Energy is like the secret ingredient that makes everything work. It heats our homes, keeps our food cold, and lights up our rooms. It’s not just in our houses, though. Schools where we learn, offices where people work, and big buildings where things are made all need energy, too.
Have you ever watched cars and buses zooming down the street? Or maybe you’ve seen big airplanes flying across the sky and trains chugging along tracks. They’re all powered by energy. But it’s not just these big things that need energy. Fun stuff like music from your speakers, playing with your pet dog, or even the energy we use to move and play sports – it’s all because of energy.
Even tiny things that we can barely see, like bugs buzzing around, need energy. And so do big things we can’t live without, like the internet that connects us all, and the farms that grow our food. Even the way water moves around the planet and changes the weather, it’s all about energy.
To really get what’s going on in the world, we need to understand energy. That’s why we’re going to dive into what energy is, how it works, and why it’s so important for everything.
Energy Merit Badge Requirements
| 1. Do the following: (a) With your parent’s permission, use the internet to find a blog, podcast, website, or an article on the use or conservation of energy. Discuss with your counselor what details in the article were interesting to you, the questions it raises, and what ideas it addresses that you do not understand. (b) After you have completed requirements 2 through 8, revisit your source for requirement 1a. Explain to your counselor what you have learned in completing the requirements that helps you better understand the article. |
| 2. Show you understand energy forms and conversions by doing the following: (a) Explain how THREE of the following devices use energy, and explain their energy conversions: toaster, greenhouse, lightbulb, bow drill, cell phone, nuclear reactor, sweat lodge. (b) Construct a system that makes at least two energy conversions and explain this to your counselor. |
| 3. Show you understand energy efficiency by explaining to your counselor a common example of a situation where energy moves through a system to produce a useful result. Do the following: (a) Identify the parts of the system that are affected by the energy movement. (b) Name the system’s primary source of energy. (c) Identify the useful outcomes of the system. (d) Identify the energy losses of the system. |
| 4. Conduct an energy audit of your home. Keep a 14 day log that records what you and your family did to reduce energy use. Include the following in your report and, after the 14-day period, discuss what you have learned with your counselor. (a) List the types of energy used in your home such as electricity, wood, oil, liquid petroleum, and natural gas, and tell how each is delivered and measured, and the current cost; OR record the transportation fuel used, miles driven, miles per gallon, and trips using your family car or another vehicle. (b) Describe ways you and your family can use energy resources more wisely. In preparing your discussion, consider the energy required for the things you do and use on a daily basis (cooking, showering, using lights, driving, watching TV, using the computer). Explain what is meant by sustainable energy sources. Explain how you can change your energy use through reuse and recycling. |
| 5. In a notebook, identify and describe five examples of energy waste in your school or community. Suggest in each case possible ways to reduce this waste. Describe the idea of trade-offs in energy use. In your response, do the following: (a) Explain how the changes you suggest would lower costs, reduce pollution, or otherwise improve your community. (b) Explain what changes to routines, habits, or convenience are necessary to reduce energy waste. Tell why people might resist the changes you suggest. |
| 6. Prepare pie charts showing the following information, and explain to your counselor the important ideas each chart reveals. Tell where you got your information. Explain how cost affects the use of a nonrenewable energy resource and makes alternatives practical. (a) The energy resources that supply the United States with most of its energy. (b) The share of energy resources used by the United States that comes from other countries. (c) The proportion of energy resources used by homes, businesses, industry, and transportation. (d) The fuels used to generate America’s electricity. (e) The world’s known and estimated primary energy resource reserves. |
| 7. Tell what is being done to make FIVE of the following energy systems produce more usable energy. In your explanation, describe the technology, cost, environmental impacts, and safety concerns. – Biomass digesters or waste-to-energy plants – Cogeneration plants – Fossil fuel power plants – Fuel cells – Geothermal power plants – Nuclear power plants – Solar power systems – Tidal energy, wave energy, or ocean thermal energy conversion devices – Wind turbines |
| 8. Find out what opportunities are available for a career in energy. Choose one position that interests you and describe the education and training required. |
1. (a) The Impact of Energy Conservation on Our Planet and Wallet
Understanding how we use energy and finding ways to save it can have a big impact. By using less energy, we help the environment by reducing harmful gases from burning fuels like coal or oil. This can slow down global warming, which is when Earth gets too hot and starts having problems like floods and really strong storms.
