Saving Money on Lighting the New House
Our final move into the new house is this weekend. We did a three phase, three week move. First week - anything small not nailed down. Second week, medium-sized stuff...basically everything except a week's food. Third week, all furniture. This has allowed me to keep working and 9-month pregnant Wife to be relatively relaxed about the whole process.
Aside: If you're moving to Portland, or want to rent a house, let me know! I'll put a Craigslist listing up soon.
The new house is larger to accommodate a family of four as well as a guest room for overseas relatives and my home office. The builder put in incandescent lights in all fixtures, which was a bummer. I spent a few hours last weekend replacing all the lights with Compact Fluorescent (CFL) Lights.
There are usually three kinds/colors of these lights...it all depends on what their view of "white" is. We got natural-light (more blue-colored) full spectrum compact fluorescent to minimize that "office look." These are very natural-colored and produce a clean, crisp white that isn't depressing.
The total bill to replace every single light in the house was $205 from Home Depot. I saved up a bunch of coupons and waited for a 2 for 1 sale on some of these lights. Why spend so much on new lighting? Here's why, using a custom spreadsheet with some formulas from this very good article on lighting:
This spreadsheet shows EVERY light in the house that was replaced (all of them). There's "can lighting" in the ceiling in many cases, as well as closet lights, etc. This spreadsheet was originally aggressive, assuming each light was on 8 hours a day (usually from about 4pm to about midnight) when more realistically less than one half of them is on. Ideally each light would have a separate "hours on" number, so I put that they were all on 4 hours a day, which is more representative when averaged across all lights, but you get the idea and you're welcome to mess with the numbers.
(Yes, I realize that this table doesn't wrap well...sorry)
Location | # | LightHrs | OldW | Total | kW | Cost/Day | Cost/Mo | Cost/Year | NewW | Total | kW | Cost/Day | Cost/Mo | Cost/Year | Savings |
Downstairs | 27 | 108 | 60 | 6480 | 6.48 | $ 0.97 | $29.16 | $349.92 | 13 | 1404 | 1.40 | $ 0.21 | $6.32 | $75.82 | $274.10 |
Kitchen | 7 | 28 | 150 | 4200 | 4.2 | $ 0.63 | $18.90 | $226.80 | 23 | 644 | 0.64 | $ 0.10 | $2.90 | $34.78 | $192.02 |
Office | 4 | 16 | 100 | 1600 | 1.6 | $ 0.24 | $7.20 | $86.40 | 16 | 256 | 0.26 | $ 0.04 | $1.15 | $13.82 | $72.58 |
Upstairs | 18 | 72 | 60 | 4320 | 4.32 | $ 0.65 | $19.44 | $233.28 | 13 | 936 | 0.94 | $ 0.14 | $4.21 | $50.54 | $182.74 |
Outside | 5 | 20 | 75 | 1500 | 1.5 | $ 0.23 | $6.75 | $81.00 | 16 | 320 | 0.32 | $ 0.05 | $1.44 | $17.28 | $63.72 |
Misc | 6 | 24 | 60 | 1440 | 1.44 | $ 0.22 | $6.48 | $77.76 | 13 | 312 | 0.312 | $ 0.05 | $1.40 | $16.85 | $60.91 |
Total | 67 | 268 | 505 | 19540 | 19.54 | $ 2.93 | $87.93 | $1,055.16 | 94 | 3872 | 3.87 | $ 0.58 | $17.42 | $209.09 | $846.07 |
It's not a very controversial spreadsheet. Certainly when you replace a 120W light bulb with a 23W one and start adding multipliers like hours*lights*etc, you will save money. The only question left is when will you break even on the initial capital expenditure?
For us, our outlay was $200 and we'll recoup that easily within a quarter to half-year. That will multiple again, as in my personal experience CFIs will last 3-6 years. After almost exactly 5 years we just had 3 of 6 CFL lights in our kitchen all die within a week of each other. That's a lifetime of about 10,000 hours for me compared to a 1,000 hours for a standard light. My outlay of $200 will last ~5 years and I avoid replacing every light in the house at least 5, if not 10, times in that 5 year period.
We've kept the old bulbs and will either give them to relatives or save them for a rainy day. Unfortunately this builder wouldn't omit the bulbs which seemed a silly thoughtless thing to me.
About Scott
Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.



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