Jul 12 2007
09:53 am

Just got our first full month electric bill since switching out our most frequently used light bulbs with CFLs (6 bulbs).

Along with other conservation measures, it looks like we had about a 15% savings compared to the same period last year, which for us works out to about $26 for a 30 day billing period at the current rates.

So basically, the CFLs have already paid for themselves (which doesn't seem possible, but there you go). Our savings may be higher because we work mostly from home so we are here 7X24 so our lights are on longer. Your mileage may vary.

It should also be noted that the average daily high temperature for June 2007 was about 2 degrees higher (88.5) as compared to June 2006 (86.6), so it's likely we ran the AC a little more this year than last.

R. Neal's picture

Doing some rough

Doing some rough calculations on emissions, it appears this represents the following reductions:

3.35 tons/year carbon emissions
6.48 lbs/year nitrogen oxide emissions
22.08 lbs/year sulfur dioxide emissions
99.36 mg/year mercury emissions

Based on these assumptions:

360kwh monthly savings X 12
1.55 lbs/kwh CO2 emissions
.0015 lbs/kwh NOX emissions
.00511 lbs/kwh SO2 emissions
.023 mg/kwh mercury emissions

This is based on the current month's savings * 12 months. Don't know what the real total annual reduction will be until after tracking for a full year.

Any of you people good at math please check my numbers. These emissions per kwh were randomly googled, so if any of you TVA types can provide more accurate emissions averages that would be great.

Bill Lyons's picture

Similiar experience

I have changed out every light bulb I can get to that is not dimmable in my house and have noticed significant savings as well. There are too many variables for any kind of pre-post comparison but the reduction in use is dramatic. I think I have replaced well over 25 bulbs, including lamps. The biggest offenders by far are the spotlight bulbs in the ceiling. Somebody who designs houses sure likes them. In my den – kitchen area alone I had ten of these, each at either 65 or 75 watts. I have six more in the master bedroom. Replacing them with 65 watt equivalent CFL’s makes a huge difference, and not just in the direct reduction of electricity used but also in the reduction of heat generated that the AC has to work overtime to eliminate. Just touching the incandescents after a couple of minutes of use reveals their true nature as mini-furnaces. Sure you could flip that in the winter but the entire HVAC equation would add significant overall savings.

R. Neal's picture

Bill, there are dimmable

Bill, there are dimmable CFLs now, but they are a lot more expensive and a lot harder to find.

These guys have just about every kind of CFL made:


I got a couple of dimmables from them and they work great.

Carole Borges's picture

Gads Bill that's a ton of lights!

It reminds me of the day my daughter called me after an electrical storm to say she had lost five TVs. Whoever designed your house must not have factored in the cost of electricity. It sounds like you've really been helped by the CFLs. Good for you!

BTW old refridgerators are the worst! I also have saved a lot by purchasing a new energy efficient one.

Most of the year, I can turn off my A/C between 11 and 4. This also helps.

Justin's picture

I'm a stickler for turning

I'm a zealot when it comes to turning off the "power vampires" that are plugged in my home...paper shredder, phone chargers, power strips for my pc and tv, coffee maker, microwave oven, toaster (I leave the cable box plugged in so it stays updated). They dont use a lot of electricity when in stand by mode (feel the end of the adapter/plug thing...most of them will be warm to the touch) but every little bit counts when you start adding up days/months/years. You would be surprised at how many things you leave plugged in when not in use. I need to trade in my cable box (Comcast/motorola DVR) for one of the newer versions. Motorola updated them so that the drives are not constantly spinning/wasting electricity/excess heat.

WhitesCreek's picture

I ate a can of tuna last

I ate a can of tuna last week. How much mercury sequestration does that count toward?


I'm jealous of your electrical reduction, actually. Keep it up.

ATSF616's picture

New refrigerator saves even more

We've had CFLs in just about every fixture in the house where they'll fit (about 23 at last count) for at least five years, so I can't easily come up with our savings on that score.

However, we did replace a 21-year-old refrigerator about four months ago. After four billing cycles, it looks like our total household consumption has dropped about 25 percent.