Saving energy also means we use less of the fuels that can run out, like oil and natural gas, giving us more time to find new kinds of energy that won’t run out, like wind or solar power.
Plus, using less energy can save us money because our bills for things like electricity and water will be less, and we might get special savings from the government for being good at saving energy .
| Benefits of Energy Conservation | How It Works | Possible Savings |
|---|---|---|
| Slows down global warming | Reduces greenhouse gas emissions | Protects cities and nature |
| Protects animal homes and water | Uses less non-renewable energy | Less money spent on bills |
| Improves air and health | Makes renewable energy last longer | Rebates and tax credits |
By talking to a counselor or discussing with someone knowledgeable, you can find out more about these interesting points and maybe ask questions about the things you don’t understand yet.
2. (a) Understanding How Everyday Devices Transform Energy
Devices around us convert energy from one form to another to work. Here’s how three common devices do this:
Toaster
A toaster turns electrical energy into heat. When you plug it in and turn it on, electricity flows through the wires inside, which get hot and turn red. This heat cooks your bread.
Lightbulb
A lightbulb changes electrical energy into light and a little bit of heat. When electricity travels through the bulb, it heats up a tiny wire called a filament which glows and gives off light.
Cell Phone
A cell phone uses electrical energy stored in its battery to do many things. It changes this energy into light for the screen, sound for the speaker, and radio waves to send messages.
| Device | Energy Input | Energy Conversion | Energy Output |
|---|---|---|---|
| Toaster | Electricity | Electrical to Heat | Heat |
| Lightbulb | Electricity | Electrical to Light (and Heat) | Light (and Heat) |
| Cell Phone | Electricity (from battery) | Electrical to Light, Sound, and Radio Waves | Light, Sound, and Radio Waves |
These devices are examples of how we use different forms of energy in our daily lives to make things easier or more comfortable.
2. (b) Building and Understanding a Simple Energy Conversion System
Let’s create a small wind turbine system for a school project as an example of a system that makes at least two energy conversions.
- Wind to Mechanical Energy: When the wind blows, it pushes against the blades of the turbine, causing them to turn. This movement is mechanical energy.
- Mechanical to Electrical Energy: The spinning blades turn a generator inside the turbine. The generator converts the mechanical energy of the spinning blades into electrical energy we can use.
| Step | Energy Input | Energy Conversion | Energy Output |
|---|---|---|---|
| 1 | Wind | Kinetic (Motion) to Mechanical | Mechanical (Spinning blades) |
| 2 | Mechanical | Mechanical to Electrical | Electrical |
You can explain to a counselor that the wind turbine captures the wind’s energy, turns it into a form that spins the blades, and then changes that spinning action into electricity, which powers things like lights and computers.
3. Exploring Energy Efficiency in a Solar-Powered Light System
Let’s use a solar-powered street light as an example to understand energy efficiency.
(a) Parts of the System Affected by Energy Movement:
- Solar panels absorb sunlight.
- Batteries store the electrical energy.
- The light bulb converts the stored energy into light.
(b) System’s Primary Source of Energy:
- The sun, which provides solar energy to the panels.
(c) Useful Outcomes of the System:
- Illumination of streets at night.
- Conservation of electrical grid energy.
(d) Energy Losses of the System:
- Some sunlight is reflected and not captured by the panels.
- Energy is lost during the conversion from solar to electrical energy (in the panels) and from electrical to light energy (in the bulb).
| System Part | Energy Input | Useful Outcome | Energy Losses |
|---|---|---|---|
| Solar Panels | Sunlight | Electrical energy stored in batteries | Energy not absorbed (reflected light) |
| Batteries | Electrical Energy from Panels | Stored Energy | Energy lost as heat during storage and conversion |
| Light Bulb | Stored Electrical Energy | Light | Energy lost as heat when the bulb lights up |
This system is efficient because it uses renewable energy from the sun, reduces the need for grid power, and provides light without ongoing fuel costs. However, not all the energy from the sun is captured, and there are losses when energy changes form.
