Dim bulb?

How much power do Americans guzzle for lighting? 18

light bulb 125wCan anyone out there help me out?

Doing some fact-checking for a book, I ran across a question I didn't know the answer to: How much power is consumed by lighting in the U.S.? I spent a bit of time Googling for an answer, but at risk of looking like a dim bulb, I have to confess -- I just couldn't figure it out!

The Green Home Guide says that lighting uses 5 to 10 percent of household electricity. That lines up pretty closely with figures from the U.S. Energy Information Administration (part of the U.S. Department of Energy), which reports that, as of 2001, electric lighting represented almost 9 percent of total household power consumption.

But another branch of the Department of Energy says that lighting accounted for over 16 percent of electricity use in households (PDF), and 24 percent in offices and stores (PDF). Based on these figures, and after I add in industrial electricity consumption, it looks to me as if lighting represents about 17 percent of total electricity consumption in the country.

So that's getting pretty close to the figure of 20 percent, which appeared in our 1999 book, Seven Wonders. But the text of that book also notes that electricity consumption from lighting would be even higher, if you include the extra air conditioning that's required by all those hot bulbs in your house in summertime. And, in fact, this New York Times story from earlier in the year cites figures claiming that lighting consumes close to 22 percent of the nation's electricity.

But that's not the end of it: the Worldwatch Institute report says that lighting consumes 15 percent of household electricity, but up to 34 percent of the nation's electricity overall!

Hmm. So light bulbs represent somewhere between 5 percent of home electricity consumption, and 34 percent of total, economy-wide consumption. That last figure is a real outlier, so I'm inclined to discount it. Still, it's quite a spread, and all from reputable sources.

Which leaves me baffled and, er, in the dark. So if anyone else can shed some light on the subject, feel free to illuminate me.

Clark Williams-Derry is research director for the Seattle-based Sightline Institute, a nonprofit sustainability think tank working to promote smart solutions for the Pacific Northwest. He was formerly the webmaster for Grist.

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  1. Tasermons Partner Posted 1:28 am
    09 Dec 2007

    Goin' down...As americans switch over from incandescents to CFLs and LED lights, the amount of power consumption devoted to lighting is expected to go down.  Likewise, since CFLs don't emit near the amount of heat that traditional incandescents do, it should also help cut down on cooling costs associated with air-conditioning in the summer (though there might be slight increase in heating costs durin' the winter).
  2. sunflower's avatar

    sunflower Posted 2:00 am
    09 Dec 2007

    If nobody sees the light then does it exist?I once calculated illegal grow lights exceed one gigawatt.  And what about all those street lights?
    Our solar home is so efficient that when the Winter sun does not shine we just turn on a few lights.  Most of our waste heat comes from the refrigerator.
  3. Kelpie's avatar

    Kelpie Posted 6:25 am
    09 Dec 2007

    light bulbsClark,

    I found some good figures at the Rocky Mountain Institute website. There are a couple of pdf files you can download there that detail an analysis of lighting power consumption looking at home, industrial, municipal and commercial lighting. The data is probably a few years old but will at least give you a snapshot of the status quo prior to the current CFL push.

    Check out my ecothriller novel Primal Tears at amazon.com and other booksellers.
  4. Jon Rynn's avatar

    Jon Rynn Posted 7:37 am
    09 Dec 2007

    Clark, my research on this subject......came up with residential lighting accounting for 3.1% of all electrical use in the country, or less than 10% of residential electrical use.  Commercial lighting accounted for 7% of all electrical use, or more than double residential.  You can look at the bottom of my article here on the subject (the rest of the article is rather snarky, you may like it even so).
    The figures from the EIA for electrical use are presented for industry, residential, and commercial, and they do the surveys in different years, so I tried to combine the various years with a certain amount of weighting (see footnote six for more of an explanation).  
    I don't know where the NY Times gets the higher figures; it seems to me that the EIA figures should be the "rawest".
  5. Jon Rynn's avatar