June 2006-Feb 2007: Avg 459 kwhr/mo
Mar-June 2007: Avg 341 kwhr/mo

The new one has an ice-maker, which we've never had before, and I've only recently discovered that feature does use about 10 percent more power than a comparable model without an ice-maker.

Factchecker's picture

Might have you beat on raw

Might have you beat on raw number of bulbs, but probably shouldn't be bragging. I count over 35 CFLs inside and out, including deck, garage, and bath lights (where there's a row of four). But it's hard to know what we're saving. They were replaced gradually and many aren't used much or at least more than a few minutes here and there. Our most used lighting is fluorescent tubes. The standard 48" bulbs are 34-40W ea, but what extra wattage is used by the ballasts? I don't know. I oughta figure that out sometime.

Refrigerators are a bit of a puzzle too. Ours is 16 years old and it was rated to use 888kWh/year per EPA. So using $0.10/kWh as a cost basis, we're now paying about $7.40/mo. to cool our food (888x0.1/12). (Though KUB's published rate is only $0.07125/kWh. I thought it was $0.0925/kWh. Hmmmm.)

Anyway the newest refrigerators of comparable size are rated to use about 450kWh/yr per Let's just round that to 444 to assume a new unit would use half the power of our present one. That would only save less than $50/yr, less for KUB's lower rate than I used. So the payback on a new fridge would be >20 years if a new one costs $1000. And monthly electrical usage drops only 37kWh. Not ready to do that yet, especially considering lifecycle environmental costs.

June 2006-Feb 2007: Avg 459 kwhr/mo
Mar-June 2007: Avg 341 kwhr/mo

You're a saint if your usage is that low! I'm jealous.

ATSF616's picture

June 2006-Feb 2007: Avg

June 2006-Feb 2007: Avg 459 kwhr/mo
Mar-June 2007: Avg 341 kwhr/mo

You're a saint if your usage is that low! I'm jealous.

Some disclaimers:

We are in north-central Indiana, meaning maybe slightly cooler summers, though certainly not by much.

House is about 12 years old, and seems fairly well-insulated. Doesn't get unbearably hot inside unless outside temps/humidity are hellish.

Don't like to sleep with AC on unless there is just no alternative -- prefer open windows and ceiling fans, which we have in every major room except the kitchen (five total).

Natural gas furnace/water heater/kitchen stove.

Not big TV-watchers.

Computer is only on while being used.

I'm a real stickler for turning off lights not in use, plus we have the 23 or so CFLs.

No magic involved....just common-sense stuff, and we're not Luddites.

smalc's picture

I switched most of our

I switched most of our standard bulbs to cfl a while back, but just recently started switching the globes above the bathroom sinks (G25 bulbs?). I bought some GE bulbs from Target for about $6 each. To my disappointment, they both lag a second or two coming on and take about 20-30 seconds to get to full brightness. Neither are too bad, just annoying.

Unfortunately, the two fixtures we use most need those tiny globes (G16) with the small base. No cfls will fit in them (the torpedos are too long), plus incandescents are expensive and don't last long. I've wondered how long it would take to break even on new fixtures.

R. Neal's picture

I count over 35 CFLs inside

I count over 35 CFLs inside and out

At first I thought, wow, there's no way we have that many light bulbs.

But I went around and counted them up, there are about 52 inside and in the garage (counting fixtures with multiple bulbs, so there would actuallly be more bulbs than that but we don't fill up all the sockets in some of them), and about 12 more outside.

Sheesh! I had no idea.

But what's weird is that the 6 CFLs we installed account for about 90% of our usage, and they're on most of the time.

We have lots of windows that let in lots of light (even when we close the shades to keep out direct sunlight in the summer) and we hardly every use all these other accent lights and hanging chandoliers and overhead ceiling fixtures and fan lights and hall lights, etc. etc. etc.

Sibyl's picture

I have a small house and not

I have a small house and not many lights. Only eight light bulbs. I have switched out six of the light bulbs for compact fluorescent. I also raised the typical daytime indoor air temperature to about 84 degrees (from 78) and night time temperature to 78 (from 74). I also am now turning off my computer and its power strips and peripherals when not in use. Doing all of these things has cut my KUB bills by about 40%. One of my major power-suckers is my very old and inefficient fridge. I am a renter, and have asked my landlord if he would split the cost of a new fridge with me, but he won't. Also, my house is very poorly insulated and my heat and a/c have to work very hard to keep the place comfortable. I'm planning on buying a house next year and hope that once I'm a homeowner I can do more to stop wasting energy.

