When you enter a dark room and flip a light switch, as long as something lights up you probably don't think too much about it. Well, yesterday I thought about it because one of the bulbs in the basement has started flickering and needs to be replaced. Thing is, that bulb is probably at least 15 years old, and not really a bulb at all. It's an early Compact Fluorescent Light (CFL).
I actually don't know how old it is. I got it and a whole bunch of CFL's just like it years ago. I was leaving work by the loading dock one day, and I found several dozen of them being thrown out! There was some problem with the light fixtures they were putting them in. In any case, I salvaged them, gave some away to people who wanted them, and took the rest home.
They're an early design. Instead of the spiral tube that's become common, this one has three parallel U-shaped tubes coming out of the base. According to the markings on the tube, it's a Philips Universal, SLS 23W, 120V, 60MHz, 325mA device made in Mexico. Assuming this web page is referring to the same CFL (SLS-23), they're priced at $3.00. Here's one on eBay with a picture, listed at $15.99.
I've had some of these CFL's burn out earlier; I have others out in the garage still going strong. They take a short warm up time to come to full brightness, and can get pretty warm if they've been on for a while, but they give decent light. Considering they were originally 'free', have lasted for years, and save on electricity, they've done really well by me. I haven't done a rigorous comparison, but I suspect they last longer than some of the newer CFL's out there - but that's just my impression. They certainly last longer than filament type incandescent bulbs.
This is just one person's experience; your mileage may vary. The even newer LED bulbs coming into use promise even better savings and performance without the problem of mercury fluorescent bulbs have. I haven't invested in any of those yet (aside from one or two strings of Christmas lights and in flashlights), but I will be willing to consider them. In the larger scheme of things it's not that big a deal by itself, but the cumulative effects from millions of people using these? Worth thinking about.