Fluorescents lamps – both linear and compact – work differently from incandescents since light is produced by electricity flowing through a gas.

All Linear and some Compact lamps require control gear for their operation. Household Compact Lamps (Energy-saver or CFL-i Lamps) have their control gear built into them and can be plugged directly into a suitable light socket.

Linear versions come in three 'whites': warm white (2700K), cool white (4000K), and cool daylight (6500K); Linear lamps are not currently able to be retrofitted into existing light fittings as they require control gear for their operation.

Integrated compact fluorescents (CFL-i) can be used in this way and they are a great replacement for incandescent and mercury vapour lamps – typically a 45W CFL can replace a 200W incandescent or an 80W mercury vapour lamp.