Types | Terms | Links
See also Compact Fluorescent Lamp Bulbs (CFL) in environment,
LED lights in products and Light Bulb size/dimensions nomenclature here.

Types - Incandescent, Compact Fluorescent Lamp (CFL) and Light emitting diode (LED) Bulbs

Energy saving lamps have high luminous efficacy (more lumens per watt).

Comparison of 65 watt (700-900 lumens) equivalent bulbs. Nov 2013
3 hours/day = 1,000 hrs/yr for 10 years (10,000 hrs) with an electric rate of $0.10/kWh.

Type	Watts	Lumens	Life hrs	Cost (bulb)	Total Cost (10 yrs)1			Manufac- turing6 Energy (MJ)
					Bulbs	Elect	Total
Incandescent2	60	800- 900	1,000	$0.80	$8	$60	$68.00	10-106
Halogen	43	750	1,000
CFL3	15	900	8,500- 10,000	$1.25	$1.50	$15.00	$16.50	11-521
LED3	8-12	800	25,000	$12.00	$12.00	$12.50	$24.50	40-1,490
LED (2016)4	6-9	800	40,000	$65	$65	$5.80	$11.80	26-484

Note: If you compute over the lifetime of the LED (23 yrs) the cost CFLs and LEDs is about the same.

1. You will see things like $200 savings over the life of the bulb on the package.
   This is over an expected life of 23 years and uses a cost of electricity of 15¢/kWh
   It does not take into account the time value of money. 
   i.e. a savings of $5 in 23 years is not worth as much as $5 today.
2. Incandescent: Edison type bulb. - Tungsten
3. LED's were dimmable, CFL's here were not. (There are dimmable CFLs)
4. Efficacy is expected to increase to 202 lm/W by 2015 (DOE). *
5. Projections for LED costs per 1,000 lumens (klm) in 2015 range from $2.20 to $6 *
   See LEDs Magazine - LED fabrication roadmap targets  LED prices of $2.20/klm by 2015
   According to Strategies Unlimited, the average manufacturing cost per klm has declined
   from $13 in 2011 to less $3.65 in Sept. 2013
6. Manufacturing Energy - The DOE in the report below adds manufacturing and packaging
  energy use in order to compare life-cycle energy savings.
  The numbers are Mega Joules (MJ)/20 million lumen-hours, so since it takes 
  22 incandescent bulbs to match the life of 1 LED they use the energy for 1 bulb X 22.
  This is very small compared to the energy consumed in using the bulb which is:
  15,000 MJ/20 million lumen-hours for incandescent and 4,000 MJ/20M l-h for CFL and LEDs
Source: Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting | DOE 

Note: Other sources report life as: Incandescent = 2,000 hrs LEDs in electronics - 50,000 hrs LED household lighting bulbs - 25,000 hrs In August, 2013 Consumer Reports tested bulbs.
They looked at things like life, brightness, warm-up time, frequent on/off performance light distribution, efficiency, and color. In the general purpose 60 W equivalent category 6 out of 8 check rated bulbs were LEDs. In other categories 11 out of 15 check rated bulbs were LEDs. CFL's generally fell down in one of these categories: brightness, warm-up time, light distribution. Sample prices Nov. 2013 60W replacement bulbs

Type	Costco				Home Depot
	Price	Watts	lu	Dim7	Price	Watts	lu	Dim7
LED	$11	13.5	850	y	$13	12	800	y
CFL	$1.25	13	900	n	$1.75	14	800	n
CFL					$1	14	800	n

7. Dim = Dimmable There are advantages of LEDs over CFLs other than cost.
e.g. CFL's take longer to reach full brightness especially in the cold (even a 65° room).
CFL's contain mercury.
LED's on the other hand tend to be flat and directional.
LEDs contain lead, arsenic and a dozen other potentially dangerous substances.

Terms:

 A19 - Common household light bulb shape
 CRI - Color Rendering Index
 CCT - Correlated color temperature
 CW - Cool White - 4000-5000K
 DOE - Department of Energy
 E12 - Candelabra Screw
 E26 - Standard (Medium) screw
 Energy Star qualified - Energy star for other appliances has to do with energy efficiency.
      For LED bulbs in also includes as a number of performance related metrics such as
      light distribution, durability, lumen maintenance and color quality.
      See Why Energy Star LED light bulbs are a rare breed | GizMag.com
 G25 - Global bulb shape
 HID - High-intensity discharge lamp - Mercury-vapor, Metal-halide, Sodium-vapor lamps
 klm - 1,000 lumens
 kWh - KillaWatt-hour
 LCA - Life-Cycle Assessment
 LED - light-emitting diode
 L-70 - Life = Time taken for the brightness to fall to 70% of its original value.
 Lumen (lm) - Measure of light brightness
 MJ - Mega Joule = 0.27 kWh
 OLED - organic light-emitting diodes 
 PLED - polymer light-emitting diodes
 RoHS - Restriction of Hazardous Substances
 S-6 Miniature standard shape 
 ...
 S-14 Standard bulb shape and size [14/8 in or 1 3/4 in diameter]
 SSL - Solid State Lighting - LED, OLED or PLED
 WW - Warm White - 2700-3500K