Efficiency of an Electromechanical System
Engineers have taken the ancient water wheel and applied its process to modern water turbines that generate power with great efficiency.Copyright National Park System http://www.nps.gov/sair/planyourvisit/things2do.htm
Students use LEGO® motors and generators to raise washers a measured height. They compare the work done by the motor-generator systems with the energy inputs to calculate efficiency.
With most energy conversions, some energy is lost in the process, so engineers improve the energy efficiency of systems to reduce energy consumption. Engineers have learned that more complicated processes that have many components are typically less efficient than simple systems. Making systems that include energy conversions more efficient can help to reduce our consumption of fossil fuels and reduce greenhouse gas emissions.
After this activity, students should be able to:
- Explain where energy is "lost" in conversions and why.
- Compute the efficiency of an energy conversion given input and output.
- Identify system by-products and explain how they can be used effectively to increase overall system efficiency.
- Design a simple energy conversion system and test its efficiency.
- Use collected data to calculate the efficiency of a system.