The Story of Energy
The story of energy begins far away in space with stars, like our sun. Imagine a star as a giant glowing ball, made mostly of a gas called hydrogen. The star stays together because gravity, an invisible pulling force, holds all the hydrogen in place.
A star shines and sends out energy because it turns hydrogen into a different gas, helium, and sometimes into even heavier stuff. Inside a star, it’s incredibly hot and squished, so when two hydrogen bits get pushed together really hard, they stick together to make helium. This sticking together is called ‘fusion.’
When hydrogen turns into helium, it gets a tiny bit lighter. This small bit that’s lost changes into energy that travels out into space. This energy from the stars comes to Earth and that’s part of the energy we use.
As stars get older, they make heavier things than helium, but they can’t make anything heavier than iron this way because it would take more energy than it makes. So, how do we get all the other heavier things? From big stars that blow up. These huge explosions are called supernovas, and they’re so powerful they create all the really heavy bits and scatter them through space.
Some of these heavy bits have energy inside them from when they were made, and over time, they let go of this energy. This is called ‘radioactive decay.’ Sometimes, when they let go of this energy, they shoot out tiny pieces, or they just let out pure energy and become more calm and stable. This is another way energy travels around, and it’s all part of the big story of energy that’s happening all across the universe.
Sun Energy
Think of the sun as a huge, glowing ball that’s like a giant power station. It sends out a lot of energy that travels across space. All around us, the energy we see and feel comes from this energy the sun sends out. It’s like the sun is sharing a little bit of its power with our planet, and even though we only get a small share, it’s enough to power up all the living things on Earth, grow our food, and even change the weather.
Imagine the sun’s energy as a giant wave made up of different types of light. Some of these types we can see, like the colors in a rainbow, and some we can’t, like the invisible rays that warm your skin on a sunny day.
Just like a big mix of different drinks—like coffee, tea, and juices—sunlight has different parts. But all these parts have one thing in common: they’re all forms of light. Just as most drinks are mostly water, all the different types of sunlight are forms of energy called ‘electromagnetic radiation’ or EMR for short.
Scientists break down this ‘light mix’ into seven main types so it’s easier to study and talk about them. These types start with the ones that have a little energy, like the warmth we feel, to the ones with a lot of energy, like the rays that can give you a sunburn. This whole variety of light is what gives us the energy we use every day.
| 1. Radio waves. People use radio waves to send information to receivers radios. Many stars and nebulae (dust and gas clouds in space) also give off radio waves. Another natural source is lightning. As a thunderstorm approaches, you hear crackles on the radio caused by bursts of radio waves created by lightning flashes. |
| 2. Microwaves. Stars and galaxies create natural microwaves. In microwave ovens, microwaves penetrate food and cause water molecules in the food to vibrate, producing heat to cook the food. |
| 3. Heat (infrared radiation). Heat possesses enough energy that we can feel it if it is intense enough. |
| 4. Visible light. Objects in the world around us scatter and absorb visible light. |
| 5. Ultraviolet. Ultraviolet light has enough energy in its waves to damage the receptors in our eyes or the outer layers of our skin. UV radiation is the cause of suntans, sunburns, and some forms of skin cancer. |
| 6. X-rays. X-rays have so much energy they can pass through our bodies and expose photographic film on the other side. Hot gases in our galaxy emit natural X-rays. |
| 7. Gamma radiation. This is energy so powerful it can penetrate deep through solid materials. Star processes or the decay of some radioactive atoms produces gamma radiation. |
Earthly Energy
The sun and other things in the sky, like stars and big clouds of gas, send out energy to Earth. This energy travels in waves that we can’t see. When stars get very old and explode, they create heavy bits called atoms that keep this energy.
Now, let’s talk about how this energy from the sky helps things happen on our planet. This sun energy touches the Earth and does a lot of work. It warms up our planet and gives light for plants to make food. It also helps to create weather patterns like wind and rain. All living things on Earth use this energy to grow, move, and live.
