They're almost as energy efficient as LEDs but take at least 30 seconds to reach full brightness, don't last as long, and most aren't dimmable. Halogen bulbs ... 60-watt equivalents, the Utilitech ...

Best of all, just about every smart bulb on the market ... That includes standard 60-watt replacement LEDs, floodlights, weird-looking stick-shaped LEDs, dimmable LED bulbs and more.

produced by a given amount of electrical energy (watts). The more the lumens per watt the more efficient the bulb.