On a family drive, Raven spots a huge concrete dam holding back a lake. Water roars out of gates at the bottom.
Farther along, Rocket points at rows of wind turbines turning on a ridge.
"They look totally different," he says. "But I bet they do the same job."
Raven presses her nose to the window. "What do you notice that both of them use?"
Nova blinks thoughtfully. "Here is a clue," she says. "Both have something spinning inside."
Many power plants use machines called generators. A generator converts motion energy into electricity.
In a wind turbine, the wind turns the blades. The blades turn a shaft that spins a generator.
At a hydropower dam, moving water pushes and turns the blades of a turbine. The turbine spins a generator.
A solar cell is different. It converts sunlight straight into electricity with no spinning at all.
| Converter | Energy in | Energy out |
|---|---|---|
| Wind turbine | motion of wind | electricity |
| Hydropower dam | motion of falling water | electricity |
| Solar cell | sunlight | electricity |
A wind turbine, a dam and a solar cell all have the same goal: make electricity.
The turbine and the dam start with motion. Wind or water turns blades.
The blades spin a generator, which converts motion into electricity.
The solar cell starts with light and has no moving parts to spin.
| Statement | True or false? |
|---|---|
| A generator converts motion into electricity. | ? |
| Many power plants use generators. | ? |
| A solar cell spins a generator. | ? |
| A wind turbine uses the motion of wind. | ? |
What a powerful week! Tomorrow at Launch Lab, your family designs an even better roller.