Lighting is one of the largest areas of household energy consumption, accounting for 8 to 15% of a typical Australian home's energy budget. In response to rising energy prices, the government is gradually phasing out older, less energy-efficient incandescent light bulbs. Newer options include both compact fluorescent (CFL) and light-emitting diode (LED) bulbs.
If you want to replace your older bulbs with LED lights, it can be difficult to choose between the many different options available. Here are some important factors to keep in mind when choosing.
Incandescent lightbulbs have relatively short lifespans, often requiring replacement after no more than 1000 to 2000 hours of use. CFLs significantly improve on this, and LEDs last longer still. However, unlike other lightbulbs, LED lamps don't "burn out". Instead, they gradually emit less and less light.
Even though an LED light may advertise itself as having a lifespan in the tens of thousands of hours, it probably won't perform at full capacity for that entire length of time; after 50,000 hours of use, a typical LED lamp will only produce 70% of its original output. On the other hand, even if you treat advertised lifespans as a high estimate, LED lights outlast their CFL and incandescent counterparts by thousands of hours. A much more reliable indicator of lifespan is the guarantee offered by the manufacturer; a 2 to 3 year guarantee is recommended.
Because LED lights are relatively new to the market, many households find themselves in the position of switching over to LED light without a lot of experience with this type of lamp. This makes it particularly important to check each light's energy efficiency, measured in lumens per watt or lm/W. This number indicates the lamp's light output relative to the amount of energy it consumes. The higher the number, the more efficient the lamp. Some manufacturers claim that their lamps can produce up to 160 lm/W in lab conditions, but figures in the range of 40 to 50 lm/W are more common.
Unlike CFLs, LED lamps reach full brightness immediately. This makes them ideal lights for cupboards, sheds, bathrooms and other areas where they're not going to be on for long; under the same circumstances, a CFL may never fully warm up until it's turned off. This quality is hard to measure numerically, so be sure to test both LED and CFL fittings to see which is right for the purpose.