Re: Anyone moved to LED Lighting?

[nobody@xxxxxxxxxxxx (Dave Houston)]

don@xxxxxxxxxxxxxx (Don Klipstein) wrote:

>In article <4b3bf8e7.53435281@xxxxxxxxxxxxx>, Dave Houston wrote:
>>
>>Rod Elliot has a section on Power Factor and CFLs which appears to indicate
>>it's a much bigger problem in terms of generator fuel consumption.
>>
>>     http://sound.westhost.com/articles/incandescent.htm#pf
>
>  Since most grid electricity has generator winding, transmission and
>distribution losses totalling much less than power delivered, reducing
>watts reduces generator load and fuel consumption even if the amps stays
>the same.
>
>  Meanwhile, the article did say that a 15W CFL (which typically replaces
>a 60 watt incandescent) typically takes 29 VA (volt-amps) - total VA,
>not just VA other than watts.

I have never argued that CFLs do not save energy, merely that they do not
save as much energy as proponents usually claim. Lumens per watt does not
account for PF issues (nor THD if its not included in PF calculation). What
I said was that some (not all) of the savings attributed to CFL are
imaginary. Congress should have mandated minimum standards for PF and THD.

Wikipedia has a good explanation of PF.

http://en.wikipedia.org/wiki/Power_factor#Importance_of_power_factor_in_distribution_systems
<quote>
The significance of power factor lies in the fact that utility companies
supply customers with volt-amperes, but bill them for watts. Power factors
below 1.0 require a utility to generate more than the minimum volt-amperes
necessary to supply the real power (watts). This increases generation and
transmission costs. For example, if the load power factor were as low as
0.7, the apparent power would be 1.4 times the real power used by the load.
Line current in the circuit would also be 1.4 times the current required at
1.0 power factor, so the losses in the circuit would be doubled (since they
are proportional to the square of the current). Alternatively all components
of the system such as generators, conductors, transformers, and switchgear
would be increased in size (and cost) to carry the extra current.

Utilities typically charge additional costs to customers who have a power
factor below some limit, which is typically 0.9 to 0.95. Engineers are often
interested in the power factor of a load as one of the factors that affect
the efficiency of power transmission."
</quote>

Often, the claims made by CFL/LED proponents are preposterous. I've seen
numerous articles in main stream media (e.g. NYT) and elsewhere claim that
switching to CFLs will reduce total energy requirements by 20-25%. We
couldn't achieve half of that even if we turned off all lights in every
sector. Since nearly all of the savings have to come in the residential
sector we'll be doing quite well if we get a 1% reduction in total energy.
Disparities greater than an order of magnitude cannot be attributed to
errors in calculation but can only be due to deliberate distortion and
propagana.

This was posted to this thread earlier...

http://en.wikipedia.org/wiki/File:Sources_of_electricity_in_the_USA_2006.png

This has a table showing worldwide energy reserves...

http://tonto.eia.doe.gov/energyexplained/index.cfm?page=coal_reserves

If the projections for shale gas prove accurate, the picture will change
significantly but, at present, the USA has large reserves of coal and small
reserves of oil and natural gas. That almost guarantees that our use of coal
will increase.  (Montana is about to open a huge coal reserve to mining.)
Given that reality, it makes more sense to work toward ways we can use the
coal without increasing our carbon footprint (which may or may not be
possible/practical), If we were to take all the money we now spend on energy
driven wars in the mid-east and spend it on clean coal research, we might
even have a slim chance at long term survival.