There was a time not so long ago when just about every light in a house was an incandescent bulb. An incandescent bulb that drew 75 watts of power to put out about 630 lumens of light.
Then the CFDs (compact fluorescent discharge) became popular and affordable around 2000. CFDs vary a lot but on average a CFD that draws about 18 watts of power puts out about 600 to 620 lumens of light. So CFDs used about a quarter of the power and produced about the same amount of actual light. Also, in theory, CFDs lasted about five times longer than the ‘average’ incandescent bulb although I never found this to be true. My experience is that CFDs did not last as long incandescent bulbs.
Another problem with CFDs was that—being powered by fluorescent discharge—they flickered. They flickered really fast and 95 percent of people could not even notice it, but people sensitive to light flicker could pick up this very fast flickering.
The other thing some people did not like about CFDs was that they needed to warm up before they put out their full brightness. As they got better and better the warm up time got less and less, but even the latest of CFDs still have a little warm up time required.
But now we have the modern LED lights where with just 9 watts of power they put out 650 lumens (depending on the actually LED unit being used). Also they are instant on with full brightness. When these first started arriving on the market about five years ago they were $100+ per ‘bulb’ but now they are down to about $10 per bulb making them generally affordable. Also, from what I have read, the LED bulbs actually do have a long life of up to around 15,000 burn hours. So if they were used for eight hours a day for every day of the week you should easily get five years out of them.
So compared to the incandescent bulb in the mid-90s that drew 75 watts to produce 630 lumens of light we now have LED ‘bulbs’ that draw 9 watts to give out 650 lumens. This is about a tenth of the power consumed to provide the same light.
Over the last few months I have gradually changed all the long-use lights in my house over to LED. This spreads the $10 per light cost out over a more manageable period.
Now to watch my power bills plummet. Well that’s the plan anyway.