This is easier to think about, if you consider the extremes. A very low power bulb generates no visible light, but still consumes energy. This is super ineffici

This is easier to think about, if you consider the extremes. A very low power bulb generates no visible light, but still consumes energy. This is super inefficient. At higher temperature the peak shifts to longer wavelengths (i.e. visible). You can compare the black body radiation at different temperatures using Planck's law.[1] [1] https://en.wikipedia.org/wiki/Planck%27s_law#/media/File:Black_body.svg https://en.wikipedia.org/wiki/Planck%27s_law#/media/File:Bla...