Lighting
The Navy has some background data from 2002 (also linked from Data) that shows Low Pressure Sodium generating well over 100 lumens / watt (183 for the biggest lamps). Lumens is the standard measure of the amount of light emitted from a bulb. Watts are what we pay for and incandescent lights consume a lot of watts (e.g. 100W) to make not so many lumens (e.g. 1700 or 17 lumens/watt). More lumens / watt is better so here are some better-than-incandescent options.
CFLs (~75 lumens/watt)
Sources & Advice
Disposal
- EPA fact sheet
- many lighting and hardware stores, such as IKEA and Home Depot, accept fluorescent bulbs for safe disposal
- lamprecyle.org has a state-by-state recycling contacts map
Analysis
Must [...] Identify the light color. (Qualified bulbs are available in designated correlated color temperatures (CCT): 2700K (warm white), 3000K (soft white), 3500K (white), 4100K (cool white), 5000K (natural), or 6500K (daylight). Provide a color rendering index (CRI) of 80 or more. Incandescent light bulbs have a CRI close to 100. (Learn about color rendering index and correlated color temperature.)
- thebulb.com's about page includes an explanation of color temperature:
Color Temperature
The color temperature of a light bulb can best be described as how the light compares to “natural” sunlight. Outdoor sunlight has a color temperature of around 5,500K. Bulbs with a higher color temperature (closer to 5,000K) will produce light that is more “cool” or blue. Bulbs with a lower color temperature will produce light that is more “warm” or yellow. The color temperature of a light bulb is usually described by how “white” a bulb is, like soft white, bright white, etc.
Description | Color Temperature |
“Warm white” or “Soft white” | < 2700 K |
“White”, “Bright White”, or “Medium White” | 2900 - 3000 K |
“Cool white” | 4000 K |
“Daylight” | > 5000 K |
Source: http://www.thebulb.com/store/t-compact-fluorescent-light-bulbs.aspx
LEDs
"The GS6 LED downlight has a system efficacy of up to 35 lumens per watt, which is comparable(??) to compact fluorescent downlights, and more than three times the efficacy of a bare 65W incandescent reflector lamp." This story indicates that portablelight.org's solar-powered LED lamp gets 80 lumens/watt. Take that, GS6.
Novelty
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