Science Buddies: "Ask an Expert"

Hello! My name is Stephanie and I am interested in researching small scale energy generation from waste energy. I have a few questions:
1) How is "the amount of energy" measured in the form of electricity? In Watts?

2) How are Watts different from coulombs, amperes, and volts etc? (It gets me a bit confused still and I am not completely sure what each means on a label for a battery or electrical device).

3) Energy can never be "created." Thus while you can amplify the voltage to power a greater energy-consuming device, how come you can supply more power if energy is actually the same?

4) What are the best piezoelectric materials for energy harvesting?

Thank you so much and I look forwards to hearing back!

Hi Stephanie,

Science Buddies has a great tutorial on electricity that should help with your questions about energy, power, charge, current and voltage:

https://www.sciencebuddies.org/science- ... lectricity

The electrical energy in a circuit can't be any greater than that the energy available from the source (battery, wall outlet, etc). An amplifier circuit uses some of the energy from the electrical source to boost the voltage and/or current.

I think the “best” piezoelectric material for energy harvesting would depend on the design of the device doing the harvesting. For example, you might want small piezoelectric discs if you wanted to make a battery charger that fits in running shoes. Or you might want larger devices if you were making a sidewalk that generates electricity.

By the way, there are several projects on energy harvesting here on Science Buddies that may be of interest to you. Three examples are:

https://www.sciencebuddies.org/science- ... mpost-pile

https://www.sciencebuddies.org/science- ... ind-energy

https://www.sciencebuddies.org/science- ... om-the-sun

I hope this helps. Please ask again if you have more questions.

A. Norman