Halogen light pin socket bulb reflector lamp power 20 watt energy consumption 20 kwh1000h series osram decostar 51 equivalent to light bulb 25 w socket gu5 3 voltage 12 v light colour warm white luminous intensity 510 cd colour temperature 2 800 k beam angle 36 lifespan 2 000 h bulb shape reflector variable intensity dimmable diameter 51 mm average annual electricity cost 01951 kwh 39 euros source average electricity cost based on figu