A simple fact... energy saving light bulbs use less electricity than standard bulbs to do the same job.
Energy saving light bulbs use a fifth to a quarter of the electricity of ordinary bulbs to generate the same amount of light. So where you'd normally use a 60W bulb, you'll only need a 13-18W energy saving recommended equivalent. LED single spots are available with consumptions as low as 1W.
Time controllers, PIR (movement) sensors and/or lux (light level) sensors can be added to control new or existing lighting arrangements to reduce consumption to a minimum.