Types of Light Bulbs:
Standard Vs. Energy-Efficient

There are literally hundreds of types of light bulbs on the market ranging from 60-cent inefficient cheap-o's to state-of-the-art LEDs and everywhere in between.

This page will help you sort through the madness to understand your options and how they apply to your home...

• "ER" vs "PAR" for higher efficiency
• Standard Light Bulbs
• Energy-Efficient Light Bulbs
• Light Bulb Comparison

ER vs PAR: Available for All Types of Light Bulbs

Before we get into the details about the types of light bulbs available, let’s get some industry jargon out of the way… you'll find the terms on light bulbs from every category:

• Ellipsoidal reflectors (look for “ER” on the bulb’s packaging – i.e. “75 Watt ER30”) – reflector lamps use reflective surfaces to maximize the light produced. Ellipsoidal reflector lamps focus light down to a smaller area and are much more efficient than their parabolic aluminized counterparts. They are commonly used as flood lights outside of a home.
• Parabolic aluminized reflectors (look for “PAR” on the packaging) are the less efficient brother to the ellipsoidal reflector lamp, although their reflective properties make them much more efficient than standard bulbs. They broadcast light over a much wider area and are also usually used outside.

ER and PAR bulbs tend to be used in lights that illuminate a relatively large area such as a big room with high ceilings or an outside area. They are probably not appropriate for smaller applications such as common house lamps.

Before directly comparing the types of light bulbs, you need to understand and be able to identify what kind of lights fall under each category: standard and energy-efficient...

Standard Types of Light Bulbs: Incandescent Standard "A" Bulbs

Incandescent light bulbs are currently the most common and also the most inefficient bulbs on the market. They work by delivering an electric current to a tiny glowing coil of tungsten, and you'll find them in three types: standard A and the (not much) more efficient long-life A and tungsten halogen.

When possible, steer clear of standard A bulbs (pictured right). While they’re less expensive to buy, they’re much more expensive when you factor in how long they last and how much electricity they use.

Energy-Efficient Light Bulbs

• Incandescent light bulbs - Long-Life & Tungsten Halogen
• Fluorescent light bulbs
• High-intensity discharge
• Light-emitting diodes (LED)

Incandescent Long-Life A Bulbs & Tungsten Halogen Lamps

Even the “longer-life” standard A bulbs are far less efficient than the fluorescent and LED lights we’ll discuss in a moment, but they are more efficient than the Standard A bulbs.

Tungsten halogens (pictured right) are yet another step up in the incandescent category but are still still not as good as the types of light bulbs discussed below. However, they're probably the best you can do in the Incandescent class of bulbs.

Fluorescent Light Bulbs

Fluorescent light bulbs are the most commonly used form of energy saver light bulbs and come in three main varieties for the home (follow links to learn more):

• Standard & dimmable compact fluorescent light bulbs - most commonly used in and best equipped fluorescent bulb for home use (on a separate page)
• Fluorescent tubes (standard) (on a separate page)
• Circline fluorescent tubes (aka circular fluorescent bulb) (on a separate page)

High-Intensity Discharge (HID)

High-intensity discharge energy efficient light bulbs are one of the most efficient types of light bulbs available. Since they take so long to ramp up to full brightness, they usually only make sense for outdoor lighting or when they’ll be left on for a while.

Common applications include the lights used for sporting events, street lamps and car headlights.

There are three main types of HID light bulbs in use today: mercury vapor, metal halide and high-pressure sodium. Since the first two are primarily used in commercial or public applications, let’s focus on the third…

High-pressure Sodium Bulbs

In the home, the biggest use of high-pressure sodium bulbs is for indoor growing of vegetables, plants and flowers due to its high efficiency along with the plant-loving orange-red light they give off. However, high-pressure sodium bulbs are great for any outdoor lighting needs.

They are brighter than other types of light bulbs and so fewer should be needed, plus they use electricity the most efficiently. Most efficiently, that is, other than LEDs…

Dimmable Standard Household
Base 50 Watt Incandescent
Light Bulb Replacement
with a 6 Watt LED, Warm White

Light-Emitting Diodes (LED)

Light-emitting diodes, more commonly known as LED lights, are the most efficient bulbs on the market.

While they were plagued with problems in the past - not the least of which were their ridiculously high price tags - most issues have been resolved and their cost continues to drop precipitously. Long-term, it's now the best bulb for your buck.

See our Energy Saver Light Bulbs page for more information.

Comparison of the Types of Light Bulbs: Standard vs. Energy Saver Light Bulbs

The following chart compares the types of light bulbs used in the home in order of least efficient to most efficient.

In terms of cost, compare the cost per 100 hours burned instead of the cost of the bulb, being sure to take into account the amount of electricity wasted. The more electricity you waste, the higher your electric bill.

As you'll see in the chart below, at current prices, the most cost-effective energy saver light bulbs most widely available for home use (bolded in chart) before taking your electric bill into account rank as follows:

1. Compact fluorescent lamps (CFLs)
2. Long-life incandescents
3. LEDs

However, after factoring in the percentage of electricity wasted as heat, a new winner emerges...

1. LEDs
2. Compact fluorescent lamps (CFLs)
3. Long-life incandescents

Bulb category	Bulb type	Indoor, Outdoor or Both	Life (hours)	Cost per bulb*	Cost per 100 hours*	% of electricity “wasted” as heat
Incandescent	Standard and Long-Life A Bulbs	Both	750 to 2,500	$0.60	$0.05	90%
Incandescent	Reflector Ellipsoidal or Parabolic Aluminized	Outdoor	2,000 to 3,000	$5.00	$0.17	90%
Incandescent	Tungsten halogen	Both	2,000 to 4,000	$7.00	$0.03	90%
Fluorescent	Compact fluorescent lamp (CFL)	Mostly Indoor (due to required temperature range)	10,000	$3.40	$0.01	80%
Fluorescent	Fluorescent tube, Straight tube or Circline	Indoor	7,000 to 24,000 (12,000 for circular tubes)	$7.50	$0.03	80%
High-Intensity Discharge	High-pressure sodium	Outdoor	16,000 to 24,000	$17.00	$0.07	50%
Light-Emitting Diode (LED)	Cool white/ daylight, Warm white/soft white, Super bright/high power	Indoor & Outdoor	35,000 to 50,000	$30.00	$0.06	Almost none
*Assumes 60 Watt incandescent equivalent (non-dimmable) and maximum hours in each bulb type's life range (n/a for high intensity discharge bulbs). Energy saver light bulbs most widely available for home use have been bolded.

As the price of LED energy saver light bulbs continues to drop, your combined savings for making the switch will be even greater.

See our Energy-Efficient Light Bulbs page for more information, including which bulbs to purchase for various home applications indoors and outside your home.

Also see...

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Incandescent bulb image licensed via Creative Commons Attribution-Share Alike 3.0 Unported license.

*Minimum Savings amount is average for the United States calculated over the life of the average U.S. home and assumes that you apply all recommendations on this page. Actual savings could vary based on region-specific factors.