Halogen light pin socket bulb power 20 watt energy consumption 20 kwh1000h series osram halostar starlite equivalent to light bulb 25 w socket g4 voltage 12 v light colour warm white light output 300 lumen colour temperature 3 000 k lifespan 4 000 h style glass bulb average annual electricity cost 01951 kwh 39 euros source average electricity cost based on figures from eurostat as of 2016