A clean energy future
I just watched this video about energy dependence and it got me thinking about some stuff.
In particular, it struck me how one of the quoted figures is that even LED lighting is only about 30% efficient in its conversion from final energy to usable light. My experience with LED lighting has been that 120V AC lamps do indeed generate a lot of heat, and I guess 30% sounds about right, but so much of that heat is just from the power circuitry: namely from having to convert AC to DC and step the voltage down.
But does it have to be that way?