With the move to more low energy bulbs it is an important consideration when purchasing lights to check what bulbs the fitting uses. Most lights nowadays will accommodate either standard incandescent or low energy bulbs. Halogen light bulbs can be either mains or low voltage and there are more low energy options of these bulbs becoming available. Check whether halogen bulbs can be dimmed, Mains halogen bulbs can be dimmed but many low voltage halogen bulbs cannot. LED lights are very low energy and last a long time but check they will give you the light level you want.