The Mysteries of Life

Name:______Period: ______Folder: ______

Dear Tim and Moby,

Where do we get the power to heat our homes, light up street lamps, and move cars?

Abby (New York)

Humans use energy for everything! As a result, we’ve come up with a lot of ways to generate it. Probably the most basic method of energy production is from burning biomass, like wood and animal droppings. This campfire my dad built is a good example of biomass energy. Biomass energy is used all over the world for cooking, lighting, and heating.

Now, if you’re talking about electricity, there are lots of ways to generate that. Most involve a device called a generator. Generators come in tons of shapes and sizes, but essentially, they all do the same thing: convert motion into electricity.

Note From Here’s the basic principle: if you rotate a coil Mrs. Stevens: between the poles of a magnet, an electric current This is flows through the coil as it passes through the important!! magnetic field.

--Beep? Good question.

Finding the energy to turn the coils is the real trick. Here are some ways to do it.

Water powered, or hydroelectric, power units use water trapped by reservoirs and dams to generate energy. Water flowing through a small opening in a dam can turn a wheel called a turbine, which is attached to the generator. This can also be accomplished by using the ocean’s tides. At high tide, water is trapped in a reservoir. At low tide, the water is released, turning turbines. Note From Mrs. Stevens: More on this tomorrow!

Windmills work in a way similar to hydroelectric plants, using energy provided by the wind. Both wind and water energy are often used to create mechanical energy, turning gears to pump oil or water out of the ground, or to grind stuff up, or anything, really.

Note From Mrs. Stevens: More on this on Tuesday! Note from Mrs. Stevens: Geothermal Energy is not a focus point for us this year

Geothermal energy comes from hot rocks in the earth’s crust that hold temperatures up to 1,000 degrees Celsius. Water heated by these rocks turns to steam, which turns the turbines of generators.

Solar energy comes from the sun. Heat from the sun can be focused onto water, creating steam, which turns the turbine of a generator. Solar energy can also be converted directly into electricity with the use of a photovoltaic cell.

Note From Mrs. Stevens: Solar energy is not a focus point for us this year

Nuclear reactors take advantage of the unstable atoms in substances like uranium and plutonium. A process called nuclear fission splits the nuclei of these atoms, creating a controlled chain reaction and generating a lot of heat.

--Beep! You guessed it! The heat turns water into steam, which turns the turbines of generators.

Note From Mrs. Stevens: We will look at Nuclear energy later this unit! Then we have fossil fuels. As their name suggests, fossil fuels like coal, oil and natural gas, come from the remains of dead animal and plant matter.

Fossil fuels are burned, turning water into steam, turning turbines.

Note From Mrs. Stevens: This is very, VERY Important!!

A couple of problems with fossil fuels: First, burning them produces a lot of pollution, as well as carbon dioxide, which contributes to global warming. Second, the process that turns a tree into a fossil fuel takes millions of years, much longer than it takes us to burn it. At our present rate of consumption, it’s not a question of whether we’ll run out of fossil fuels, it’s just a matter of when. Some say it could happen in the next few centuries. That’s why scientists and industries are working hard to develop alternate energy sources, like fuel cells for example. Fuel cells convert hydrogen and oxygen into water, producing electricity in the process. The only by-products of the reaction are heat and water. The kinks are still being worked out, but hopefully, alternative energy sources will bring us closer to safe, clean energy sources that humans need so badly.

Now you’ve done it. --Beep. Dad, the fire, uh, went out! Hey, pass me a marshmallow? I meant a fresh one! I

LABEL: Label the following generator diagram image from the movie: A. Circuit Wires B. Copper Coil C. Load (uses the electricity) D. Magnet E. Magnetic Field F. Turbine

MAGNET

MAGNETIC FIELD

COPPER COIL

TURBINE

LOAD (uses electricity)

CIRCUIT WIRES 6. This is the water flow ______5. The ______acts like hot, wet wind that turns a ______4. The heat is 7. Items that use used to electricity are called ______a "______" on the water, circuit. water flow creating ______8. When the turbine spins, it runs the generator, creating an e______c______that 3. Burning the fuel creates ______the load uses.

1. We need a F______S______2. The fuel is burned in an ______3 examples: (a special oven)