    Jon Rynn Posted 7:53 am
    09 Dec 2007

    And looking at the sources in your post......the N.Y. Times just quotes the industry group, so we don't know where those sources came from...Worldwatch has no sources...the EIA study you quote seems to be the same that I used, however you state that they are talking about total power, but they are talking about total electricity (don't mean to nitpick)...which leaves the Energy Department BTU studies.  
    Frankly, I'm not sure how to read those, they mention "on-site" and then "total primary", and a footnote refers to "generation and transmission losses", so maybe they are referring to the btu's lost at the coal plant?  In which case, if you look at "on-site", it's 6.5% of all power for lighting, which probaly is in the ballpark of the 8.8% of residential electrical use cited by the EIA for lighting.
  6. caniscandida Posted 8:46 am
    09 Dec 2007

    dim memory too ...Back in December, 1973, as part of a coordinated national energy-conservationist response to OPEC's oil embargo, didn't Richard Nixon cancel the national Christmas tree?  Or at least the lights on it?  And didn't he make a point of not lighting up the White House for Christmas?  And didn't he urge all Americans to go easy on Christmas lighting?
    http://en.wikipedia.org/wiki/1973_oil_crisis
    But then, was it not pointed out that in fact, illumination accounts for relatively little of our energy use?

    Chickens are our cousins! So are fish! So are other sentient animals! Let us learn to be kind.
  7. spaceshaper's avatar

    spaceshaper Posted 8:48 am
    09 Dec 2007

    Whichever..it's a lot more than it need be. It's common now for new homes to have close to a kW of lighting just in the kitchen - and not just used at night.... Clearly neither necessary or sustainable.



    The true meaning of life is to plant trees, under whose shade you do not expect to sit.
  8. lmoore Posted 2:04 am
    10 Dec 2007

    not dimYou're not alone in your confusion!
    An analysis by Lawrence Berkeley National Lab (pdf) estimated that the USA uses about 13 percent of total electricity for lighting. The service sector used 3-4 times more electricity than either residential or industrial sectors. (Why so high? Think of retail stores, parking lots, warehouses, etc.)
    However, the author (who published a short version of his paper here) pointed out that data and methods are frustratingly spotty and incomplete.  
    The United Nations also describes these estimates as "difficult".
    Even if we're not certain of the exact numbers, it's obvious that energy efficiency has a huge role to play in any effort to decrease energy use, fight pollution and slow down global warming.
    If you want to learn more about CFLs, my colleagues have assembled a fantastic guide to CFLs, including reviews, FAQs, and a savings calculator.
    Lisa Moore

    Environmental Defense

    Climate411.org
  9. Sam Wells Posted 2:06 am
    10 Dec 2007

    CFL, LED, and ChristmasGood posting - I'm against light pollution at night and wondered if more could be done about it - wouldn't it save a ton of money?
    CFL - anybody else having problem with them spirochete bulbs?  They're supposed to last years and I get maybe 2-3 times as long as a regular light bulb.  The ones made in China were especially disappointing, and the ones from GE more expensive and tend to "brown out" and flicker just as well.  Longevity is not as advertised.
    LED - might take a few years but for Christmas lights, I am totally down with them.  Only 10-20% of the juice required!  The colors never dim, wash, or fall off.  During this Holiday season, I'm especially impressed by them.  

    Onward through the fog
  10. Jon Rynn's avatar

    Jon Rynn Posted 2:34 am
    10 Dec 2007

    Lisa Moore --If you look at the paper on which the one you referenced was based, Lighting Market Sourcebook for the U.S., on page 5, they show EIA's more conservative number (for 1995, an old statistic, but close enough to 10 years later to not make much of a difference).  They also show various other estimates, all of which are higher, althought the EIA surveyed the most households.  It might be useful, considering the differences, to look at use by state or area.  
    In any case, if lighting uses more electricity than EIA reports, and assuming EIA accurately reports total national electrical use, then the numbers for some other uses -- appliances, cooling -- would have to come down to compensate for more electricity for lighting.  That's not to say that lighting should not be made more efficient, I'm just arguing for being more conservative with the numbers, and to stress that heating and cooling are the biggest problems, as far as electricity use goes (and they could be addressed by using geothermal exchange systems).
  11. lmoore Posted 2:58 am
    10 Dec 2007

