LED vs. Incandescent Light Bulbs
With new lighting regulations going into effect in 2012, the FTC did their part to help educate consumers by developing packaging standards for lighting manufacturers. Currently, consumers use watts to figure out what type of light bulb that they need to purchase. However, with new technologies coming onto the marketplace every day that consume less power, this unit of measurement is not really an accurate depiction of how much light a bulb is going to put out. Having terminology such as “60 watt equivalent” is helpful, but confusing at the same time because a consumer isn’t aware of the energy savings that they are getting from that light bulb. The new standards from the FTC will focus on lumens and not watts to help consumers determine what type of bulb they need to purchase. But, the big question is the difference between a watt and a lumen.
Let’s first start with the definition of a watt. A watt is defined as the power needed to move a one kilogram object at the speed of one meter per-second against a force of one newton. More simply put a watt is a measurement of how much electrical power a device consumes. When looking at lighting and watts, you are not looking at how much light a bulb puts out when looking at watts, but how much energy a bulb uses to put out that amount of light.
Now moving on to lumens, a lumen is a measurement of the amount of light that is contained in a certain area. The technical definition of a lumen is one candela multiplied by one steradian. A much simpler definition of a lumen would be that one lumen is equivalent to the amount of light put out by one birthday candle when you are standing one foot away from it. If a light bulb puts out 100 lumens, imagine standing one foot away from a cake with one hundred birthday candles on it.
Lumens are more accurate way of measuring the amount of light a particular bulb is putting out, because lumens are a direct measurement of light output. Wattage, even though it is what people have become accustomed to seeing on packaging and measuring how much light they are seeing, it is not really an accurate way to measure light output. Just because a light bulb uses a particular amount of energy to run, does not mean that it directly correlates with the amount of light that is put out. With a variety of energy efficient CFLs, LEDs and Halogen lamps coming onto the market on a regular basis that do not use nearly the same amount of energy as incandescent bulbs it makes sense for people to move away from thinking about wattage when they purchase a bulb and start thinking about lumens.
Source: http://blog.tcpi.com/2011/02/15/watts-vs-lumens-and-what-does-it-mean-to-me/
The table below shows the relationship of watts for incandescent bulbs and LED bulbs using lumens as the pivot point or commonality. If we look at the 60-watt incandescent bulb in the table, it produces 800 lumens. The equivalent 800 lumen bulb is a LED bulb consuming 13 to 15 watts (and falling - mine have been closer to 9.5 watts). As mentioned previously, swapping 60-watt incandescent for 60-watt LED, can lead to electricity savings of more than 75%. The best policy that the government to push is the LED light bulb.
The bottom chart shows how we compared to our energy efficient neighbors over the past several years. LED lighting replacement has made us much more energy efficient. I installed LEDs in three steps - each adhering to the $5 per bulb constraint. The first install was in areas that were heavily trafficked and had the least efficient lights. The kitchen, bathrooms and mud room were heavily trafficked. I also replaced the decorator lights (least efficient - the ones with 4 small bulbs each drawing 40 watts). The second install were all the outdoor lights. Many of these bulbs did not quite hit the $5 per bulb constraint, but were close and their impact was large. The last install the entire basement. Almost all of the flood lights were less than $5 per bulb. With the video game unit in the basement and Christmas vacation approaching, the video restriction is lifted during vactions. That means that the basement becomes heavily used. The pay back in savings is less than 24 months. It is less than that, when one waits for the LED light bulb sales and purchasing intelligently and placing them in high trafficked areas.
All data are verifiable by Xcel Energy and are reflected in our monthly statement.
