Where does electricity come from?
Before the past few days, you might have answered “the switch on the wall in my bedroom.”
But if yours was among the more than 1 million houses that lost power this weekend (or among the hundreds of thousands still without power), you know that that really isn’t the answer.
Taking electric power for granted is natural. But while you’re really thinking about — and appreciating — electricity, we thought we would explain how it gets from the power plant to your house. Clay Anderson of Pepco, a major power company in the area, talked to KidsPost about how electricity goes from being created to lighting up your room.
Power is generated, or made, at a power plant where enormous spinning turbines produce power. “As they spin, the electrons start to move quickly and that’s how electricity is created. But once electricity is created, it’s not like a bottle of water that can be stored; it has to be distributed,” Anderson said. Because all that electricity at a power plant doesn’t do you much good if you want to watch television or get a cold drink from the refrigerator, the power needs to get closer to your house.
From the power plant, the electricity moves along hi gh-voltage power lines. (A volt is a measure of electricity). You’ve seen high-voltage power lines. They are lines that can carry power over long distances, and they’re held up by enormous towers. The power then moves into a transmission station.
A major purpose of a transmission station is to change the energy from the high-voltage levels, as high as 65,000 volts, to lower levels that can be distributed (or delivered) to homes and businesses.
“This is called marching down or stepping down” the power, Anderson said.
The number of volts marches down several times as the power moves through substations (32,000 volts) and to 7,000 volts at transformers. No, Anderson isn’t talking about Autobots and Decepticons. Instead he’s talking about the drum-shaped devices on power poles outside your house or large green boxes that you see every few houses if your neighborhood has underground power.
Those transformers are the last step in getting the electricity to be usable in your house. They convert electricity all the way down to 120 volts, which is what your house uses.
So if you have underground power cables, you might be wondering why you lost electricity at your house. Can you see the answer now? Before the electricity gets underground to your power lines, it has to travel over above-ground power lines. “Every cable that is underground is like a Metro train,” Anderson explained to us. “It has to come out an above-ground transmission wire.”
Those lines may have been damaged by the winds, rain and downed trees of Friday night’s storm. An interruption anywhere along the path that electricity travels can leave your house powerless.
Another thing you may be wondering is why some people in your neighborhood have power but you don’t. That’s because of the power grid. Anderson said KidsPost readers should think of it as a checkerboard. Your house may be on a red square and your neighbor’s house may be on black. Different squares get power from different lines, which are called “feeders.” One side of a street may be connected to one feeder and the other side to another. “Everyone can’t be connected to the same feeder or it would be like spaghetti,” Anderson said.
Of course, if you’re reading this in a house without power, none of this makes you feel any cooler. But hopefully, you’re a little less bored and you’ll never again think that electricity comes from that switch on the wall!