It's very difficult to make hard and fast statements about the efficacy of LEDs
at this time. Standardized measurements have only recently been developed and
published and the early round robin tests sponsored by DOE have shown that few
meet the claims made by the manufacturers and distributors. Testing and
comparisons are on-going. Although there are exceptions, most white light LED
packages still trail the better CFLs in actual lumens/watt delivered under
standardized testing conditions (monochromatic LED's can be very efficient at
some wavelengths, but lose efficacy when packaged to produce "white" light).
LED technology is evolving rapidly and the holy grail of 100 lumens/watt is
still the goal and is considered possible in production numbers in the
not-too-distant future. Problems of lower light output due to heat remains a
real issue. But it's all getting better.
Alan Lewis
"Victoria"
Gulfstar 41 #160
Lying Kittery, ME
K1ALL
> From: [email protected]
> To: [email protected]
> Date: Thu, 2 Jul 2009 10:20:07 -0400
> Subject: [Liveaboard] Lumens per Watt
>
>
> In the same Home Power magazine (Feb/Mar 09) I copied the Battery
> Equalizing essay from, there was another article about installing a PV
> system in a jungle village that stated in the text:
>
> "Key to the plan was LED bulbs, which use less than a third of the energy
> of compact fluorescent bulbs..."
>
> While in a sidebar it was stated:
>
> "Compact fluorescent lamps produce at least 50 lumens per watt, while
> current available high-brightness LEDs can produce about 30 to 35 lumens
> per watt.
>
> These contradictory statements are confusing. Can anyone out there give us
> the true facts?
>
> Norm
> S/V Bandersnatch
> Lying NYC
>
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