CFL vs LED: Which Are the Most Energy Efficient Light Bulbs?

As incandescent light bulbs were finally phased out altogether in 2014, the CFL vs LED debate took on new epic proportions. It still isn’t anywhere near being solved, which is why today we’re taking a look at the two contenders: Compact Fluorescent Lights (CFLs) versus Light Emitting Diodes (LEDs).

For those of us who have been around for some time, the debate in itself might seem odd. After all, it was just a decade or two ago that deciding on the type of bulb you need was simple. All you needed to do is figure out how much light you need, correlating brightness with wattage, and then picking up the bulbs at the nearest hardware store.

Today, things couldn’t be any more different—but that’s all for the better. Sure, these new, fancier types of lighting cost more, but they last far longer than any incandescent ever designed did. And prices are obviously going down: while LEDs cost around $100 when they first hit the market, Philips started selling them for as little as $5 in 2014.

cfl vs led vs incandescent wattage

Image source: Fine LED

So, wave goodbye to the trusty old incandescent light bulb. In 2014, they became nearly impossible to buy and by 2020 they actually won’t be in any store in the U.S. Hopefully, by then, you will have decided between the CFL and the LED.

To help you, we’re going to start you off by explaining how each of these bulb types work. We’ll be listing pros and cons for each, analyzing price points, lifespan, and environmental impact.

CFL vs LED bulbs: How do they work?

It’s simple to understand how an incandescent light bulb works. All you have to do is run electricity through a wire filament until it glows. That’s not how either LEDs and CFLs work, though.

CFL (Compact Fluorescent Light)

For a CFL to produce visible light, you have to run electric power through the tube they comprise. The argon gas and mercury vapor inside will react, thus producing UV (ultraviolet) light. This light will then become visible—but it’ll be a different type of light compared to the incandescents’ warm one.

CFL pros and cons


  • Price: at an average cost of $2, CFLs are only $1 more expensive than incandescents, and far cheaper than LEDs.
  • Energy efficiency: The CFL equivalent of a 60W incandescent only consumes 13-15W per bulb.
  • Even lighting: LEDs are essentially unidirectional (though omnidirectional designs are becoming available). CFLs can shine their warm light in all directions evenly.
  • Color temperature: CFLs manage to emulate the color spectrum of a traditional incandescent. They can produce both soft, warm light and cool, bright white tones, which replicate natural daylight.


  • Non-dimmable: Of late, dimmable CFLs, as well as dedicated CFL dimmers, are becoming available. However, the offer is still limited. Operating a CFL bulb with a standard dimmer can reduce bulb lifespan and also result in flickers, flashes, as well as other performance issues.
  • Don’t instantly light up: Although they don’t need to ‘warm up’ per se, CFLs do not turn on instantly. Some models can take from 30 seconds to 3 minutes to be completely turned on. For this reason, it’s wise not to turn them on and off repeatedly and to leave them on for at least 30 minutes at a time. Otherwise, their lifespan can be significantly reduced.
  • Pose a certain safety risk: CFLs contain mercury, which makes them be perceived as dangerous and toxic. Though the amount of mercury that a broken CFL bulb expels into the atmosphere is very small (0.01-0.7mg), it’s still wise to handle them with care. Mercury is, indeed, harmful for both people and the environment. Recycling CFLs can be difficult.
  • Cannot always be used outdoors: CFLs are best not used in extreme temperatures. They can become sensitive and their performance can be affected in temperatures below -10 degrees Fahrenheit and over 120 degrees Fahrenheit.

LED (Light Emitting Diode)

You’ve been using LEDs for ages, but not necessarily to light your home. Most electronic displays use tiny LEDs, which project a small, weak, unidirectional light. Up until a few years ago, most LEDs worked like this and omnidirectional designs were very expensive.

