Example 1: Yearly electricity consumption for illumination.

If you use light sources that are based on traditional incandescent bulbs halogen bulb compact fluorescent lamps (CFL) bulb light emitting diodes (LED) bulb , for hours daily on average you will consume kWh of electricity over the year, that cost £.

Calculation assumes electricity price of £/kWh and ~1100 lumen brightness of each light source).