to focus the sunbeam onto the first letter of your sign until it starts to smoke and turn black.
  1. Gradually move the beam along the lines of the lettering and designs, allowing the light to linger just long enough to create a black line where the Sun is burning into the wood. You are writing with sunlight!
  1. Erase any leftover pencil marks.

Follow the Lead

  • Can you think of any other small-scale tasks you could do or things you could make by focusing sunlight in this way?
  • What other safe, useful things could you do by focusing the Sun’s energy with a magnifying glass?
  • Now, think big. How could the Sun’s energy be focused on a larger scale to create electricity? Keep in mind that enough heat would have to be gathered to boil water and turn the blades of a turbine that is connected to an electrical generator. Draw a diagram of how you could accomplish this by designing a solar electrical generator.
  • Once you’ve drawn your design, go online and search under “solar power plant” to see if the designs of real power stations are anything like the one that you imagined.

 

Activity: Solar Heat by the Gallon

Water is the best common substance to use for storing heat. It takes a lot of heat to warm up water, but it loses that heat very slowly. A container of water that heats up in the sunlight continues to give off that heat well into the night. Follow the steps in this activity to create a small passive capture solar heater for your school or home. 

Materials:

  • Dish soap
  • Dish drainer
  • Four (or more) 2-liter-size beverage bottles with screw-on lids
  • Drop cloth
  • Paintbrush
  • Can of flat black interior latex paint (any flat, dark color will do)
  • Clean, quart-size (about a liter) can or plastic container full of water for cleaning the paintbrush
  • Water for filling bottles
  • Bookshelf

Do the Deed

Passive solar heat is easy to catch. All you need is something dark that absorbs the Sun’s heat during the day and then radiates it back into the room at night.

  1. Use the dish soap to thoroughly clean at least four 2-liter plastic beverage containers. Save the caps. Remove labels from the outside of the containers, and wash the outside well so the surface is clean and paint will stick to it. Rinse the inside of each container well, and put it upside down in the dish drain to dry.
  2. Once the beverage containers are dry, place them on the drop cloth and use the brush to paint them with the flat black paint. It is best to do this outside or in an open garage or other space that is well ventilated.
  3. Use the container of water for cleaning the paintbrush, then set the brush aside to dry.
  4. Once the paint is dry, fill each container with water and cap it off snugly. Leave about an inch of air on top to allow space for the water to expand as it warms up. Be sure not to crush or bend the containers while handling them or the paint might crack off.
  5. Place the black jugs full of water on the top of a bookshelf in a sunny window or on a windowsill to create a simple solar heat collector.

Follow the Lead

  • Add more shelves and “Solar Heat by the Gallon” jugs to your homemade heat collector to increase its storage capacity.
  • Experiment by placing other kinds of dark-colored containers full of water in the Sun to see which one holds the heat longest once the Sun goes down. Try using containers made from glass, ceramic, metal, or thicker plastic. Which kind of container works best? Why?
  • On a sunny day: Open one of the bottles in the morning, and lower inside it the long, thin sensor end of a cooking thermometer or a science-class dial thermometer. If the bottle is deeper than the thermometer is long, you may need to tie a string around the top of the thermometer. Make a graph showing temperature along the left-hand side and time along the bottom. Read the thermometer every half hour, capping the container after each reading. Use a dot to record the temperature at each half-hour time mark. Once the Sun goes down, observe how the temperature rose and fell during the day. When was the “heat of the day?” Was it exactly in the middle of the day? Why, or why not?
  • Try this same experiment by recording and graphing the water temperature on a cloudy day. How does that temperature pattern compare with the results from the sunny day?
  • Repeat the previous experiment using two bottles: one that sits in direct sunlight, and one that rests in the shade. Using a different colored marker for each bottle, chart the temperature of both bottles on your graph throughout the day. Compare the temperature changes that occurred in each bottle. Why do you think you got that result? Is it what you expected?
  • How does the temperature chart from the bottle that sat in the shade in this experiment compare with the graph you made earlier of the bottle kept exposed to the sky on a cloudy day?

To view the photo-rich magazine version, click here.

 

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Michael J. Caduto is an environmental educator, ecologist and the co-author of the landmark Keepers of the Earth® series. Apart from Catch the Wind, his recent other book is Riparia’s River (Tilbury House). Learn more about his programs at www.p-e-a-c-e.net.