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Have you ever wondered why shoes hanging on a power line don’t get fried? Or whether cars could someday run on cow manure? Now you can get answers to these and all your energy-related questions. Just Ask an Expert!

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NEW! Where does electricity come from?
— Anonymous

Answer: Electricity starts with atoms, the tiny particles that make up everything around us. Even tinier particles called electrons orbit the centers of atoms. When electrons move between atoms through a wire, electricity results. Electricity is typically produced at power plants. (For more on this topic, please see my answer to the question below.)

How is electricity produced in power plants?
— Nikos

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.

How is natural gas useful as an ingredient in medicine?
— Timothy

Answer: Natural gas is not used directly as an ingredient in medicine, although it once played a role indirectly. Natural gas is used in the manufacturing of many chemicals. Among these chemicals is ethylene, which was once a common medical anesthetic.

How does wind energy work?
— Darwin

Answer: When the sun heats air close to the ground, the warm air rises. This is the beginning of wind. The air molecules have absorbed the potential energy from the sun’s rays and started to move. Kinetic energy, the energy of motion, also plays a role in wind energy. A wind turbine has fan blades called rotor blades. As the wind moves over the rotor blades, they begin to turn. The energy created by this movement is transferred to an electrical generator. The generator produces electricity by spinning a magnet inside a coil of wires. When the magnet turns, it pushes electrons through the wires and generates electricity.

How do workers work with power lines and power poles? Do they have to stop the electrical flow?
— Kali

Answer: Utility workers and linemen are trained to work safely around live, energized power lines. They use insulated tools and equipment to touch the wires. The most common tool is called a hot stick. It is a long pole with a hook that can grab the wire. The linemen wear special protective gear that helps prevent shock, including insulated boots, hardhats, and gloves, as well as fire-resistant clothing. This gear is tested regularly to make sure it does not have even the tiniest hole or crack that could allow electricity through. In situations where a live, energized power line would be too dangerous to work on or near, utility workers do stop the electrical flow first.

What is the best way to stay safe if you are caught in the middle of an empty field during a lightning storm, and absolutely cannot get to a safe place?
— Kali

Answer: If you are caught in a field where there is danger of lightning, the safe thing to do is to crouch down but NOT lie down. Bend your knees and squat, while keeping your feet together and on the ground, so that the part of you touching the ground is as small as possible. Cover your ears to prevent damage to your hearing from thunder, and stay at least 15 feet away from other people. Make sure you stay away from objects that conduct electricity such as tractors, golf carts, golf clubs, metal baseball bats, metal fences, motorcycles, lawnmowers, and bicycles.

What is the difference between stored energy and energy in motion?

Answer: Stored energy (also called “potential energy”) is the energy in matter due to its position or the arrangement of its parts. For example, a coconut hanging on a palm tree has stored energy because of its position suspended in the air. When the coconut drops from the tree and falls to the ground, its potential energy is converted into energy in motion (also called “kinetic energy”). Another example that illustrates the difference between these two types of energy is a twisted-up rubber band used to fly a toy airplane. The rubber band contains potential energy that is converted into kinetic energy when it untwists and turns the propeller.

What is the sun made of?

Answer: The sun is made up of very hot gases, mostly hydrogen and helium. About 1% is oxygen, and another 1% is a combination of other elements, including iron, nickel, silicon, sulfur, magnesium, carbon, neon, calcium, and chromium. Astronomers believe the hydrogen and helium came from the Big Bang, or birth of the Universe, and the other elements were released by dying stars.

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.

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.