Scott Hanselman

Saving Money on Lighting the New House

November 15, '07 Comments [25] Posted in Musings
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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 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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Thursday, 15 November 2007 20:38:07 UTC
We did this when we first moved into our new home. It helped out a bit, and the new energy efficient washer and dryer did as well. We really didn't put numbers to it, because we didn't have a baseline to compare against in the house. We knew we were saving money though. Our next thought is to get some solar panels up on top of the roof to help reduce our electrical costs even more... :D
Thursday, 15 November 2007 20:38:59 UTC
I thought this was going to be a post about how the wind blew the roof off of your new home...

Congrats on HanselKinder #2, I don't remember reading about that announcement. Boy/Girl/IUnknown?
Thursday, 15 November 2007 20:42:07 UTC
We've kept baby #2 on the downlow, but now that it's any minute now, the cat is out of the bag.
Thursday, 15 November 2007 20:53:35 UTC
We've replaced about 1/3 of the bulbs in our house with CF. I think overall I've seen a 5-10% decrease in the electricity bill. It's only been 6 months though so I'm not confident in that assessment.
We haven't replaced them all though because there are lights in the house that are used so little (less than a hour a week average I'd guess) that it just didn't make sense to jump from the $60 or we spent on bulbs to $200 on bulbs. yes, they might end up lasting a lifetime but I've got standard incandescents in our 11 year old house I haven't replaced yet either. ;)
BTW, for the CF newbies, the only CF downfall you'll find is that while they come on immediately, they do take 30-60 seconds to reach full brightness. Scott describes perfectly the color spectrum available and that these don't look like "office" lights. In fact, I like the light color from our CFs better than most incandescents now. But, the 30 second warmup can be a bother when fumbling for a glass of water in the middle of the night.
Thursday, 15 November 2007 21:23:55 UTC
There's also something to be said for the amount of heat that you AREN'T putting into your house now. In Houston, this is a big deal, because all of that adds up and it's something that we have to make up for with Air Conditioning.

It would be much harder to calculate, but I bet it would be as significant a savings in reduced cooling bill.

(congrats on baby #2!)
Thursday, 15 November 2007 21:25:55 UTC
One thing to keep in mind, the "wasted" energy of an incandescent light is all heat. So the only time this is really wasted is in the summer when you have to pump this excess heat outside. I heat our house with oil and at the current oil prices I'm thinking a little extra electric heat is just the ticket. If I get some time I'll try and make a spreadsheet that factors that part of the equation in, or has someone already done this?

Thursday, 15 November 2007 21:44:30 UTC
Living in a climate where it's hot most of the year (Florida), one of the biggest advantages of CFL's for us is the relatively low amount of heat they produce. However, we've found that warm-up times and color "quality" vary greatly depending on the brand of bulb we use. There's been a couple of bulbs that claimed to be "natural", but looked anything but.

What brand of light bulbs did you end up getting for your house?
Thursday, 15 November 2007 22:01:36 UTC
I like seeing this comparison in a spreadsheet, but I'm not completely sold on the CF lighting. I've replaced many lights in my house with CF lights, but the color of the light really annoys me as well as the delay in turning on. Also, I've had several of the CF lights burn out on me after only a couple years rather than lasting 5-7 or whatever they're supposed to.

The time of year we need our lights on most is the winter, and in the winter the extra energy from the incandecent lights is heat. I really have no idea how big of effect this is on our heating bill, but I would be really interested if John puts together a spreadsheet.

The place I still use them is in the porch light, but I'm working on replacing the ones in the house with the GE reveal incandecent lights. Oh, and I can throw those in the garbage when they burn out rather than saving them to be recycled since they don't have mercury in them like CFLs.
Lance Fisher
Thursday, 15 November 2007 22:04:34 UTC
Yikes! You mean to tell me that the average person in your neighborhood (who isn't going to be replacing their bulbs) is spending on average of $1000 a year just in lighting?!

Don't get me wrong, I'm all for swapping out for CFL and have done it with some of the lights in my home. But the payback seems to me to be more on the order of two years. Maybe part of it is that our electricity is cheaper than yours. I think we are paying 8cents a kilowatt hour and your spreadsheet is based on 15.

Actually I have some empirical (albeit non-scientific) data to back that up. We are running about 60-70% incandescents still in our house. Our electric bill for December/January/February averaged $55/month. I picked those months because there is no A/C to skew the data and those months require double the lighting needs than the summer months (sunset at 5pm instead of 9pm). Of course included in that $55 is also the cost to run the refrigerator, 5 computers that are always on, TVs(not on that much), furnace blower, electric stove, etc. I wish I could break it out more, but I would guess that our lighting costs for 3000 square feet of finished space are way below the estimates for your house above.

Thanks for the post. Great food for thought.
Rick Arthur
Thursday, 15 November 2007 22:13:24 UTC
In regards to CFL's, when replacing do you keep the wattage the same or up the wattage to achieve the same "output" or is that just another fallacy?

Also congrats on the new mini Hanselman!
Hank Hepler
Thursday, 15 November 2007 22:52:59 UTC
I get my full spectrum compact florescent bulbs from Full Spectrum Solutions I've been very pleased not only with the service but with the selection and quality of the products they carry.

