>> >While this may be a penny-wise solution in terms of bulb cost,
>> >it could very well be pound-foolish in terms of electricity cost.

>> Only if you add more lamps to compensate for the decreased
>> brightness,
>> which wasn't the idea of the scheme.  As Joes web page shows,
>> dropping
>> the voltage by ~5% significantly increases lamp life whilst still
>> giving
>> acceptable light output.

> If you need less light, it then becomes more cost effective to
> simply
> purchase a lower-wattage bulb.  Sure, you'll need to replace the
> bulb
> more frequently, buy you will save money in the long run.

Bulb costs, especially of fancy ones, are liable to be an average of
$NZ2. (Std bulb $0.50 - $1. Fancy bulbs $2 - $5).  Bulb lifetimes in
some applications can occur within months and are liable to normally
be 1 to 2 years. Adding a series resistor can, according to Joe's
experience, extend lifetime indefinitely - say 4 years. Savings for a
6 months to 4 year life extension are $2 x (2 - 0.25) = $3.50 per
year. I can imagine that a suitably constructed resistor base or
inline add in (terminal block and resistor mounted in junction box)
would meet that cost. Labour cost of installation is very well offset
by bulb changing labour. In fact, based on labour costs alone, the
resistor solution wins hands down.



        RM

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