Their "efficiency" is light output vs electrical input. The result is actually that it starts converting heat as well as electricity into light. So you get more energy in light out than you put electricity in. You just put more energy in than electricity.
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Their "efficiency" is light output vs electrical input. The result is actually that it starts converting heat as well as electricity into light. So you get more energy in light out than you put electricity in. You just put more energy in than electricity.