Grow light daylight bulb energy saving bulb energy rating a power 15 watt energy consumption 15 kwh1000h series megaman plant lamp socket e27 voltage 230 v light colour daylight white lifespan 10 000 h bulb shape compact fluorescent tube length 150 mm average annual electricity cost 01951 kwh 293 euros source average electricity cost based on figures from eurostat as of 2016