Compact Fluorescent Project - Part 1: Economics
Just the other day my wife happened to be watching an "Oprah" episode where a Hollywood-type was pitching energy conservation to save the earth "before its too late", in an almost breathless manner. I am more likely to laugh and point at such drama than to stop and listen, but I had been thinking about converting many of the lights in the house to Compact Fluorescent (CF) bulbs. I hadn't spent much time thinking about it in earnest, nor had I done the analysis to figure out whether it made sense. Consequently I decided to do it as a project and fully analyze and optimize along the way, for your viewing pleasure.
I approached this project with two goals in mind. First, it should save me real money, not penny's here and there. Secondly, I should be able to have my quality of life impacted atleast neutrally, and hopefully positively, by the results. At the outset I had a hunch that it would be economical, but any quality of life improvements would only be a result of not spending as much money.
My first task was to assess how many potential incandescent bulbs that I could replace and what their average usage was so that I could calculate whether it would make economic sense to replace a particular bulb. One aspect of our household that makes this project easier is that we have quite a number of lights that are on timers and thus go on and off automatically. This practice makes it very easy to determine how many hours specific lights are on and thus accurately figure monetary effects. I factored in seasonal shifts for the outdoor lights that we would obviously change according to dusk and dawn, given that the difference between minimum and maximum daylight in our area is about eight hours. I discovered that there are quite a few lights that are rarely turned on and it didn't make sense to invest in replacing those.
It hadn't really occurred to me before, but we already have quite a bit of fluorescent lighting in our house. The original owner of this home was a facilities engineer and surprisingly used it in a couple of places. The master dressing area, the laundry room, and the guest room are all lit with the traditional 4 foot commercial fluorescent bulbs, for a total of 14 bulbs. For the dressing area I had replaced the standard bulbs with natural light versions for light quality reasons. In addition to the what we found in the house when we moved in, we have installed further fluorescent lighting for a variety of reasons. For instance, we installed a CF fixture in our son's room, not for economics reasons, but because we liked the fixture and it was very low profile so the room looked taller. We also installed fixtures that used the thin, short fluorescent bulbs under our cabinets that were also low profile and gave off very little heat which would be transferred into the cabinets above.
Our outside light fixtures, which I figured would be likely candidates for big savings, all have two heads. For a long time we have had only one of the lamps is occupied with a functioning light, as having two was overkill and just doubled the pleasure of replacing burnt out bulbs. This made it easy for me to replace the bulbs with their CF counterparts. I would move the working incandescent light to the non-functioning lamp, leave it unscrewed, and that would provide a nice backup or extra souce of light if we needed additional light temporarily.
Once I had figured out how many of the bulbs in the house that I was going to replace I started shopping. I targeted the bulbs that I thought would have the biggest impact, both in terms of economics and quality, like my office. I also wanted to focus initially on bulbs that we would be dealing with frequently so that I could experience the different bulbs and make subjective assessments about aspects like light quality and how many lumens are "enough" in the different areas. Over a week period I made several trips to Home Depot, Menards, and Target to acquire the bulbs. Their selections were quite different and allowed me to pick specific bulbs for different needs that I ran across. There wasn't much difference in pricing between the stores. I did come to hate the stupid clamshell packaging around the bulbs that unceremoniously drew blood on a couple of occasions.
As I was thinking about the economic impact of the project, rather than just considering the energy that they consume, I need to mention the cost of the bulbs themselves. When considering the ultimate expense of the new bulbs, it must be said that I frequently use good full spectrum bulbs and that are more expensive than normal bulbs. Consequently CF bulbs aren't that much more expensive than the bulbs I normally use. If I used crappy standard incandescent bulbs, the price difference would have been dramatically more. I guess I am either more sensitive to light quality, or perhaps I am just picky.
In the table above, the economics of the CF bulbs are pretty clear in many cases. With energy break-even point median value of under one year, you can get your savings right away.