Representing energy output of wind turbine

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user0330
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Representing energy output of wind turbine

Post by user0330 »

Hello, I'm doing the project "Make the Wind Work for You" for my 6th grade science fair. My question is, how do I represent energy produced by the wind turbine by the amount of weight lifted by the wind turbine? Is there a formula that directly relates the weight lifted to the energy output? Thank you.
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Re: Representing energy output of wind turbine

Post by bfinio »

Hi user0330,

There are two equations you need to know, and you probably did not learn these in school yet (normally you might not learn them until high school physics). One is:

Potential Energy = mass * gravity * height

this is typically abbreviated

PE = mgh

This equation tells you how much potential (stored) energy an object has based on its height off the ground. Energy is measured in a unit called joules, abbreviated J.

The other is

Power = Energy / Time

or

P = E/t

Power is measured in a unit called watts, abbreviated W. You might also see this equation written as

Power = Work / Time

or

P = W/t

"Work" is a word physicists use to describe "the amount of energy it takes to do something." Work is also measured in units of joules (J).

A lot of beginner students get power and energy mixed up. The important difference to remember is that power depends on time, and energy does not. In other words, the power produced by the wind turbine depends on how fast it lifts the weight. This is what you want to measure. You can do that by measuring the mass of the weight, using a ruler to measure the final height of the weight, and using a stopwatch to measure how long it takes the weight to get from the bottom to the top. Then use the equations above to calculate power.

If you only calculated energy (which does not depend on time), you would always get the same result, because the weight ultimately ends up at the same final height, even if it gets there slower. Hope that makes sense.

I would recommend doing some more background research about the equations and units I mentioned. It is important to use the proper units when doing the calculations or you will not get the right result (for example, to get an energy in joules, you need to measure the height in meters, not centimeters or inches).

Hope that helps!

Ben
user0330
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Joined: Sun Jan 03, 2021 1:30 pm
Occupation: Parent

Re: Representing energy output of wind turbine

Post by user0330 »

Hello, Ben.

Thank you so much for your quick response! Your explanation is very helpful, and calculating power definitely makes sense for this project.

--Jules
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