Starting in January, the common incandescent light bulb becomes illegal, well maybe, in most of the United States. (Some recalcitrant states, SC and TX to name two, seem hell bent on reminding the federal government of the long forgotten 10th Amendment to the U.S. Constitution, but wasn’t that fight settled a long time ago?) Advocates of this law say that it encourages the use of more energy efficient lighting sources such as CFL and LED lights. It has been noted that a large fraction of the energy consumed by an incandescent light bulb goes to create heat and not light, and that the newer, high tech devices produce an equal amount of light using less energy.
However, those of us who aren’t lucky enough to live in AZ, south FL, or San Diego, demand a LOT of heat many months of the year. In Montana, I use natural gas to heat my home about 7-8 months of the year. In South Carolina, I heat my home about 5-6 months of the year using wood and electricity, not every day, but most of them from November to April.
The energy that creates heat, not light, in a regular incandescent bulb is NOT wasted during those months. It is a nearly perfect substitute for the alternative heat in my home. The same electricity that heats the filament in my incandescent bulb in my living room in my South Carolina home in winter will be used by my heat pump to reproduce the heat lost when I convert to CFL or LED lights when my woodstove runs low. There is NO energy savings of any important degree. (It bears noting that my heat pump is a more efficient producer of energy than my incandescent bulbs, but that is not my main point as is explored more below.)
Of course in the spring, fall, and summer, the CFL bulbs will not be producing heat that I don’t want, but that isn’t my point here. I am only making the observation that you are foolish to think that you will get the savings printed on the carton of CFL light bulbs if you ever use gas, electricity, or any other energy source to heat your house. Replacing incandescent light bulbs with cooler CFL or LED lighting means that other heat sources have to work harder in your home when it is cold outside. Of this there can hardly be any doubt.
To be sure, heat pumps and natural gas may be more efficient heaters than incandescent bulbs, no argument here. I am only making the point that for homes in cool or cold climates, the promised energy savings simply cannot emerge.
It makes a lot more sense to use CFL or LED lighting outside where the incandescent light bulb heat is wasted, or during summer or non-heating months, and I use them myself in this application. I have made a little Excel spreadsheet calculator [XLS] that properly calculates the real energy savings you will get from switching to CFL or LED lights from incandescent which is based on the number of days that you think you heat your home. Those of you who are interested to see just how dishonest the current forecasts are are welcome to use this simple tool. [Read more…]