    AbsolutelyI agree, we have to increase energy efficiency for as many end uses as possible. Fortunately there are a lot of ways to do it quickly and cheaply.
    Yahoo! has a 'carbon calculator' that shows the emissions savings you can get with various changes around the house. Heating, cooling, and appliances are really important. (Full disclosure: Environmental Defense helped with some of the numbers behind the calculator.)
    The references I gave in my earlier comment simply make it clear how difficult it can be to nail down the exact numbers - which isn't an argument to ignore any energy use.
    cheers,

    Lisa
    Lisa Moore

    Environmental Defense

    Climate411.org
  12. amazingdrx Posted 3:39 am
    10 Dec 2007

    36% of GHGIs assigned to heating/cooling costs.  That's a huge load of conservation that could be acomplished with geo heat exchange. Like Jon said.
    LED lights everywhere, especially in those retail stores would help on the lighting conservation.  Solar skylights that bring light all the way down into buildings through conduits are good too.
    If Walmart had them mass produced, like they did CFLs, then used them in their stores, it should bring the cost way down.
    Generating green kwh gets a subsidy, conservation gets a subsidy of sorts, the money saved on kwh not used.
    Are further subsidies needed for conservation?  Probably not, just use the money to convert government buildings to LEDs and geo heat exchange.  That impells large orders and mass production too.

    http://amazngdrx.blogharbor.com/blog
  13. Nucbuddy Posted 4:00 am
    10 Dec 2007

    LED's are half as efficient as linear fluorescentsAmazingdrx wrote: LED lights everywhere, especially in those retail stores would help on the lighting conservation.
    LED lights draw twice the power of linear fluorescents. (50 lumens/watt vs. 100 lumens/watt, for the former vs. the latter, respectively.)
  14. Laurence Aurbach Posted 5:44 am
    10 Dec 2007

    And another oneHere's another study to add to your bibliography. It was performed for the DOE by a consulting firm.
    Navigant Consulting, U.S. Lighting Market Characterization Volume I: National Lighting Inventory and Energy Consumption Estimate. Washington DC: Building Technologies Program, Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy, September 2002. http://www.eere.energy.gov/buildings/info/documents/pdfs/ ...
    Navigant Consulting, U.S. Lighting Market Characterization Volume II: Energy Efficient Lighting Technology Options. Washington DC: Building Technologies Program, Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy, September 2005. http://www.eere.energy.gov/buildings/info/documents/pdfs/ ...
    The study found that light bulbs use approximately 22% of US electricity. Incandescent bulbs account for 42% of this amount, or 9% of all U.S. electricity consumption. Furthermore, the consultants identified 52 innovative lighting technologies; on average, each technology could save 0.7 quads of consumed electricity annually.

    Ped Shed Blog
  15. amazingdrx Posted 8:25 am
    10 Dec 2007

    Yeah butLEDs can be lower power targeted to just where the light is needed, then switched automatically to go on/off depending on human need to see.
    That way the actual end use efficiency would far surpass flourescents running 24/7 at a convenience store for instance.  Shelf directed lighting would go on/off as you walked down the aisle.

    http://amazngdrx.blogharbor.com/blog
  16. Clark Williams-Derry's avatar

    Clark Williams-Derry Posted 9:09 am
    14 Dec 2007

    Thanks!Thanks for all the super-helpful comments, everyone!!
  17. jlhagstrom Posted 7:48 am
    23 Dec 2007

    parsing the figures"But that's not the end of it: the Worldwatch Institute report says that lighting consumes 15 percent of household electricity, but up to 34 percent of the nation's electricity overall!"
    Sorry to be commenting on this so late but I just read it.
    A point:  note that the above quote would seem to indicate that non-household lighting uses 19 percent of the nation's electricity -- we need a serious movement to encourage businesses that cannot seem to turn off lights in offices after hours etc., to change their habits! Surely some people from the grist community work for some of these businesses and corporations -- how about it, guys?
  18. spaceshaper's avatar

    spaceshaper Posted 9:01 am
    23 Dec 2007

    LED nightlightsare pretty cool too - and at 1/4w rating or less they are said to use less energy running continuously than with a sensor to turn them off in the daytime. The sensor apparently uses more juice than the light. I have one which casts a quite beautiful blue glow over our entire central hallway. For comparison, standard plugin incandescent nightlights are rated about 4W.

    The true meaning of life is to plant trees, under whose shade you do not expect to sit.

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