Energy EfficiencyA standard incandescent light bulb converts about about 2% of its energy consumption to light and 98% to heat. In an air conditioned room in a hot climate, this is quite inefficient.
Work EfficiencyUnder ideal conditions, a particular programmer can write about 1000 lines of code in a day. One day, the programmer works from home and watches a few movies as she works. She produces only 100 lines of code. This represents efficiency of 10%. When she goes to the office efficiency drops to 7% due to meetings, commuting time and socialization with coworkers.
Process EfficiencyAn ideal process can set up a customer's bank account for $20. The actual process costs $100. Waste is 80% and efficiency is 20%.
Solar PanelsA particular solar module can convert 20% of available solar energy to electricity under ideal conditions.
Device EfficiencyA pair of speakers use 50% of the energy they consume to generate sound.
VehiclesAn electric vehicle directs about 60% of its energy consumption to its wheels.
The percentage of effort that produces a result.
The percentage of resource potential that is utilized to produce a result.
The percentage of resource potential that is not wasted.