Fluorescent light energy rating b power 15 watt energy consumption 15 kwh1000h series osram lumilux t8 socket g13 light colour neutral white light output 950 lumen colour temperature 4 000 k lifespan 18 000 h bulb shape tube light length 440 mm diameter 26 mm average annual electricity cost 01951 kwh 293 euros source average electricity cost based on figures from eurostat as of 2016