Around 14% of the electricity consumed in Switzerland is used for illumination. In addition to lamps (also known as illuminants), generating light also requires luminaires and – depending on the technology in use – additional control systems. These components need to be optimally aligned to create good quality light.

The energy efficiency of lamps as used in the home has to be declared on an energy label. In addition to the energy efficiency class, the label also provides information on power uptake and luminous flux (lumen). An optional declaration of lifetime in hours may also be included.

A conventional light bulb converts 95% of the energy it consumes into heat, but only 5% into visible light. It is therefore worthwhile to pay attention to efficiency ratings when purchasing light bulbs. Remember to take the colours of the room into account: rooms with light colours need a much lower light output than rooms with dark colours.