Greetings from open4energy A most informative discussion and excellent points being made by all. I live in a small two bedroom apartment and recently replaced all the old incandescent bulbs with latest version Energy Star approved CFL bulbs. I have my opinions on what is best to do, but rather than express them I decided to monitor the energy profiles, before and after, using a Watt-up Smart Circuit 20. Here is the graph, it compares the two sets of light bulbs, each set being turned on in the same sequence, with 15 seconds between them. http://open4energy.com/forum/home/lig/energy_saving_light_bulbs_0912102218 The theoretical saving from the bulbs is a little under 75% if I adjust for the bathroom fan which remained unchanged. For those needing exact numbers, the peak load for the incandescent bulbs was 819.7 Watts with Power factor of 99% - while the load for the new CFL's was 230.6 Watts with Power factor of 79% I then wondered how this played out in real life. I did a second test, monitoring the actual living energy use on our bedroom/office/bathroom circuit for two days, once with the original bulbs and then again with the new CFL bulbs. Here is the graph of the four days of data, again monitored using the Wattsup Smart Circuit 20 http://open4energy.com/forum/home/lig/energy_saving_light_bulbs_incandescent_cfl_0912142219 Do note that this includes the energy used by my computer in the home office. Energy use in the first two days was 4657.6 Watt Hours, and in the second two days was 2400.3 Watt Hours, a reduction of 48.46% And much to my surprise, the Power Factor for the CFL two days was above 80% - I believe that the laptop computer with its mechanical reactive power was creating some compensation on the circuit? And if the energy data is "boring" the graphs provide way too accurate a record of when I worked on the computer, and when someone needed the bathroom in the night ......

Hi again there Chris, To summarize a bit and focus more on the cost related issues, like you said No doubt CFLs can save energy, but not as much as supposed. To begin with the simple usage factors: Lost, broken or malfunctioning expensive bulbs cost more to replace than cheap ones. Meanwhile, the "expensive to buy but cheap to use" concept tends to lose out, -- in rarely used lamps around the house -- in short stay situations, vacations, second homes etc Brightness problem of CFLs: Supposed equivalents are not actually equivalent in brightness, so higher energy using CFLs needed for adequate brightness. See recent testing of CFL brightness versus ordinary bulbs: telegraph.co.uk/news/worldnews/europe/eu/6110547/Energy-saving-light-bulbs-offer-dim-future.html More, with other links: http://www.ceolas.net/#li15rbx CFL Lifespan is lab tested in 3 hour cycles. That does not correspond to real life usage and numerous tests have shown real life type on-off switching reducing lifespan. Leaving lights on of course also uses up energy, as does the switch-on power surge with CFLs Also, CFLs get dimmer with age, effectively reducing lifespan Ceolas.net/#li15sox Power factor: Few people know that CFLs typically have a power factor of 0.5 - that means that power stations use up twice as much power than what the CFL rating shows. This has to do with current and voltage phase differences set up when CFLs are used. Although consumers do not see this on their meters, they will of course have to pay for it on their bills. This is explained with official links including to US Dept of Energy here: Ceolas.net/#li15eux Heat benefit from using ordinary incandescent light bulbs ceolas.net/#li6x A little bulb near the ceiling may not seem like much, but room heat substantially rises to the ceiling (convection) and spreads downwards from there. As shown via the above link with American and Canadian research references, half of more of the supposed switch savings are negated in temperate climates. <b>Effect on Electricity Bills</b> Inasmuch that energy use <b>does fall</b> with light bulb and other proposed product efficiency bans, electricity companies make less money, and they’ll simply raise the electricity bills to compensate (not least in USA, power companies often have their own grids with little supply competition) Energy regulators can hardly deny any such cost covering exercise… One might add that as Scottish and Cambridge university research shows (as referenced on the website) energy efficient products effectively mean cheaper energy so people just use the appliances more, leave them on etc. With CFL lighting that is actually advised anyway (due tom on-off switching reducing lifespan, but of course leaving them on as said in turn uses up energy... OK thanks again for a nicely put together site. Learning something every time I use it.

Thanks for the great comment!

Peter, thanks for the comment, but I was merely doing the cost analysis from a consumer standpoint, not a life-cycle analysis from an environmental standpoint. It all depends on what the consumer cares most about. If it is just saving money then the CFL is the hands down winner. If it just saving the environment, then more analysis needs to be done to look at shipping costs, how the product is manufactured, how it is disposed of, packaging, etc...