When you build a house, you find yourself in the market for a lot of light bulbs.
Prepare to be blinded by the light, because the range of bulbs on the market is both dazzling and disappointing.
According to the U.S. Lighting Energy Policy website, incandescent bulbs still account for about 85% of today’s household illumination. But the electric light bulb, as we have known it has not changed substantially since Thomas Edison’s invention, and these old incandescent are sucking up way too much power per lumen (the standard unit for the amount of light cast).
To produce light, incandescent light bulbs convert heat to light. The conversion requires a filament to be heated to high temperature, typically > 3000° K. Incandescent lamps have a low luminous efficiency, 10-22 lumens per watt, and a short average operating life of just 750–2500 hours. They may be the least expensive bulbs to buy, but their relative inefficiency and short lifespans make them more expensive to operate than other lighting options.
These old energy hogs are being phased out and replaced with more efficient lighting options all over the world. Here in the U.S., energy efficiency legislation was adopted by Congress and signed by former President George W. Bush in 2007. Last year, the government pulled the plug on the 100 watt incandescent bulb, and starting January 1st, the 75 watt incandescent bulb will soon be phased out. Retailers can continue to sell their remaining stock, but they can’t add more.
Under the federal law, screw-in based bulbs are required to use on average, at least 27% less energy by 2014, which means the 60 and 40 watt incandescent bulbs will be the next ones to go.
But we don’t need to wait until 2014.
If we have any hopes of reducing our carbon footprint, it doesn’t get any easier than switching out our light bulbs.
So what should you switch to today?
The options are daunting.
If you’re like Doug and me, you may have appreciated the ability to dim bulbs down from their brightest illumination to a more muted level at the end of the evening.
We think dimming is great for ambiance, but it turns out to be an incredibly inefficient use of incandescent bulbs. While you can dial down the number of lumens with a standard dimmer switch, the wattage (or unit of power used) does not drop proportionally. When you dim an incandescent bulb to half its brightness, you’re still using 80% of the full wattage. The more you dim, the less bang for your already sky-high incandescent lighting buck.
Enter compact fluorescent bulbs (CFLs)
CFLs have come a long way!
Fluorescent lighting converts ultraviolet light to visible light. In order to produce ultraviolet light, electrons flow through a fluorescent lamp and collide with mercury atoms. The collision causes photons of UV light to be released; the UV light is then converted to visible light as it passes through the phosphor coating in the glass tube.
The conversion process for fluorescent lighting is more efficient than the incandescent process, resulting in 75% reduction of the total energy consumed and a 10,000 hour typical lifetime.
Older generation CFLs used to cast a harsh, unflattering light, but improvements in technology have yielded fluorescent lamps with color temperature and color rendition comparable to incandescent lighting. Also, older generation fluorescent bulbs used to have to think about it for a second before they started to shine, and they tended to be sized much longer than corresponding incandescent bulbs, so they did not fit nicely into conventional lamps.
But these problems have been solved. You can now get instant-on CFLs that put out a warm, light from a compact device. While they cost a good bit more than incandescents, they last much longer. All this while using just a quarter of the watts for the same brightness of an incandescent bulb.
The energy savings is so big that a high-use fluorescent bulb that is kept on for an average of 5 hours per day will save you more than $8.00 per year on your electric bill if it is replacing an equivalently bright 60 watt incandescent. Since you can buy these CFLs for about $1.00 a piece these days, it’s just a matter of months before the purchase to pay for itself.
So, what’s not to like about a CFL?
For one, they all contain mercury, which is a hazard to our health and that of the environment. And because they are still relatively new, and they last a long time, the jury is still out on how that mercury is going to get dispersed as more and more of these bulbs find their way to the landfill.
Also, from a usage point of view, they are not dimmer friendly! They don’t dim smoothly and they don’t dim much. And if you turn them too low, they start to flicker annoyingly. While they do decrease in wattage almost proportionally to the amount the light is dimmed, from what we’ve read and what we are told by people who have tried them,dimmable CFLs don’t last nearly as long as advertised.
Standard, non-dimming CFLs have gotten a seal of approval from organizations like Focus on Energy who are now helping to subsidize their cost. So while they are still more expensive than equivalently bright incandescents at the checkout counter, it’s fairly easy to justify their purchase when you factor in the energy savings that will build up in a reasonably short time frame.
WHAT ABOUT LEDs?
Light Emitting Diode bulbs (LEDs) have a number of technical advantages. LEDs are the gizmos that have been around for years lighting up digital clocks and calculators. They produce the glowing red light that indicates our TV and other electronic devices are on.
LEDs use semiconductors that emit light when electrons move around. More recent innovation has allowed engineers to make them white and bright enough for light bulbs. They transform the light bulb into a rugged gadget that can withstand mishandling and accidental damage much better than either incandescent or compact fluorescents. You can put away your kid gloves when handling LEDs.
Not only do they lower the power consumption per lumen even further than CFLs, they also run significantly cooler to the touch, which can be a safety as well as a comfort advantage. Have you ever burned your fingers trying to remove a recently-lit incandescent light bulb? While CFLs emit about a third the amount of heat relative to the equivalent incandescent, LEDs emit only 5% as much.
Unfortunately, while LEDs are capable of dimming
they don’t seem to dim nearly as nicely as our warm old friend the incandescent bulb. We are finding that a conventional wall-mounted dimmer will start to lower the light output from a dimmable LED, but by the time you have turned the dimmer half way down, the light goes completely out very abruptly. It’s annoying. There doesn’t seem to be any low end dimming capability.
There is some good news here. When you successfully dim an LED light bulb down to its minimum of perhaps half of its full output of light, you also use only half the watts to produce that light. That’s a feature that incandescents can’t come close to matching.
The elephant in the room with LEDs is their high price tag. These puppies can cost 50 times what an incandescent bulb does. The cost of one LED may exceed the cost of screwing an incandescent bulb into every fixture in our entire house. We figure we’ll use 48 bulbs to light every room, closet and outdoor socket.
Initially we were planning to install dimmers in 10 of our light switches, but as we have researched what bulbs are available to us, we decided that all things considered, we are going to go with mostly low wattage, non-dimming CFL bulbs in our new house.
There are 3 lights though, that will hang from the ceiling of our main room that we are still determined to dim. In those spots, we intend to install an LED bulb. And while the initial cost will be pretty high, these three fixtures will be turned on more than most of the others in our house.
Assuming that one of these high-use LED bulbs is kept on for an average of 5 hours per day, it’ll save us perhaps $10.00 per year on our electric bill if it is replacing an equivalently bright 60 watt incandescent. So the payback should still occur within a few years, and we’ll really enjoy the ability to choose the brightness level in our main room fixtures.
How are you lighting your world these days?
How do you balance all these new choices?