How-to: make sense of energy efficient bulbs

After tinkering with finding the best light bulbs in our house last week, it occurred to me that while everyone keeps saying, “Florescent is better,” none of us really knows why.  I know that Martin has tried explaining it to me at least a dozen times, and even Martha Stewart broached the subject of compact florescent light bulbs (CFLs).  My eyes glazed right over every time.  I’m willing to bet that yours have, too.

With the cost of power in Germany and my love affair with this new light I picked up for only twenty smackaroos, I decided to sit down and actually LISTEN to my husband.  So here it is, at your disposal: the basics of light bulbs in plain, artsy-girl understanding.

The shindig on light bulbs

Two factors come into play in every light bulb:

  1. color temperature: known as white balance
  2. light output per unit of electricity: measured in lumens per watt

Hold on!  Don’t let those eyes glaze up yet.  My poetry-loving self actually LIKED learning this, and I think you will, too.

White balance

Did you ever go to those pioneer day events and see the black smith?  He’d be heating pieces of iron until they were so hot they began glowing a bright yellowy red.  The metal was heated to the point where it actually emited light.  His fire couldn’t generate enough heat for the next phase of light.  But if it could, you would have seen that iron turn white and then blue from the heat.

The color coming from our old, incandescent light bulb is the same.  Yellower light in your bulbs comes from 2700 Kelvin (2,400 degrees C), and whiter light comes from hotter temperatures around 4000 Kelvin (3,700 degrees C).  We’ve gotten used to that mellow yellow light that regular old bulbs produce, so now that we’ve got fancy, energy-efficient light bulbs producing the white, natural light, it doesn’t feel natural at all.

Lumens per watt (lm/w if you want to sound über fancy)

All I could think about here was my old Easy Bake Oven.  Did it ever strike you as odd that the whole idea behind those things was using a product (a light bulb) for something it wasn’t even designed for (heat)?

The energy going into a light bulb is turned into one of two things: heat or light.  You probably don’t turn on the lights in your house for heat.  Unfortunately, our old bulbs are really good at producing heat, burning Easy Bake cakes, and creating yellow light; florescent bulbs are not – much more of the energy they use goes toward creating whiter light.  Still, florescent bulbs create a little heat (things aren’t perfect yet, you know).

Using the exact same amount of electricity, a basic bulb creates 14-16 lumens (i.e. it ain’t good at it’s job).  A compact florescent pumps out 45-100 lumens.  (Huh?)  That all means that a compact florescent bulb cranks out 4+ times as much light with the same amount of electricity.  Less electricity for heat = more electricity for light.

How does it all work?

Our old, incandescent bulbs heat a metal filament that begins to glow from the heat.  That intense heat, which is over half of the temperature of the sun’s surface, eventually weakens some of the filament.  It dissolves.  Electricity can’t flow.  Our bulb is dead.  It’s like a pot of water:  it’s going to evaporate much faster when you boil it.  That’s why these bulbs aren’t known for a long life.

But what about these new-fangled florescent and energy efficient bulbs?  They’re using some major physics tricks that are way over this girl’s head to produce white light without the intense temperatures required in old incandescent bulbs.  The result is a bulb that lasts loooooonger because it’s not depending on a weak filament.  Some even have elaborate chips that essentially make the bulbs last a lifetime.  Florescent bulbs last 10x as long as incandescents.  You can turn them on and off 100,000 times, and they’ll still be kicking. Here’s the bulb I found for my lamp, so you can see they come in all sorts of shapes and sizes to accommodate different fixtures.

What to shop for?

To make things easier, most florescent bulbs are labeled “equal to 40 watt”, “equivalent of 90 watt”, etc. because those are terms we can understand.  The bigger the number, the brighter the bulb.  Except as you know, florescent lights don’t need nearly that much energy to produce the light.

Take the bulb I just bought for my new lamp.  It creates as much light as a 40 watt incandescent bulb.  But it doesn’t create all that wasted heat, so it only uses 7 watts of electricity.  I don’t burn myself when I bump into it, either.  Pretty cool, huh?

The only catch with florescent lights

  • They take a little longer to reach their maximum light output.  I really don’t understand why magazines say to experiment with this new technology in places like your closet.  Closets are an on-off kind of place.  You don’t keep closet lights on for hours (do you?).  At our house, we chose the most scientific bulbs (like the ones with those elaborate chips) for places like our living room where we leave the light on for long periods of time.
  • They cost more upfront.  Check out this super-quick Google calculator to see how much money you’ll save on power bills in the US by updating your bulbs (hint: it’s $6 a bulb every year).  The saved energy bills mean the bulbs pay for themselves, so I really don’t know if we can call this a catch.

To us, it only makes sense to invest a little more money upfront and buy florescent bulbs.  But that’s just us, and we wanted you to know what goes into making this home.

As one last note to wrap things up, bulbs that use less energy = less pollution if you’re getting your energy from coal and other non-renewable sources.  How’s that for a cool way to get a little greener?  Get better bulbs; keep our planet a little cleaner; save a few bucks along the way!

Here’s to a greener, brighter life from our home to yours.

Want more green tips that can save some dough?  Check out our guide to lowering your utility bills and 5 easy ways we pinch pennies and cut down on trash.

(Images for Making This Home)