Ask an Expert about Electricity &
Energy Efficiency

 

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!

The Expert answers new questions regularly, so check back to see if YOUR
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Click on a question below to see the answer:

NEW! Why don’t you get shocked when you are standing on the ground?
—Janell

Answer: You don’t get shocked when standing on the ground because the ground is not a source of electricity. However, electricity is always trying to get to the ground, and your body is a conductor, so if you come in contact with a source of electricity while you are standing on the ground, you will be shocked because your body will become the pathway for electricity to travel to the ground.

I once saw a pair of shoes hanging from a power line. Why didn’t the shoes get burned up by the electricity in the line?
—Will

Answer: Shoes hanging on a power line don’t get burned for the same reason that birds standing on a power line don’t get shocked: they don’t give electricity a path to the ground, so electricity stays in the line and does not go through them. But if the shoes were to touch a power line and a power pole at the same time, they would provide a path to the ground and would get blasted with electric current. It wouldn’t be pretty!

By the way, if you ever see someone throwing shoes up onto a line, tell them to stop! The shoes can damage the power line, or someone trying to get the shoes down could be seriously shocked or even killed.

Is it true that cars could someday run on cow manure?
—Tyler

Answer: 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 manure 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.

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

Answer: Organic waste emits methane as it decomposes—or rots—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.

How much energy is in a bolt of lightning?
—Sophie

Answer: One lightning strike can carry up to 30 million volts—as much electricity as 2.5 million car batteries.

What kind of a difference does it really make to replace a regular light bulb with an energy-saving one?
—Anna

Answer: Replacing one incandescent light bulb with an energy-saving compact fluorescent bulb prevents about 1,000 pounds of carbon dioxide from being emitted to the atmosphere from power plants, and saves about $67 dollars in energy costs over the bulb’s lifetime.

Why didn’t Ben Franklin get killed when he tied a metal key to a kite string and flew the kite in a thunderstorm?
—Zachary

Answer: Ben Franklin’s famous key did give off an electric spark. But lucky for Franklin, the kite was just drawing small electrical charges from the air. If the kite had been struck by lightning, Franklin could have been killed!