I have been in LED's for last 15 years (mostly in flashlights). It always bugs me that they waste so much power in heat. If I had wanted heat, I would be using incandescent! I understand the physics and rationale for the heat sink but the efficiency would so high only if the heating could be eliminated. It is not like incandescent bulbs where heat generates the light. Heat in the LED is because LEDs are driven extremely hard.