Fixtures
If you're thinking of updating your fixtures, replacing incandescent bulbs is an absolute must. The energy-conscious consumer therefore has two main choices: LED and fluorescent.
Anyone who's worked in an office in the last 50 years is almost guaranteed to be familiar with fluorescent fixtures, though the popular view of them is inaccurate in modern times. Most people assume fluorescent lights take a few seconds to start with the well-known "plink-plink-buzz" sequence; that they produce a very bright, washed-out white light; that they are not recyclable; that they make a lot of annoying noise; that they are efficient but are only available in sizes that suit businesses, not homes.
The reality is that modern fluorescent lights rarely buzz, that they are recyclable and that steps have been taken to improve their color rendition and size availability. Their lifespan is around 9 years (at 3 hours' use per day) and they use 75% less energy than an incandescent source. However, they do still contain mercury, produce UV light, emit heat and still take a few minutes to achieve full luminosity.
In contrast, LED lighting has advanced by leaps and bounds in recent years. The biggest drawback is that LED tubes are still far more expensive than fluorescent lighting (as much as ten times the cost), but they give an impressive return on that investment: they light immediately, contain no mercury, produce no UV light, have better color rendition, emit about 70% fewer greenhouse gases, use about 30% of the power required for fluorescents and last about four times as long.
Another advantage of LED lighting is that it is far more focused. Whereas a lot of light from a fluorescent tube goes off in every direction and therefore wastes the output, an LED tube produces light in a 120° arc.
On the down side, LEDs work better in environments where the ambient temperature is below 104°F. And then there's the cost, as mentioned above.
Lamps
Putting aside refits and house design, homeowners' lighting decisions are based around plug-in lamps. In this arena there are two main considerations, both of which are gradually replacing the traditional incandescent bulb: LED and CFL.
Before we look at those, it's worth mentioning the $10 Million Light Bulb that you may have heard about. Back in 2007, Congress passed legislation that will gradually make the incandescent bulb illegal in the US – a very good and difficult step in forcing companies and consumers to move on from the cheap option and produce more efficient designs. As a softener, they offered a $10 Million prize to the first person who designed the next generation of bulb.
Five years later, they awarded the prize to the Phillips electronics company. But the next gen bulb isn't really what they wanted: it costs $50, it doesn't fit the requirements and it's not going to replace anything very much. It is an important step in the right direction but, unfortunately, the people who wrote the competition guidelines didn't know very much about energy efficient lighting.
More important technological advances – from the