In simple terms, the energy from space is like a battery that powers everything on Earth. Without it, our planet would be too cold, dark, and lifeless.
1. Mechanical Energy
Mechanical energy is the motion energy of physical objects. Solar radiant energy can move objects, including air molecules in Earth’s atmosphere. As air molecules absorb heat from the sun, they gain energy and move faster.
As they move faster, they spread out. As they spread out, the air in a given space gets thinner, making it lighter, and it rises. The rising of heated air causes winds that have many powerful effects on Earth.
For example, if the wind becomes strong enough, it picks up sand and dust and becomes a powerful eroding force. Wind blowing over water creates waves and currents.
Wind pushes sailing ships, and it can help you ride your bike (or hold you back).
Another form of mechanical energy is the effect of the wind on movable solid objects. As wind vibrates leaves, a dining fly, or the siding on a house, it produces sound.
Any time the use of energy causes air vibrations, the result is sound waves. Sound carries the energy of molecules in motion.
Radiant energy has other effects on the natural environment. Heat, microwaves, and visible light all make water molecules move faster.
Solar energy increases the temperature at the surface of the oceans and adds energy to snow and ice until they are warmed enough to melt into water.
But probably the most important effect of the sun’s radiant energy on the water is to evaporate liquid water into water vapor, which rises into the atmosphere and is moved about by the winds.
When it cools, it condenses back into liquid water and falls as rain.
2. Chemical Energy
The sun’s radiant energy drives processes by which atoms form bonds that store energy. The best-known way this is done is photosynthesis.
A plant absorbs low-energy substances from its environment (mainly carbon dioxide and water) and, using radiant energy from the sun, builds complex molecules (glucose being the most important).
The complex molecules have energy stored in their bonds. The plant may use the energy in these complex molecules for its own growth, repair, and reproduction.
An animal may eat and digest the plant and use the energy released from the plant’s molecules to make molecules for its own use.
Also, burning the plant will release the chemical energy stored in the molecules. Burning gives radiant energy light and heat. This process of storing radiant energy in high-energy molecules has been happening on Earth for a long time.
Uncountable tons of plants and animals have lived, stored up the sun’s energy in their molecules, then died. In many places, large amounts of these plants and animals were buried under layers of sediment that turned to rock.
Under the pressure of the rocks and the heat from the interior of Earth, these materials became coal, oil, and natural gas. These forms of stored chemical energy are known as fossil fuels.
3. Nuclear Energy
The heat from inside Earth that helped form the fossil fuels is radioactive decay one of the few forms of energy that does not come directly from our sun. Radioactive atoms, formed in stars, release energy from their nuclei.
Inside Earth, a constant release of this energy continues to heat the interior. If not for this process, Earth would long ago have cooled to a frozen mass, even with the energy input of the sun.
Another form of nuclear energy, mentioned earlier, is fission. Fission occurs when very heavy atoms absorb neutrons (atomic particles) and split, converting mass to energy.
Today, the fission process is used in nuclear reactors in power plants that produce electrical energy.
4. Electrical Energy
Radiant energy from the sun produces electrical energy in nature by stirring the winds and clouds. This stirring builds up electrical charges in clouds and results in lightning. Lightning produces the flash of light (electrical energy) we see.
Another source of electricity in nature comes from certain electrochemical reactions. The most interesting of these may be the reactions in the bodies of electric eels that use bursts of electricity to stun prey and for defense.
Electrochemical reactions also produce electricity in most batteries. People have discovered that the most useful way to produce electricity is to move a strong magnet near a conductor like copper.
The field of the magnet causes an electric current in the conductor. Such a device is called a generator and is used in cars, power plants, and other places.
By using sources of mechanical energy, magnets can be spun inside coils of wire, producing huge amounts of electrical energy.
Also Read: Electricity Merit Badge
Energy Conversion Devices
Every useful process happens through the conversion of energy from one form to another. Before people invented cars, tractors, and power plants, they had only the muscle power of humans and animals.
