Although you may have noticed CFL (compact fluorescent lamp) light bulbs usurping the conventional incandescent light bulb in stores, until recently there has been next to nothing in the way of low energy replacements for the good old halogen spot lamp. CFLs cannot be made compact enough to retrofit existing lamps (which are often set into a very tight recess) and anyway they suffer from a variety of other problems such as being slow to startup and containing mercury.
However, LED (short for light-emitting diode) spot lights are now available in a range of beam angles and temperature colors so as to suit many different types of application. The beam angle determines how tight or wide the pool of light from the lamp is. Narrow beams are best used for task lighting and to highlight specific things, while wider angle beams tend to appear softer and are thus better for overall ambient and mood lighting.
Temperature color describes how “warm” or “cool” a light source appears. Paradoxically the temperature decreases for warmer light and increases for cooler light. If you need to know technical details, then what is often described as “warm white” should be in the range 2500-3000 Kelvin which is about the same as a conventional halogen lamp.
Values above that are variously described as “cool” or “daylight white” and although they result in superior color rendering (how accurately colors are depicted under artificial light), most people find them a bit too clinical for domestic use. Anything higher than about 4000K will look very distinctly blue.
All LED spotlights support the industry standard fittings, so you can replace existing spotlights with MR16 and GU10 LEDsby quite simply pulling out the old lamp and installing an LED equivalent in its place.
As well as spotlights, there are also now some conventionally shaped LED light bulbs that are starting to surpass what CFLs can offer, with considerably longer life spans and even lower energy consumption, so it seems likely that CFL will turn out to be merely a passing footnote in the LED lighting revolution.