| Re: Do not feed the Dinosaur!
Eeyore wrote:
>
> Bill Baka wrote:
>
>> Eeyore wrote:
>>> donquijote1954 wrote:
>>>
>>>> A typical 25 watt fluorescent light
>>>> bulb, which replaces a 100 watt incandescent bulb, will last 8 hours
>>>> on 200 watts worth of power. LEDs (light emitting diodes) are even
>>>> more efficient and will last days on 200 watts worth of power."
>>> No, LEDs are *not* more efficient.
>>>
>>> Nor will most humans be able to generate a continuous 200W. That's 1/4 horse power FFS !
>>>
>>> If that's their sales spiel then I don't think much of them.
>>>
>>> Graham
>> LEDs are better than incandescent lights,
>
> What do you mean by better ?
Much more mechanically robust, smaller, new and evolving technology, and
little thermal wasted on a hot filament.
>
>
>> maybe on par with fluorescents,
>
> Their efficiency in lumens / watt is currently typically no better than 50% of that of CFLs.
>
Even fluorescents make the light as a secondary effect. The ionized gas
inside makes UV which cause the phosphors to put out white light. A
black light is just a fluorescent without the white powder coating to
contain the UV and convert it to white.
>
>> and don't need a minimum voltage to run the electronic ballasts.
>
> In exactly what way don't they ?
The ballasts have a minimum workable voltage. Transistors optimized for
110 VAC rectified don't like low voltages. Same rules apply to bicycle
lights. The electronics package has to be optimum at some point.
The one thing that I can think of where voltage is of little concern is
with the new power supplies that will happily run on 80--24 VAC. They
are pretty well established in Europe but haven't shown up in the states
where we are behind the curve. Just look at the back of your computer
and see if there is a 110/220 switch.
>
>
>> I think 100 watts would be the output for an average person
>> and even that might be pushing it for a person in a developing country
>> who may not have enough good nutrition. At 100 watts, solar panels start
>> to be a major investment and don't work too good at night or on hazy
>> overcast days.
>
> I don't rate solar panels as an intelligent solution to today's energy issues either for ppl
> who live on-grid.
Why not? Even at only 20% efficiency they are better than fossil fuel.
That is the sticking point for right now. All kinds of money is being
spent on research to find a solar cell that goes to even 30%. If we
would just start buying what is available now instead of waiting for the
Nirvana of more efficient solar cells we might be digging out of our oil
problem.
>
> Graham
>
Not enough windy spots for windmills, unless of course they could be
utilized in a hurricane and suck up the power of nature on a rampage.
I know I'm dreaming on this one.
Bill Baka
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