Dynamo (noun)

1. A machine that converts mechanical energy into electrical energy.
2. A person or thing that generates energy, power or activity.

Origin:

Mid 19th century: from greek dunamis "power" + -o- (as in magneto).

Examples:

1. The generator is a large dynamo that converts mechanical energy into electrical energy.
2. The team captain is a real dynamo on the field.
3. The company's new CEO is a real dynamo.
4. The company invested in a new dynamo to increase power production.
5. The dynamo was a vital component in the early development of electricity.