The LED Lady: Thanks for asking this very important question which can help residents interested in saving energy, getting rid of Compact Fluorescents (CFL's) and do right for the planet. First of all yes this bulb gets an A++ and why is that here's the list of why:
1) Because it is made by CREE who got their start in the semiconductor industry and eventually turned towards LED. What makes them so appealing is they are an LED only company, rather than being a lighting company that is still manufacturing Incandescents or CFL's, CREE is 100% committed to LEDs.
2) It puts out 450 lumens for 40 watt comparison or 800 lumens for 60 watt comparison (see below for lumen explanation)
3) It only costs $13.97 for all those lumens and it has a CRI of 80. (See below for CRI explanation)
What you need to know is there is a major shift taking place in the lighting industry that has to do with the way we produce light. In the far away past it was with candles and wicks and now it has moved to semiconductors, electronics, diodes, metal and plastics. The key thing remains, what color of light do you wish to have and how much do you want where.
CCT- Color temperature. Lord Kelvin years ago heated up a black piece of metal called a black body and as the temperature grew hotter it went from bright orange to violet. So when you are in a restaurant you are likely sitting under a 2700K (Kelvin), which some like to think of as sunset or if you are in an office with lots of bright light you are probably sitting under a 5000K, which is like being outside in the middle of the day.
Lumen is the amount of light coming out of a light bulb and wattage refers to the amount of energy it consumes. However 60 watt light bulbs have been around for decades and we've come to know thenLumen is the amount of light coming out of a light bulb and wattage refers to the amount of energy it consumes. However 60 watt light bulbs have been around for decades and we've come to know then
Color Rendering Index: The sun is 100 CRI which means colors that appear under the sun or natural daylight no matter what time of day are their actual colors. Artificial light is always trying to achieve a number as close to 100 as possible. Hands down whenever I demo test an LED against an incandescent or fluorescent it always wins based on the true colors. Also, LEDs are all full spectrum.