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Energy Efficiency FAQ (Frequently Asked Questions)
Do you need to write a report about energy? Or maybe just want to know more about some aspect of energy that’s caught your interest? You’ve come to the right place. Simply click on the questions below, and you’ll be on your way!
- How do power plants make electricity?
- Why is it important for people in the United States to save electricity and other forms of energy? Aren't we just a relatively small part of a large planet?
- What kind of a difference does replacing a regular light bulb with an energy-saving bulb really make?
- Which type of renewable energy is currently most relied on in the United States?
- What's the difference between global warming and the greenhouse effect?
- Since global warming is already in effect, isn't it too late to make a difference through energy efficiency and conservation measures?
- How can planting trees help counter the effects of global warming?
- We don't have a hybrid vehicle, and can't afford to buy one right now. So, since my parents need to drive to work and drive me to school, it seems like reducing the amount of gas we use isn't really possible, is it?
- Is it true that cars could run on cow manure?
- I have heard that landfills can be a source of energy. How does that work?
- What are the “three Rs” of energy conservation?
- How is energy measured?
- What are some good ways to save energy at school?
- How does a compact fluorescent light (CFL) work?
- How does a light-emitting diode (LED) work?
1. How do power plants make electricity?
Various energy sources are used to turn turbines. The spinning turbine shafts turn electromagnets that are surrounded by heavy coils of copper wire inside generators. This creates a magnetic field, which causes the electrons in the copper wire to move from atom to atom.
2. Why is it important for people in the United States to save energy? Aren't we just a relatively small part of a large planet?
Although Americans make up only 4.5% of the world's population, we use about 19% of the world's energy!
3. What kind of a difference does replacing a regular light bulb with an energy-saving bulb really make?
Replacing one incandescent light bulb with an energy-saving compact fluorescent bulb prevents 1,000 pounds of carbon dioxide from being emitted to the atmosphere from power plants, and saves $67 dollars in energy costs over the bulb's lifetime.
4. Which type of renewable energy is currently most relied on in the United States?
Hydropower. In 2010, it accounted for 6% of all the electricity generated in the United States, and 66% of all the electricity generated from renewable energy. (Source: U.S. Energy Information Administration, Electricity in the United States)
5. What's the difference between global warming and the greenhouse effect?
The greenhouse effect is created because certain gases sent into our atmosphere, such as carbon dioxide, allow radiation from the sun to pass through the earth's atmosphere, but prevent a portion of the infrared radiation from the earth's surface and lower atmosphere from escaping into outer space. This process occurs naturally; without it our planet's temperatures would be about 60° cooler! Life as we know it simply would not exist without the natural greenhouse effect. However, global warming is happening because the greenhouse effect has become intensified primarily by the burning of fossil fuels, which adds more carbon dioxide and other gases to the atmosphere and increases the warming process.
6. Since global warming is already in effect, isn't it too late to make a difference through energy efficiency and conservation measures?
No! If we get serious about energy-saving practices, we can lower our energy costs by several hundred dollars per household per year and reduce greenhouse gas emissions.
7. How can planting trees help counter the effects of global warming?
Trees take carbon dioxide out of the air and give back oxygen, thus helping reduce the excess of greenhouse gases hovering in the atmosphere and heating up the planet.
8. We don't have a hybrid vehicle, and can't afford to buy one right now. So, since my parents need to drive to work and drive me to school, it seems like reducing the amount of gas we use isn't really possible, is it?
Of course it's possible! There are numerous other ways to reduce gasoline usage short of switching to a hybrid or electric vehicle. Carpooling, biking, and walking are three excellent ways to significantly reduce gas usage, as are telecommuting for work and riding public transportation. Also, combining trips to school or work with routine errands cuts down significantly on miles traveled.
9. Is it true that cars could run on cow manure?
Yes! Manure can be made into a gas containing methane. (Methane is the same energy-rich gas found in natural gas.) Certain types of bacteria emit this gas as they consume the waste collected in special air-free tanks. The mixture of gases produced in this way, called biogas, can then be used in some modified car engines instead of gasoline, or burned in a boiler to generate heat or electricity.
10. I have heard that landfills can be a source of energy. How does that work?
Just like manure, other types of organic waste emit methane as they decompose—or rot—in the landfill. Landfills can collect and treat the methane, and then sell it as a commercial fuel, or they can burn it to generate steam and electricity. Today, there are almost 400 gas energy landfill projects operating in the United States.
11. What are the “three Rs” of energy conservation?
Reduce, reuse, and recycle. Some ways you can reuse items to reduce waste are to bring your lunch in a lunch box instead of a paper bag, use both sides of each sheet of paper, buy products in bulk, bring your old grocery bags to the store when you shop, and give away old toys and clothes. Encouraging your family and school to recycle cans, bottles, papers, and plastics is also an excellent way to conserve energy and natural resources.
12. How is energy measured?
There are many ways to measure energy. One of the basic measuring blocks for energy is called a “BTU,” standing for British thermal unit. A BTU is the amount of heat energy it takes to raise the temperature of a pound of water by one degree Fahrenheit, at sea level. One BTU equals the heat generated by about one blue-tip kitchen match. One thousand BTUs are roughly equivalent to the energy your body receives from eating an average candy bar.
13. What are some good ways to save energy at school?
Make sure the lights and computers are turned off before recess and lunch, and after school; make sure books and furniture do not block the vents in your classroom; keep doors and windows closed when heating or air conditioning is running; turn off the water in the bathroom when you are finished using it; report any water leaks you find to an adult.
14. How does a compact fluorescent light (CFL) work?
Compact fluorescent lights (CFLs) and other fluorescent light bulbs contain gases (argon and mercury vapor) that produce invisible ultraviolet (UV) light when stimulated by electricity. When the UV light hits the white phosphor coating inside the fluorescent bulb, the phosphor illuminates or "fluoresces," changing the UV light into visible light. CFLs are very energy-efficient, using only about one-fifth the energy of a standard incandescent bulb. This is because all of the electricity they use goes toward creating light, whereas the energy used by standard incandescent bulbs creates heat as well as light.
15. How does a light-emitting diode (LED) work?
Like their energy-efficient cousins, CFLs, LEDs don't waste energy on heat so they don't get especially hot. But unlike CFLs, LEDs are illuminated solely by the movement of electrons in a semiconductor material. A semiconductor is a material with electrical conductivity (meaning the ability to transfer electrical energy) between that of a conductor and an insulator (hence the prefix "semi"). Inside an LED, when an electrical current passes through the semiconductor material, electrons move through the material and drop to other energy levels, and in the process they emit photons of light. LEDs are becoming an increasingly important and common light source because of their high degree of energy efficiency. We see them particularly in Christmas tree lights and the tubes that light up LED HDTVs.
