Hey fellas quick question,

if for example a light bulb has a power conversion efficiency of say 20% does this mean 20% of electrical input power will be light and 80% heat? or the other way around?

cheers,

 

Hey fellas quick question,

if for example a light bulb has a power conversion efficiency of say 20% does this mean 20% of electrical input power will be light and 80% heat? or the other way around?

20% goes to light.

 

In general, "efficiency" is the percentage of something that actually goes to what you want.

 

Hey fellas quick question,

if for example a light bulb has a power conversion efficiency of say 20% does this mean 20% of electrical input power will be light and 80% heat? or the other way around?

cheers,

Hi,

Yeah that's pretty much it although the more correct term is efficacy when describing the bulb energy conversion itself.

So that particular light bulb is 20 percent efficient at producing light, and 80 percent efficient at producing heat.
So used as a light bulb to produce light, 20 percent, but as used as a heater 80 percent provided the light output is not absorbed and also turned into heat which in that case would make it 100 percent.