Efficiency is defined as an [energy conversion process]. This conversion process is useful energy or work output divided by total energy input or energy stored multiplied by one hundred percent.
Efficiency values generally range from five percent to ninety five percent. Five percent accounts for incandescent light bulbs where ninety five percent is fort the best electrical motors, which convert electrical energy into mechanical energy.
During higher (increased) efficiency levels, this is interpreted as energy that can do the same job, but requires a smaller amount of energy.
Each electrical device has a different level of efficiency. [The laws of thermodynamics] places a limit on the efficiencies that can be attained while trying to obtain some energy conversions.
Efficiencies are obtainable by either: 1. Mechanical energy to electrical. 2. Electrical to mechanical. 3. Chemical to thermal. 4. Chemical to thermal to mechanical to electrical. 5. Nuclear to thermal to mechanical to electrical. 6. Chemical to thermal to mechanical. 7. Electrical to light. 8. Light to electrical.
The devices with the smaller efficiencies include solar light and incandescent lamps. The devices with the larger efficiencies include gas furnaces and also electrical generators.
If a multi-step process is necessary the [overall efficiency] is equal to the product of each individual efficiency.
“Efficiency” and efficiency charts are found inside our textbooks on pages 79-81.
- Kristen Weschler (10-05-07 4:41 PM)