> And an opinion piece by the editor of Silicon Chip
> "Compact fluorescent lights are not economic"
>
> http://www.siliconchip.com.au/cms/A_102164/article.html

That was written in 2004. I'm surprised. He's wrong.
Or, at least, my overwhelming experience of CFLs is quite different 
from his. I can categorically state that I have had some versions last 
well over the rated 8000 hours as I have a lamp my electrical workshop 
and another in my front path light that are always on, and the bulbs 
last typically well over a year. I write the date that I put CFL bulbs 
into service on their base. I have had some fail long before expected, 
but overall the results are acceptable, if not as good as some claim. 
Given the current low cost of CFLs and the substantial savings in 
energy use, it doesn't take long to justify their cost on energy 
savings alone. Note that CFLs save money on energy ONLY if you do not 
have thermostat controlled heating. Any time you use a 
thermostatically controlled heater energy sources such as light bulbs 
contribute to the heating and reduce heating power costs 
proportionately.

Simple example of savings. Compare an incandescent 100W bulb and a 25W 
CFL. (usually 20W are sold as 100w replacements but they don't quite 
meet 100W equivalent light output so lets be fair). Electricity costs 
about $NZ1 per watt per years continuous operation. That varies with 
area, and the price is rising, but it's an OK approximation. If an IB 
(incandescent bulb) and CFL are assumed to cost equal amounts of 
capital per hour run then power savings are all that needs to be 
compared. Even factoring in bulb costs does not make much difference. 
Energy savings per year run 24/7 are 100-25 = $75 per year. Run a bulb 
10% of the time = 2.4 hours per day and the saving is $7.50. As CFL 
bulbs now often cost under $3 and IBs are down to say $0.50 there MAY 
be a slight extra bulb cost for the CFLs. But its far less than 
$7.50/year.

I run an often or always on CFL in several locations. Front porch, 
path light, workshop. There are a few other areas where they are often 
on. At $1/year/watt and with a small wattage CFL the costs are 
acceptable. I would not consider doing this with IBs.

I just went and checked the ALWAYS on front path light. It was 
installed on 22 September 2003. That's about 11.700 continuous running 
hours so far. It's an 8 watt bulb so running costs so far are about 
$11. ($11.22 at 12 cents per unit.)

My workshop bulb was installed in 15 October 2003 after having been 
moved there from some other (unspecified) location so total hours are 
unknown but at least as long as the path light. .

A significant failure mode is mechanical damage due to careless 
handling. It's far easier to crack the bulb seal on a CFL than on an 
IB. Due care is required,


There are few places where I would recommend an IB these days.




        RM 

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