R. Neal's picture

Doing all of these things

Doing all of these things has cut my KUB bills by about 40%.


Carole Borges's picture

Electric lawnmowers.. A little off-topic but...

Last year I bought an electic battery-operated lawn mower and weed wacker. I have a large yard, but they've been just great, and I didn't notice much difference in my electric bill from the charging. They are very quiet, so noise pollution is down, and I like the idea of not having to mix or store any gasoline. They're both lightweight with no cords. The mower can only last about an hour, which is about all I can last in the heat, so I do my 225ft deep yard in sections. They did cost a bit more upfront, but I'm really happy with these tools.

R. Neal's picture

battery-operated lawn

battery-operated lawn mower

You have grass to mow? Consider yourself lucky with this drought and all.

Mello's picture

outside CFLs?

When we replaced nearly every one of our bulbs we ended up having to put the old ones back in areas that were unheated-barn, garage and decks.

Have I missed a special CFL for cold areas?

Factchecker's picture

Have I missed a special CFL

Have I missed a special CFL for cold areas?

Did they die early? We've had regular off-brand (HD/Lowe's*) spirals outside for years and I think only one has died. They don't get used much, but I turn them on when it gets very cold just to see how they do. They just take longer to brighten up. The fixtures are just covered from the weather by plastic globes.

I bought some GE bulbs from Target for about $6 each. To my disappointment, they both lag a second or two coming on and take about 20-30 seconds to get to full brightness.

The very first CFLs we bought were those. I'm surprised GE hasn't fixed that delay. Most are still OK bulbs, but at least 2 or 3 of that first bunch didn't last too long.

*Our latest ones carry the Commercial Electric brand. They work great everywhere I've installed 'em. electic battery-operated lawn mower and weed wacker.

We've had a B&D cordless whacker for years. I love how well it works, but it's been in the shop several times and it needs its third lead acid battery. Had to break down and buy the wife a 2-stroke, which I despise. But it gets major weeds and brush she insists we cut.

Bought a corded electric mower this year just because. I love it except fighting that damn cord hardly makes it worth it. The battery version was much more expensive, heavier, and made me worry about the same type of battery problems I've had with the whacker. (I too haven't mowed in months, though.)

I think there are a lot of improvements that could be made with cordless mowers. If anyone has a million to invest, we could make the Segway of mowers. Only half-kidding.

Mello's picture

outside bulbs

Yep, we got ours at Lo-Depot but after the major hassle of putting them in the barn they just would not light up correctly. The one on the back porch seems to work fine now that it is very warm outside but in the winter it was just about useless.

For the front of the house I finally found solar lights that work very, very well. These are on a line and instead of the solar collector being on each single light it is a larger collector positioned away from where I need the lights.

R. Neal's picture

I read somewhere that site

I read somewhere that site wiring problems can cause issues with CFLs. Don't recall the specifics, but that might be your problem in the barn.

As for temperature range, newer CFLs are designed with wider operating temp ranges, and some are specially designed for extreme temperatures and outdoor use.

Go to one of the websites that has lots of different brands with specs and look for some designed for that purpose. It seems like there are new ones coming out about every week or two for this application or that.

This site has a handy selector to find bulbs by type of application (they just identify the brand/type, they don't sell them):


Here's another one (they sell them):


This company has a good selection with some detailed application notes:


Factchecker's picture

I read somewhere that site

I read somewhere that site wiring problems can cause issues with CFLs. Don't recall the specifics, but that might be your problem in the barn.

Here's something weird. We have a few (indoor) switches that are lighted when off, to see in the dark. There are a few circuits in the house where these are incompatible with some CFLs. There's some sneak current, or something like that, that causes the CFL to flash intermittently when it should be off. So there's one place where there's still an incandescent. I somehow got around it for all our other sockets.

I don't think all CFLs do it, but just serves as a reminder that a CFL is an electronic device instead of just a wire filament.

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