I didn't know you could get full spectrum bulbs from Home Depot. Last I checked in the Washington, D.C. Home Depot, they only had the standard mid-to-low end compact florescents. I wouldn't be surprised if Home Depot is more progressive in the pacific northwest.
Thursday, 15 November 2007 22:55:28 UTC
Also keep in mind that CF light bulbs contain mercury. Dropping and breaking one could contaminate your house.


Thursday, 15 November 2007 23:02:09 UTC
I switched to CFL several years ago and have found them to not last as long as advertised. I've been told this is due to turning them off and on; and that to get the advertised life they should be on a few hours at a time, i.e. don't cycle them to often since it decreases their life expectancy.

A downside to CFL is the inability to use dimmers. In my family/media room there are times I want full light and when watching movies I want dim lights, no can do with CFL so am using incandescent here.

It has always amused me that lights are measured in power consumption (Watts) rather than lumens (light output). You could crank up the burners on your stove to create lots of power consumption but the light output would be relatively low. Most U.S. packaging does list the lumens in the small print.

I'm looking forward to diode lights, they are currently expensive, but they will last forever (or nearly so).

Steve S
Thursday, 15 November 2007 23:22:55 UTC
@Steve S - They make dimmable CFLs now. They are more expensive because they have additional hardware to manage the voltages, but they are nice. I encourage you to check them out.

@Hank - There's some kind of informal conversions out there. I use Lumens rather than watts, so a 150W regular light is about 23W as a CFI, etc.

@Rick - Only if they keep 50+ lights running for 8 hours a day in their house. The spreadsheet uses some constants that should probably be toned down.
Thursday, 15 November 2007 23:24:09 UTC
LED bulbs for me, those CFL have enough mercury in them to pollute acres of land if not correctly disposed of.

Thursday, 15 November 2007 23:32:17 UTC
Got any brand suggestions? I have about 50% CFLs, but they annoy me because they start out dim and take about 30 seconds to come up to full bright. Others I've had a problem with buzzing. One even blew up. I want to like CFLs, but not if they annoy me to death or burn down my house.
Friday, 16 November 2007 02:15:15 UTC

I use 40W power with 9W CFL equivalent for the outside. They are on all night and those 9W are the lowest wattage I found. Looking forward to the LED lights when they become more ubiquitous.
Friday, 16 November 2007 02:47:51 UTC
CFLs have their advantages and disadvantages. You should weight up whether these are the way to go. For example, CFLs can have their lamp life SHORTENED by turning them on and off in short periods of time, they are made for being turned on and left on (therefore they aren't practical in places like a toilet/pantry etc.) Also CFLs do not recycle as easy as GLS lamps, GLS Lamps can be crushed up to a fine sand like substance and disposed of easy, but with the complexity of CFLs you need to pull them apart and recycle separately (the glass doesn't crush up like a GLS lamp either) and not to mention the amount of mercury inside them too.

If you are lighting you house, you should consult with your local retailer or lighting shop for what is the best method, and frequently re visit these places to stay up with the current trends and technology.

Also as a side note, LED seem to be the better style of light only when the price becomes more practical for the average home owner.
Friday, 16 November 2007 14:12:21 UTC
Congrats on upcoming baby #2! My wife and I just had our second, and things changed quite a bit. Our toddler (2 3/4 yrs) is SO playful and active that he wears us out. But now we also have an infant to watch over. Between the two of them we have had little time for anything else. We haven't even found time to use the Roomba to clean the living room, and that thing runs itself! :-)
Saturday, 17 November 2007 00:28:22 UTC
That's lame that the builder wasn't more accommodating. Our builder installed CFLs almost everywhere except for some very bright halogens in the bathrooms. I love not having to replace them.
Saturday, 17 November 2007 01:28:50 UTC
I love your posts on the new house....happy that you have moved in, but bummed that we won't get any blog posts about your experiences with building!

On CFL's...Scott above is correct about not cycling them on and off...can take years off of their life. You are better off to turn them on and then leave them on for a few hours than turn them on/off, on/off all day.

I will say that most of the reading and research I've done says that CFL's are just a stop-gap solution. The real solution may be LED's or a technology that hasn't been invented yet.

As long as they are disposed of correctly, I am all for CFL's. Great work!
Monday, 19 November 2007 18:37:28 UTC
speaking of using LED' is an article in the EE Times:
Monday, 19 November 2007 22:50:09 UTC
The dimmer thing is the kicker for me. I use dimmers on all my can incandescent lights in the house, and I rarely have the lights on full brightness. My incandescents have all lasted for over five years so far, and I haven't replaced a single one. I think dimming your lights can increase the life span of incandescents.

When I last looked at dimmable CFLs and supported dimmers, it was too expensive initially to justify the investment. Maybe that's changed though, I'll have to look into it.
Monday, 26 November 2007 05:12:42 UTC
I don't like CFLs since I grew up in this kind of light. I am using dimmers and motion sensors to minimize the consumption power. We also at my home turn off lights when no one is in the room.
Monday, 03 December 2007 03:24:50 UTC
what does everyone think about storage: buy a bunch of external drives and chain them to a usb hub into a machine or a sata raid enclosure or something of that sort. Im curious on what "the man" uses for his storage needs
william newsom
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Disclaimer: The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.