The answer to this question depends on your current lighting situation. Incandescent bulbs are still the most common and least efficient models available for lighting needs. They use most of the power they consume in the production of heat instead of light. Compact fluorescent bulbs (CFLs) and now LED lights are much more efficient in terms of their lighting and energy use capacity. The important figure to think about is the lumens per watt number. This basically shows the amount of light a bulb produces for a single unit of energy, the watt. A 100 watt incandescent bulb produces about 15 lumens per watt, whereas CFL bulbs run in the 40-60 range. LEDs are a large step above that, with current models at or slightly above CFL figures with the potential for greater efficiencies down the road.

If your home is currently outfitted with incandescent varieties, the best option at the moment is to upgrade to CFLs. It should be noted however that you might want to wait until the incandescents are on their last leg or go out completely. This prevents changing out perfectly good bulbs and creating more waste than is necessary. Compact fluorescent bulbs are more expensive than the typical incandescent, however they last over ten times as long and are much more efficient. Some areas even provide rebates, making them even more affordable.

The topic of LED lighting continues and it would be best to wait a little for the technology to improve. Certain applications like flashlights and path lighting are perfect and affordable with LED technology. Bulbs for living spaces however are expensive and generally not worth the trouble at the moment.