Energy FAQs (Frequently Asked Questions)


Have you ever wondered why shoes hanging on a power line don’t get fried? Or why natural gas flames are blue? Now you can find answers to these and other energy-related questions.

We post new questions and answers regularly, so check back!

Click on a question below to see the answer:

NEW! What are Natural Gas Vehicles?

Answer: Vehicles that run on natural gas instead of gasoline are called natural gas vehicles (NGVs). There are about 110,000 NGVs on U.S. roads today and over 12 million worldwide. NGVs are a popular transportation choice because they run cleaner than other vehicles. Compared to gasoline or diesel-powered vehicles, they produce much lower levels of pollutants and cost less to maintain. Also, natural gas costs, on average, one-third less than conventional gasoline at the pump.

What is an electromagnet?

Answer: An electromagnet is a device in which a magnetic field is produced by a flow of electric current. It consists of copper wire that is connected to a battery and wrapped in coils around an iron core. The strength of an electromagnet can be changed by adjusting the amount of electricity flowing through it. This can be done by varying the number of coils in the wire or varying the size or number of batteries that are used.

Why do people say you should unplug appliances and chargers when not in use?

Answer: TVs, DVD players, computers, kitchen appliances, and chargers all can draw power even when off. You can stop these “phantom energy users” by unplugging them between uses. To make it easier, plug them into a surge protector and shut it off when idle for long periods.

How is electricity produced in power plants?

Answer: In power plants various energy sources, such as fossil fuels (coal, oil, natural gas) or renewable energy sources (such as water, the sun, wind, biomass, or geothermal) are used to turn turbines. The turbines turn electromagnets that are surrounded by heavy coils of copper wire. The moving magnets cause the electrons in the copper wire to move from atom to atom, generating electricity.

Could the flame on my stove get too hot and start a fire?

Answer: It is not the heat of the flame that makes it unsafe when flammable objects—like papers, potholders, paper towels, or toys—are left nearby where they could catch on fire. To prevent this from happening, keep flammable items well away from the stove. Always keep the flame no larger than the bottom of the pot or pan in use, and never leave an open flame or a working stove unattended.

How much energy can be saved a year in your house if you turn out the lights every time you leave a room?

Answer: This is a hard question to answer accurately without knowing the details of your situation, but here are some estimates. Let's say your family spends about $2,000 per year on energy. Lighting accounts for about 12% of most people's home energy bill, so $240 of that $2,000 would go toward lighting. If you can use only half as much energy for lighting as you do now by turning off the lights whenever you leave a room, you’ll save about $120 per year. Of course, your actual results will depend on how many lights you have and how long they are generally on. And switching from incandescent bulbs to CFLs will greatly reduce your energy use immediately.

Can you see electricity flowing in power lines or electrical wires?

Answer: You can't see electricity when it is flowing through a circuit. But if electricity leaves the circuit, as it does when someone is shocked, you can see a spark. The spark isn't electricity itself. It is a flame that occurs when the electricity travels through the air and burns up oxygen particles.

Does everything use energy?

Answer: Well, yes and no. Yes, because you need energy to make anything happen—it’s what makes anything and everything move, change, and/or grow. Everything that happens does so because of energy, and all living things use energy. But everything in the world does not use energy. For example, a rock on the ground and a car parked in a driveway do not use energy while they are sitting still. However, if you want to move the rock, or drive the car, you need to use energy to do that.

I have heard that landfills can be a source of energy. How does that work?

Answer: 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.

 What's the difference between global warming and the greenhouse effect?

Answer: 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 degrees cooler! Life as we know it simply would not exist without the natural greenhouse effect.

However, many scientists believe global warming is happening because the greenhouse effect has become intensified by human activities (primarily the burning of fossil fuels), which add more carbon dioxide and other gases to the atmosphere and increases the warming process.