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Is that true?

My physics is admittedly not great. However I though a 100% efficient lightbulb generates just as much heat, but at the place where the photons land (walls, floor, etc) rather than at the bulb.

I think basically any time we use energy, whether by running current through a lightbulb it by respiration after eating food, it ultimately ends up as heat.

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The energy we use starts out as kinetic (wind, water), or heat (solar, thermal), or chemical, etc. We then use and it get it to do work, which in most cases converts much of it back into kinetic energy, and where there is inefficiency, heat, but even that part can end up in sinks which can find themselves ultimately back in places where heat already resided.

> which in most cases converts much of it back into kinetic energy

Are you thinking of transportation here? We burn fuel to add kinetic energy to a car or airplane but, by the time the vehicle has stopped moving, all of that energy has been converted into diffuse heat in the wheels, brake pads, atmosphere, etc, never to be harnessed again for the mostpart.

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