Living animals (including humans) are complex systems for converting the chemical energy stored in food to heat and movement. Some of that chemical energy is used to make the heat that keeps our bodies warm.
When we use our muscles to breathe, pump blood, run, or pitch a tent, the muscles must have energy that comes from the food we ate. Other than muscle power, fire has been the most useful energy conversion.
Fire is an energy conversion from chemical energy to light and heat. Furnaces and heaters function to make heat available to keep us comfortable in cold weather. Many devices have been invented to make use of heat to help us accomplish other tasks.
1. Engine
An engine is any device designed to convert thermal (heat) energy into useful motion (mechanical energy). People have invented many different systems to accomplish this vital energy conversion.
Early steam engines used fire to power trains, ships, and farm machinery. Today cars, trucks, buses, trains, airplanes, and tractors get their power from internal combustion engines, which use fire inside a chamber in the engine.
A rocket engine uses the rapid burning of its fuel to provide the powerful pushing force to send vehicles into space.
2. Electric Motors
Electric motors are machines that convert electrical energy into mechanical energy. Many devices rely on electric motors creating movement when we need it. Fans move air and push air out of furnaces and air conditioners to heat and cool us.
Freezers and refrigerators use electric motors to move heat. The windshield wipers of cars work on electric motors. Water pumps, garage door openers, elevators, drawbridges, car hoists, and construction cranes all rely on electric motors.
Energy conversions are used to make electricity. Many power plants rely on a combustion boiler to use a chemical fuel to boil water into steam. Nuclear plants use a nuclear reactor as their source of heat and steam.
Steam-powered power plants need to convert the motion of the steam from a straight line into a circular, spinning motion. The device that does this is a turbine.
The spinning motion of the turbine shaft can then be connected to a generator, which converts this mechanical energy to electricity.
We often convert electrical energy into light. The most common electric light is an incandescent light, which superheats a wire inside a bulb until it glows.
Fluorescent lights are different and actually make two energy conversions. First, electrons passing through a mercury gas strike mercury atomns and give off ultraviolet light. The UV light strikes a coating on the inside of the tube and changes UV light into white light.
This effect is known as fluorescence. We also are able to convert electricity into a useful form of light with lasers.
3. Batteries
Batteries provide portable, stored electricity. They commonly power flashlights, radios, and other portable devices. Inside these batteries, reactions change chemical energy into electric current.
When all of the chemicals have reacted, the battery cannot be made to produce more electricity.
Storage batteries make use of two energy conversions. They use electricity to store chemical energy, then switch chemical energy back to electricity when needed.
A car battery is a storage battery that uses an acid solution and lead plates to store the electricity used to charge it.
Rechargeable lithium batteries produce electricity by transferring lithium atoms from the anode (negative pole) to the cathode (positive pole).
By applying electricity to the battery, the lithium atoms can be forced back to the anode. Then the battery is ready to use again.
Also Read: Electronics Merit Badge
4. Other Devices Convert Energy
So many other devices convert energy, it is impossible to name them all here. This list, however, may give you additional ideas for completing requirement 2.
- Radio transmitters convert electricity into radio waves, and radio receivers convert the radio waves back into electricity that speakers can change to sound (mechanical) energy.
- Solar cells convert radiant energy, or sunlight, directly into electricity.
- Explosives convert chemical energy into motion in a hurry!
- A car transmission takes in mechanical energy and gives out mechanical energy, but it allows us to control this energy more precisely.
- A computer takes in electricity and makes many changes to it to store and use the information it represents.
- Sailboats use the mechanical energy of the wind to create mechanical motion of the boat.
- Telescopes and microscopes work by gathering light energy and organizing it so we can see hidden objects better.
6. Table Forms of Energy
The Forms of Energy table lists devices that convert energy from one form to another. The columns represent the energy that is used, the rows show the energy that results.
Shaded boxes mean there is no practical device that makes the conversion described. For example, no way is known to use chemical energy to make atomic (nuclear) energy.
The first law of thermodynamics is good news for energy users because it tells how energy can be changed from one form to another to make it usable.
Many different devices use energy conversions to provide the systems that make modern
living possible.
