All this talk about LEDs replacing incandescent lightbulbs isn't new. Just ask the man who invented the first practical semiconductor LED 50 years ago. Even then he predicted that LEDs would someday replace incandescents because they turn most of the electricity they use into light. Thomas Edison's invention has had a very long run, but his incandescent lightbulb converts only 10 percent of its electricity into light, releasing the rest as heat.
Working as a GE researcher in 1962, Dr. Nick Holonyak, Jr. discovered a red LED that laid the groundwork for other scientists to create brighter and different color LEDs over time. In the video, LED at 50: An illuminating history by the light's inventor, on the BBC website, you can hear Dr. Holonyak talk about his 50-year-old innovation and see why he believes that LEDs offer the promise of a whole new take on lighting.
The red LED "was just the beginning," says Holonyak in a feature from GE Reports commemorating his discovery. "I knew that it was a very powerful thing and that these materials would become a source of white light. I thought it might be a decade. Little did I realize that it would take much longer than that."
And that brings us to Consumer Reports lightbulb tests. It's not every day that you see products scoring 99 out of 100 in our Ratings. But LEDs have a lot going for them. Unlike CFLs, they brighten instantly even at frigid temperatures. Frequently turning them on and off doesn't affect performance and LEDs do not contain mercury. Of course, not all LEDs earned near perfect scores. We found others that weren't so terrific—dim bulbs, bulbs that give off a ghastly light, and bulbs that can't cast light in all directions.
And then there's the price. Most LEDs we tested cost $25 to $60 before rebates. But prices continue to drop and you're paying upfront to save money in the long run. Even at $25 the best LEDs can save you about $130 in energy costs and replacement bulbs over their 23-year life, compared with an incandescent. To find the best bulbs for your sockets, check the results of our tests of LEDs, CFLs and halogen lightbulbs.