Amidst much media buzz about efficient new lighting technologies and a general uproar about government light bulb "bans" worldwide, the most fundamental rule for saving energy on lighting seems to be fading: Make only as much of the right kind of light as you need, and shine it only where you need it. That's the key to saving money on your lighting bill.
No single lighting technology is the best for all situations, and the oft-touted "efficiency" ratings of more recent, high-tech lamps don't tell the whole story. Even the lowly, cheap and shamed incandescent lamp can be the best and most economical choice in some situations.
I've been living off the grid, 11 miles from the nearest power pole, since 1991. That certainly tilts my bias toward using the most efficient lighting technology available, everywhere in my home. But what I actually have is a mix of all the available technologies: incandescent, compact fluorescent (CFL), fluorescent (FL) and light-emitting diode (LED). Why? Let's start with lighting fixtures (called "luminaries" and a variety of other terms in the lighting business).
Choose your fixtures wisely
Hang any lamp from your ceiling with no fixture, and hit the switch. Where does the light go? A lot of it shines right on the ceiling, to illuminate your local spider's bug buffet. If the ceiling is painted white, a small bit of it will reflect back down to where you need it. Now install that same lamp inside a reflective fixture. Aha! All of a sudden, the light level in your room has increased with no increase in your energy use.
Keep in mind that your great-grandmother knew this too -- that's why she stuck a mirror or reflective metal plate behind her kerosene lamps. "Decorative" has nothing to do with practicality or electric bills if the fixture is shining light where you don't need it. The exception to this reflector rule is LED lamps, which by their nature cast light directionally. That's one of the advances that helped this expensive (but efficient) technology grab an early market share, as an under-cabinet light in a kitchen, for example.
Compact fluorescent lamps
CFL lamps have become very inexpensive lately, and seem to be the new standard for everyone who wants to be "green." Websites and pushy friends imply that if you don't replace every lamp in your house with a CFL, you might as well start driving a giant gas-guzzling SUV, and dump your garbage in the river instead of recycling. But in many real-world situations, CFL lamps are a terrible choice.
First, they don't like to be turned on and off repeatedly, unless they get the chance to warm up. If not allowed to run for at least 15 minutes with every use (30 minutes is even better), CFL lifespan will be shortened from what's estimated on the package. This presents problems in rooms where short visits are the norm, such as the bathroom (exception: if you have one or more teenage girls living in your house, 30 minutes and even more can be very common).
CFL lifespan is also greatly reduced by heat buildup inside fixtures. Most houses were wired with incandescent lamps in mind -- they are not harmed by heat -- and your fixtures may lack the ventilation needed for larger CFL lamps. Recessed ceiling fixtures are a particular problem, as are enclosed bathroom fixtures intended to keep humidity out. Some CFLs are designed to resist hot temperatures, but that may not be clearly labeled on the package. Do your homework, and Google is your friend.
Fortunately, most of the other "problems" with CFL lamps that are so widely publicized by folks enraged by the light bulb "ban" are at worst minor issues. Lifespans shorter than advertised and light not as bright as the incandescent "equivalent" printed on the CFL package are common complaints, but these are almost always due to a poor choice of fixtures for a room. Dimmable CFLs for the living room and outdoor CFLs for cold climates are now common, flicker has been eliminated with electronic ballasts, warm-up times have been reduced or eliminated in most applications, and the lamps are now available in a variety of color temperatures, mostly solving the five top complaints about the quality of CFL light.
Mercury in CFLs is often hyped by nay-sayers as a major environmental problem, but the amount of mercury in a CFL is actually minuscule -- a coal-fired power plant would release almost twice as mercury into the atmosphere to power an incandescent bulb over its lifetime than a CFL even contains. Also, both streetlights and the ubiquitous fluorescent tube lamps that illuminate almost every city, office, warehouse, factory, airport and garage worldwide also contain mercury, but the anti-CFL crowd seems to conveniently forget that fact. If you are faced with a broken FL or CFL of any kind, just don't lick your fingers after sweeping up the broken glass and phosphor powder with your bare hands. You weren't really going to do that anyway, were you? Use a broom, and follow a few simple directions.
There is no doubt that solid-state LEDs are the future of energy-efficient lighting, but right now they are no panacea. Press releases and news stories about exciting new LED technology that squeezes more lumens out of every watt pile up in my inbox each week, but most of them leave out one critical fact: It takes years for new LED technology to make it out of the laboratory, through UL, CE, CSA and Energy Star certification, be adopted by lamp manufacturers, and only then finally appear on the shelves at Home Depot. Right now, the LED lamps available to consumers for home use are just about as efficient as CFL and FL lamps, with some a bit lower and some a bit higher.
Heat buildup in fixtures shortens LED lifespan just like it does to CFLs, and current pricing on LED lamps is very prohibitive, though I am now testing a couple in my home that were under $20. Large LED lamps -- for example, those large enough to illuminate a kitchen or living room -- are still priced at $50 and up. Ouch! But prices will come down in the near future, just like they did with CFLs. Also, LEDs contain no mercury, have a very long life in the right fixture, and are very durable.
Fortunately, incandescents have not really been "banned" in the U.S.; it's more accurate to describe the new regulations as similar to CAFE standards for vehicles. You can already buy lamps that comply with the new standards for about $1.50 at Home Depot -- a far cry from 25 cents for the old type, I admit -- but the new bulbs are more efficient, and last longer. Over the life of the bulb, your energy savings will usually make up for the extra cost. Incandescents remain an excellent and economical choice for any part of your house that is used infrequently and for short periods of time, and in small fixtures where heat buildup causes problems with CFLs.
- Use CFLs to illuminate large rooms where the lights usually stay on for more than 30 minutes with each use. In my house, that includes the living room, kitchen, home office and bedrooms.
- If you have a problem fixture that wastes light where you don't need it or experiences lamp-killing heat buildup, consider replacing it with one that's designed to stay cool for CFLs and LEDs. Most fixtures are not particularly expensive, and the procedure is not usually difficult for a do-it-yourselfer. An electrician can replace most fixtures in about an hour. If this is a large light that you use frequently, your electricity savings could pay for the fixture replacement in a couple of years.
- Use incandescent lights in difficult areas where the lamp only stays on for a few minutes with each use, or where temperatures are unusually hot or cold. In my house, that's the bathroom, the mud room, and the outdoor lights. If you keep your porch light on for hours after dark, just get a CFL that's rated for outdoor use.
- Don't blow your entire paycheck on a shopping cart full of CFLs and LEDs at the hardware store. Different brands and models give different color, quality and patterns of light, and the "equivalent" ratings on the packaging, comparing them to traditional incandescents, are very subjective. Buy a few single samples until you decide what you like the best in different rooms and fixtures.
- Closets and storage rooms that you use only rarely and for short periods of time are perfect places to use up that carton of old incandescent bulbs that is likely gathering dust on a shelf somewhere.
- Anywhere you need very bright light, such as garages, workshops and even large kitchens, you can't go wrong with economical and efficient FL tubes.
- For under-counter lighting, desk lighting and reading lights, LEDs are the way to go because of their directional nature. Because the light is close to what you need illuminated, the size can be very small, and the cost quite low. My under-counter lights are currently small FL tubes, but the ballasts are failing (19 years old), and I'll replace them with LEDs when they die.
- Stick with name-brand lamps that are Energy Star rated and UL listed. Some imported "dollar store" CFLs are neither, and are so shoddily made as to be a fire hazard.