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Lighting the Way to Lower Electric Bills

Posted by Glenn on October 18, 2005 - 10:33pm in The Oil Drum: Local

I recently discussed how I lowered my electric bill from 8KWh/day to just 4.7KWh/day using simple easy to implement techniques, such as using Compact Fluorescent Light (CFL) bulbs for versus Incandescent bulbs for lighting. Here's why CFL lighting makes so much common sense for your wallet and sustainable living.

Overall Importance of Lighting and CFL
According to the US Department of Energy (DOE), lighting accounts for one quarter of electrical demand in the US at a cost of $37 Billion a year. DOE says CFLs "are the most significant lighting advance developed for homes in recent years," and that their "energy savings and superior longevity make CFLs one of the best energy efficient investments available."

Energy Use
CFL bulbs use 70-75% less electricity than traditional incandescent bulbs. That means that light from an 11w fluorescent bulb compares to a 40w incandescent bulb, but uses 72% less energy. (14w compares to a 60w incandescent, 20w to a 75w, and 25w to 100w). The main problem with Incandescent bulbs is that 80-90% of the electrical energy gets lost as heat.

Longevity and Cost
They last about 10 times longer than incandescents too. This means that for a slightly higher up front cost for the CFL, you will save on running costs in lower electricity bills and you will save on replacement bulbs. CFLs cost less than $10 and will net the buyer between $30 and $70 in savings over its lifetime on electricity bills and replacement bulbs

Reduction of Greenhouse Gases
The lower electrical demands reduce the amount of carbon emission depending on the source of that electricity. Each CFL replacing a regular bulb prevents emissions of 1,000 to 2,000 pounds of greenhouse gases (CO2) and 8 to 16 pounds of polluting sulfur dioxide from power plants, as well as eliminating the need to produce, and ultimately discard, up to a dozen incandescent bulbs.

Opportunity
There are nearly 3 billion light sockets in the U.S., most of which are candidates for CFL replacement, but very few residential sockets use CFLs. CFLs are available from local hardware and home-improvement stores.

Sources: Safe Climate
Improvements Catalogue]
Energy Star

Lighting the Way to Lower Electric Bills

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6 comments

The Interloafer on October 19, 2005 - 1:15am Permalink | Comments top
We switched to all-CFL lighting back in January. I don't go to big box stores much, but this was the perfect opportunity to go to Home Depot on 23rd Street. So I'm glad we did that, but here's the question: They save energy, but do they save you money? Incandescent bulbs were like, what, 75 cents and last for two years? An equivalent CFL was $8 and lasts for nine years. It will take a whole lot of energy savings to earn back that $7.25.
michaelrecycle on October 19, 2005 - 10:11am Permalink | Parent | Comments top
If your numbers are correct, the cost difference between incandescents and CFLs is actually only approximately $4.65, not $7.25.  The reason is that at 75 cents per bulb that only lasts 2 years, if you want to compare that to an $8 CFL that lasts for 9 years you need to consider the cost of replacing the incandescent every 2 years for 9 years.  That'll cost you about $3.35.

But these numbers are all wrong anyway...incandescents usually last for less than a year, and you can get CFLs for $4 or $5 at bulbs.com, so you definitely save money and energy by switching to CFLs.

Glenn on October 19, 2005 - 12:44pm Permalink | Parent | Comments top
The best stuff I found online was the cost comparisons were that CFLs cost $10 for the bulb plus running costs while incandescents cost $30 for the bulbs and running costs. I'm not sure what the assumptions were for the cost of the bulbs or the electricity. They seem to more than make their money back based on the calculations I've seen. In practical life though I agree it isn't that easy to measure.

This is all assuming that electricity rates remain as low as they have been for the last 20 years. Looking out the lifetime of a new bulb installed now that lasts for 8-12 years, you could be looking at more substantial savings.

What is definitely true is that these reduce emissions (70-75% by most estimates) for each hour they are on.

A combined program of using CFLs as much as possible along with simply reducing your overall usage of lighting should result in lower electrical bills, lower emissions, and less hassle of dealing with replacing bulbs.

The Interloafer on October 20, 2005 - 1:11am Permalink | Parent | Comments top
O.K., thanks guys.  That's interesting.  I'm happy just to be reducing emmissions, even if it means paying a bit more - but from what you guys are saying CFL's are probably a money-saver or at least a wash.
Glenn on October 20, 2005 - 8:41am Permalink | Parent | Comments top
I think come the holiday season, these are going to be great stocking stuffers!
The Interloafer on October 21, 2005 - 9:19pm Permalink | Parent | Comments top
You're absolutely right. Last Christmas, my stocking was stuffed. That's how I found out about these.

Lighting the Way to Lower Electric Bills

PDF version

6 comments