A wind turbine takes in energy from wind with the goal of converting it into electrical energy. Much of the wind energy is also converted into the kinetic energy of the spinning turbine and heat lost to the air around it.

Question

An illustration of a windmill with a wide arrow away from it labeled kinetic energy of wind 3000 J and it separates into 3 different arrows, one labeled electric energy 750 J, the second labeled heat 750 J and the third which is the widest labeled kinetic energy of turbine blank J.
If the goal of the turbine is to put out electric energy, what is the efficiency of the turbine?

25%
50%
75%
100%

Answer 1

To calculate the efficiency of the wind turbine, we can use the formula for efficiency, which is:

\[ \text{Efficiency} = \left( \frac{\text{Output Energy}}{\text{Input Energy}} \right) \times 100% \]

In this case, the output energy is the electrical energy produced by the turbine, which is 750 J. The input energy is the total wind energy, which is 3000 J.

Substituting these values in:

\[ \text{Efficiency} = \left( \frac{750 \text{ J}}{3000 \text{ J}} \right) \times 100% = \left( \frac{750}{3000} \right) \times 100% \]

Calculating the fraction:

\[ \frac{750}{3000} = 0.25 \]

Now, converting it to a percentage:

\[ 0.25 \times 100% = 25% \]

So, the efficiency of the turbine is 25%.