3.2 Efficiency of Energy Conversion Devices

Practice

The United States power plants consumed 39.5 quadrillion Btus of energy and produced 3.675 trillion kWh of electricity. What is the average efficiency of the power plants in the U.S.?

Step 1
To find the efficiency, both the units of input energy and the output energy have to be same. So we need to convert kWh into Btus.

Step 2
Use the formula for efficiency.