Fluorescent light energy rating b power 18 watt energy consumption 18 kwh1000h series osram dulux l sp socket 2g11 light colour warm white light output 1 200 lumen colour temperature 3 000 k lifespan 15 000 h bulb shape compact fluorescent tube average annual electricity cost 01951 kwh 351 euros source average electricity cost based on figures from eurostat as of 2016