LEDs work simply by combining positive and negative electrical charges and creating energy. The diodes then release this energy as light.

led cfl incandescent energy efficiency lifespan

Image source: ORO Eco

LED pros and cons


  • Lifespan: LEDs are the longest lasting commercially available option for lighting. Consumer Reports state they can work for 20,000-50,000 hours, which is 5 times longer than any other type of light bulb. They can actually last you your whole life.
  • Energy efficiency: They’re the most efficient option, with only 6-8W per bulb, as estimated for the equivalent of a 60W typical incandescent bulb.
  • Instantly turned on: Unlike CFLs and other types of lamps, LEDs can instantly switch on and produce light. Turning them on and off repeatedly will have no negative impact on their lifespan and performance.
  • Highly durable: LEDs do not overheat. At 3.4 btu’s emitted per hour, they are almost 10 times as heat-proof as CFLs, and over 22 times better than incandescents. The cool off almost instantly and can be touched while in use. The glass the bulbs are made of is very sturdy and can withstand significant amounts of impact. They are also not sensitive to humidity, which does apply to CFLs.
  • Environmentally neutral: Unlike CFLs, they contain no toxic substance. Running 30 such bulbs at a time would produce 451lbs/yr of CO2 emissions (far lower than the incandescents’ 4,500lbs/yr and the CFLs’ 1,051lbs/yr).
  • Color range: They come in both soft and bright white hues.
  • Dimmable: This feature is available in some models.
  • Cheap to operate: Operating 30 bulbs each year would only use up 329KWh, amounting to a power bill of only $32.85. Compare this to incandescents (3,285KWh/yr and $328.59 spent on the power bill) and to CFLs (767KWh and $76.65, respectively).


  • Historically high-priced: When they first emerged onto the consumer market, a single LED bulb could cost as much as $50 to $100. This has changed: a 60W-equivalent LED bulb at IKEA now costs $5—but they’re not that easy to come by, especially if there’s no IKEA where you live. As of this writing, CFLs are still far cheaper and it doesn’t look like this is going to change any time soon.
  • Uneven directional light: Though progress has been made toward improving omnidirectional LED lamp designs, this is still an issue. LEDs might be great for linear lighting circuits, under-cabinet lighting, spotlights, office lamps, and such. However, for even lighting, CFLs are still the better option.

directional light recessed CFL vs LED light

Some argue unidirectional lighting might actually be a good thing.

Image source: My LED Lighting Guide

CFL vs LED: The verdict

Let’s be honest here: it’s all about the money. LEDs are more expensive upfront; however, it’s impossible not to acknowledge the fact that they last longer. Also, a broken CFL will cost more than an incandescent to replace, which doesn’t make them as economically viable as it may seem on first glance.

Then, LEDs do last longer and require less watts to run. So, while upfront costs may be higher, operational costs make them seem like very wise investments for the future. The chart below explains what these costs would be, at an average price of $0.12/KWh. The timeframe, 23 years, is an approximation of 25,000 hours of use, at a rate of 3 hours/day.

cfl led light bulbs cost comparison

Image source: The Simple Dollar

It’s obvious that buying a better quality lightbulb, with a longer lifespan, can save you some good money down the line. Compare the $201 required to keep a single incandescent fixture on for 23 years with the $48 for a CFL lamp and $38 for the LED lamp.

Aside from cost, there’s the issue of environmental impact. CFLs contain the toxic heavy metal mercury, are more likely than LEDs to need replacing (because of a shorter lifespan and lower durability), and also cost more to operate. They may be more environmentally friendly than incandescents, but, compared to LEDs, they emit more than twice as much CO2.

Given all of the above, it seems rather likely that CFLs also become obsolete down the road (some aren’t giving them much longer than another decade). So, the question then becomes: want to switch to LEDs now, or wait another 10 years to do it?

Of course, some argue that they prefer CFLs because they are better at replicating the light color spectrum of incandescents. The issue of even lighting also comes into play, as does the ease of replacing CFLs versus LEDs. Their base was designed to replicate that of incandescent bulbs, which means they require no special adaptor and can fit into just about any type of fixture.

Considering all this, you might be tempted to opt for a mix between CFL and LED lighting in your home. This might just be the best choice right now, with LEDs for reading lamps, kitchen spotlights, and décor highlighters and CFLs in the rest of the house.

In time, technology is sure to evolve and prices for newer designs and inventions are likely to continue decreasing. So, if you’re not entirely ready to decide on CFL vs LEDs yet (even though LEDs do look like the more future-proof choice), it’s ok. There’s still time.

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